WO2020049319A1

WO2020049319A1 - Methods for forming polycarbonate ether polyols and high molecular weight polyether carbonates

Info

Publication number: WO2020049319A1
Application number: PCT/GB2019/052499
Authority: WO
Inventors: Michael Kember; James LEELAND; Emmalina Hollis; Kerry Riley
Original assignee: Econic Technologies Ltd
Priority date: 2018-09-06
Filing date: 2019-09-06
Publication date: 2020-03-12
Also published as: WO2020049319A9; GB201814526D0

Abstract

Methods for preparing polycarbonate ether polyols and high molecular weight polyether carbonates and methods having improved control through controlled addition of materials during polymerisation are described. The method comprises the steps of: (I) (a) mixing catalyst of formula (I), double metal cyanide (DMC) catalyst and optionally carbon dioxide and/or solvent with epoxide and optionally starter compound and/or carbon dioxide to form mixture (α); or (b) mixing double metal cyanide (DMC) catalyst and optionally starter compound, carbon dioxide and/or solvent with epoxide and optionally carbon dioxide and/or solvent to form mixture (α); or (c) mixing epoxide, catalyst of formula (I), starter compound and carbon dioxide and optionally solvent to form mixture (α); or (d) mixing catalyst of formula (I), double metal cyanide (DMC) catalyst and optionally starter compound, epoxide, carbon dioxide and/or solvent to form mixture (α); and (II) adding one or more of starter compound, epoxide, carbon dioxide, catalyst of formula (I), double metal cyanide (DMC) catalyst and/or solvent to mixture (α) to form mixture (β) comprising starter compound, epoxide, carbon dioxide, catalyst of formula(I), double metal cyanide (DMC) catalyst and optionally solvent, wherein the catalyst of formula (I) has the following structure.

Description

METHODS FOR FORMING POLYCARBONATE ETHER POLYOLS AND HIGH

MOLECULAR WEIGHT POLYETHER CARBONATES

Technical field

The present invention relates to methods for preparing polycarbonate ether polyols and high molecular weight polyether carbonates. The present invention relates more particularly, but not necessarily exclusively, to methods having improved control through controlled addition of materials during polymerisation.

Background

Polycarbonate ether polyols are valuable as starting materials for the synthesis of polyurethanes. Polyurethanes are polymers which are prepared by reacting a di- or polyisocyanate with a polyol. Polyurethanes are used in many different products and applications, including as insulation panels, high performance adhesives, high-resilience foam seating, seals and gaskets, wheels and tyres, synthetic fibres, and the like.

Polyether carbonate polyols can be made by the catalytic addition of epoxides and carbon dioxide to a starter (compounds with H-functionality). One method of preparing polyether carbonate polyols is by using a double metal cyanide (DMC) catalyst. Such methods are described in US4500704, US6762278, W02006/103213, WO2015/022290.

“DMC” catalyst is a term commonly used in documents and published patents to refer to catalysts having at least two metal centres and a cyanide ligand. Many patents relating to methods for preparing the DMC catalyst and methods for preparing polyether using the DMC catalyst are disclosed [e.g. US 2008/0167502 (BASF); US 2003/0158449 (Bayer); US 2003/0069389 (Shell); US 2004/0220430 (Repsol Cuimica); US 5,536,883, EP0755716, US5482908, US5783513, (Arco); US 2005/0065383 (Dow), and US

3,427,256 (The General Tyre and Rubber Company)].

The polyether carbonate polyols formed by DMC catalysts generally have low carbon dioxide content (<20wt% CO2) and require high pressures such as 40 or 50 bar to incorporate such CO2 levels. W02006/103213 discloses a semi-batch process where an initial amount of epoxide (such as propylene oxide (PO)) is added to pre-activate the catalyst in the reactor in the presence of a starter, generating a polyether oligomer. The remaining epoxide and carbon dioxide is then metered into the reaction slowly to control the highly exothermic reaction and enable safe operation. This process has the disadvantage that the carbon dioxide content of the polyol is inherently lowered by the initial activation step in the absence of carbon dioxide, where the first segment of the chain contains only polyether linkages. The method is also limited to higher equivalent weight starters (such as polypropylene glycol 460) as lower equivalent weight starters (such as propylene glycol, PG, molecular mass 76 g/mol) inhibit the catalyst activation. Therefore, the method only generates moderate C0₂ content at higher molecular weights and cannot be used to incorporate any significant amount of CO2 into lower molecular weight polyols (<1500 Mn).

W02008/092767 discloses a semi-batch process using a DMC catalyst whereby an initial starter with higher equivalent weight (such as PPG-460) is charged into the reactor with the DMC catalyst for the activation step. A further, lower equivalent weight starter such as PG is metered into the reactor during reaction alongside the epoxide. This enables the use of lower weight starters as they do not hinder the reactivity after initiation, however the catalyst still has to be activated and a proportion of the polyol still contains the polyether product of the activation. The overall CO2 content is still only moderate under high pressures.

Operation under high pressures is disadvantageous for industrial scale preparation as it significantly increases cost and complexity of design.

WO2017/037441 discloses a batch method for producing polyether carbonate polyols using a dual catalyst system which enables operation under low pressures (such as 5-10 bar CO2) and can produce polyether carbonate polyols with a greatly increased CO2 content (>30wt% CO2). Such a batch operation, where all the epoxide is entered into the reactor at the start of the reaction would never be applicable industrially because of the possibility of a highly exothermic reaction occurring between the DMC catalyst and the epoxide.

WO 2012/121508 relates to a process for preparing polycarbonate ethers, which are ultimately intended for use as resins and soft plastics. The process disclosed in WO

2012/121508 requires the copolymerisation of an epoxide and carbon dioxide in the presence of a DMC catalyst and a metal salen catalyst. The examples are each carried out at 16 bar CO2 or above. The resulting polycarbonate ethers contain varying amounts of ether and carbonate linkages, with 0.67 carbonate (i.e. 67%) being the highest carbonate content achieved in WO 2012/121508, at a pressure of 28 bar. However, said polymers have a high molecular weight, have high polydispersity indices (that is, PDIs of 3.8 and above) and are not terminated by hydroxyl groups. These polymers cannot therefore be used to make polyurethanes. US2017/0247509 relates to a similar dual catalyst system using DMC catalysts and a metal salen complex, for the production of polyols. In this case, all the reactions are operated in a batch mode where all the propylene oxide is entered into the reactor at the start of the polymerisation. This is inherently unscalable as the risk of exothermic runaway reaction from the propylene oxide is too high.

Surprisingly, it has been found that such a dual catalyst system can be operated in a semi- continuous or continuous mode where the metering of one or more of the contents into the reactor during the reaction enables safe operation of this process and optimisation of the polyol structure and CO2 content. Furthermore, the semi-continuous or continuous process can be run without the need to pre-activate the DMC, enabling incorporation of CO2 from the beginning of the reaction, increasing the potential CO2 content of the polyol. The process can be operated using only low equivalent weight starters (such as 1 ,6-hexanediol, equivalent weight 118 g/mol) to produce a full range of molecular weight polyols with higher CO2 contents.

It has been found that continuous addition of the starter and the epoxide to the reactor enables the production of lower weight materials with appreciable CO2 content.

The process can also be surprisingly adopted in a continuous manner in the absence of a starter, to produce a polyether carbonate (e.g. a high molecular weight polyether carbonate).

The dual catalyst system of the present invention may be used in a polymerisation reaction that is carried out at temperatures which are not considered optimal in the art for either catalyst when used alone. For example, DMC catalysts generally operate effectively at relatively high temperatures, such as about 110-130°C.

In contrast, catalysts comprising salen or porphyrin ligands are known to be unstable at the temperatures typically used with DMC catalysts. In particular, if copolymerisation reactions are carried out at about 50°C or above, the metal in such ligands can undergo reduction to an inactive species. For example, the active metal centre Co(lll) in a cobalt salen catalyst may be reduced to an inactive Co(ll) species at high temperature. Consequently, such catalysts are typically used at temperatures below about 50°C (see Xia et al, Chem. Eur. J., 2015, 21 , 4384-4390). It is therefore surprising that the method of the present invention comprising both a DMC catalyst and a catalyst of formula (I) can be carried out at temperatures that are generally considered in the art to be unsuitable for the individual catalysts when used alone.

It is an object of the present invention to obviate or mitigate problems with existing methods for preparing polycarbonate ether polyols and/or methods for preparing high molecular weight polyether carbonates, and/or to provide an improved method, and/or to provide an alternative.

Summary of the Invention

According to the invention, there is provided a method for preparing a polycarbonate ether polyol, the method comprising the steps of:

(I) (a) mixing catalyst of formula (I), double metal cyanide (DMC) catalyst and

optionally carbon dioxide and/or solvent with epoxide and optionally starter compound and/or carbon dioxide to form mixture (a); or

(b) mixing double metal cyanide (DMC) catalyst and optionally starter compound, carbon dioxide and/or solvent with epoxide and optionally carbon dioxide and/or solvent to form mixture (a); or

(c) mixing epoxide, catalyst of formula (I), starter compound and carbon dioxide and optionally solvent to form mixture (a); or

(d) mixing catalyst of formula (I), double metal cyanide (DMC) catalyst and optionally starter compound, epoxide, carbon dioxide and/or solvent to form mixture (a); and

(II) adding one or more of starter compound, epoxide, carbon dioxide, catalyst of

formula (I), double metal cyanide (DMC) catalyst and/or solvent to mixture (a) to form mixture (b) comprising starter compound, epoxide, carbon dioxide, catalyst of formula (I), double metal cyanide (DMC) catalyst and optionally solvent,

wherein the catalyst of formula (I) has the following structure:

wherein:

M is a metal cation represented by M-(L)_V’;

is a multidentate ligand (e.g. it may be either (i) a tetradentate ligand, or (ii) two bidentate ligands);

(E)_m represents one or more activating groups attached to the ligand(s), where is a linker group covalently bonded to the ligand, each E is an activating functional group; and m is an integer from 1 to 4 representing the number of E groups present on an individual linker group;

L is a coordinating ligand, for example, L may be a neutral ligand, or an anionic ligand that is capable of ring-opening an epoxide;

v is an integer from 0 to 4; and

v’ is an integer that satisfies the valency of M, or is such that the complex

represented by formula (I) above has an overall neutral charge. For example, v’ may be 0, 1 or 2, e.g. v’ may be 1 or 2.

If v’ is 0 or if v’ is a positive integer and each L is a neutral ligand which is not capable of ring opening an epoxide, v is an integer from 1 to 4.

There is also provided a method for preparing high molecular weight polyether carbonates, the method comprising the steps of:

(I) (a) mixing catalyst of formula (I), double metal cyanide (DMC) catalyst and

optionally carbon dioxide and/or solvent with epoxide and optionally carbon dioxide to form mixture (a); or

(b) mixing double metal cyanide (DMC) catalyst and optionally carbon dioxide and/or solvent with epoxide and optionally carbon dioxide and/or solvent to form mixture (a); or

(c) mixing epoxide, catalyst of formula (I) and carbon dioxide and optionally solvent to form mixture (a); or (d) mixing catalyst of formula (I), double metal cyanide (DMC) catalyst and optionally epoxide, carbon dioxide and/or solvent to form mixture (a); and

(II) adding one or more of epoxide, carbon dioxide, catalyst of formula (I), double metal cyanide (DMC) catalyst and/or solvent to mixture (a) to form mixture (b) comprising epoxide, carbon dioxide, catalyst of formula (I), double metal cyanide (DMC) catalyst and optionally solvent,

wherein the catalyst of formula (I) has the following structure:

wherein:

M is a metal cation represented by M-(L)_V’;

v is an integer from 0 to 4; and

v’ is an integer that satisfies the valency of M, or is such that the complex

There is also provided a product obtainable by the methods described herein.

Definitions For the purpose of the present invention, an aliphatic group is a hydrocarbon moiety that may be straight chain (i.e. unbranched), branched, or cyclic and may be completely saturated, or contain one or more units of unsaturation, but which is not aromatic. The term “unsaturated” means a moiety that has one or more double and/or triple bonds. The term “aliphatic” is therefore intended to encompass alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl or cycloalkynyl groups, and combinations thereof.

An aliphatic group is optionally a C1 -30 aliphatic group, that is, an aliphatic group with 1 , 2, 3,

4, 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29 or

30 carbon atoms. Optionally, an aliphatic group is a Ci-isaliphatic, optionally a Ci-i2aliphatic, optionally a Ci-ioaliphatic, optionally a Ci-saliphatic, such as a Ci-₆aliphatic group. Suitable aliphatic groups include linear or branched, alkyl, alkenyl and alkynyl groups, and mixtures thereof such as (cycloalkyl)alkyl groups, (cycloalkenyl)alkyl groups and (cycloalkyl)alkenyl groups.

The term "alkyl," as used herein, refers to saturated, straight- or branched-chain

hydrocarbon radicals derived by removal of a single hydrogen atom from an aliphatic moiety. An alkyl group is optionally a“C1-20 alkyl group”, that is an alkyl group that is a straight or branched chain with 1 to 20 carbons. The alkyl group therefore has 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, 15, 16, 17, 18, 19 or 20 carbon atoms. Optionally, an alkyl group is a C1-15 alkyl, optionally a C1-12 alkyl, optionally a C_1-10 alkyl, optionally a C1-8 alkyl, optionally a Ci-e alkyl group. Specifically, examples of “C1-20 alkyl group" include methyl group, ethyl group, n- propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group, sec-pentyl, iso-pentyl, n-pentyl group, neopentyl, n-hexyl group, sec-hexyl, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n- tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-eicosyl group, 1 ,1-dimethylpropyl group, 1 ,2-dimethylpropyl group, 2,2-dimethylpropyl group, 1-ethylpropyl group, n-hexyl group, 1- ethyl-2-methylpropyl group, 1 ,1 ,2-trimethylpropyl group, 1-ethylbutyl group, 1-methylbutyl group, 2-methylbutyl group, 1 ,1-dimethylbutyl group, 1 ,2-dimethylbutyl group, 2,2- dimethylbutyl group, 1 ,3-dimethylbutyl group, 2,3-dimethylbutyl group, 2-ethylbutyl group, 2- methylpentyl group, 3-methylpentyl group and the like.

The term "alkenyl," as used herein, denotes a group derived from the removal of a single hydrogen atom from a straight- or branched-chain aliphatic moiety having at least one carbon-carbon double bond. The term "alkynyl," as used herein, refers to a group derived from the removal of a single hydrogen atom from a straight- or branched-chain aliphatic moiety having at least one carbon-carbon triple bond. Alkenyl and alkynyl groups are optionally“C2-2oalkenyl” and“C2-2oalkynyl”, optionally“C2-15 alkenyl” and“C2-15 alkynyl”, optionally“C2-12 alkenyl” and“C2-12 alkynyl”, optionally“C2-10 alkenyl” and“C2-10 alkynyl”, optionally“C2-8 alkenyl” and“C2-8 alkynyl”, optionally“C2-6 alkenyl” and“C2-6 alkynyl” groups, respectively. Examples of alkenyl groups include ethenyl, propenyl, allyl, 1 ,3-butadienyl, butenyl, 1-methyl-2-buten-1-yl, and allenyl. Examples of alkynyl groups include ethynyl, 2- propynyl (propargyl) and 1-propynyl.

The terms "cycloaliphatic", "carbocycle", or "carbocyclic" as used herein refer to a saturated or partially unsaturated cyclic aliphatic monocyclic or polycyclic (including fused, bridging and spiro-fused) ring system which has from 3 to 20 carbon atoms, that is an alicyclic group with 3, 4, 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, 15, 16, 17, 18, 19 or 20 carbon atoms. Optionally, an alicyclic group has from 3 to 15, optionally from 3 to 12, optionally from 3 to 10, optionally from 3 to 8 carbon atoms, optionally from 3 to 6 carbons atoms. The terms "cycloaliphatic", "carbocycle" or "carbocyclic" also include aliphatic rings that are fused to one or more aromatic or nonaromatic rings, such as tetrahydronaphthyl rings, where the point of attachment is on the aliphatic ring. A carbocyclic group may be polycyclic, e.g. bicyclic or tricyclic. It will be appreciated that the alicyclic group may comprise an alicyclic ring bearing one or more linking or non-linking alkyl substituents, such as -CH₂-cyclohexyl. Specifically, examples of carbocycles include cyclopropane, cyclobutane, cyclopentane, cyclohexane, bicyclo[2,2,1]heptane, norborene, phenyl, cyclohexene, naphthalene, spiro[4.5]decane, cycloheptane, adamantane and cyclooctane.

A heteroaliphatic group (including heteroalkyl, heteroalkenyl and heteroalkynyl) is an aliphatic group as described above, which additionally contains one or more heteroatoms. Heteroaliphatic groups therefore optionally contain from 2 to 21 atoms, optionally from 2 to 16 atoms, optionally from 2 to 13 atoms, optionally from 2 to 11 atoms, optionally from 2 to 9 atoms, optionally from 2 to 7 atoms, wherein at least one atom is a carbon atom. Optional heteroatoms are selected from O, S, N, P and Si. When heteroaliphatic groups have two or more heteroatoms, the heteroatoms may be the same or different. Heteroaliphatic groups may be substituted or unsubstituted, branched or unbranched, cyclic or acyclic, and include saturated, unsaturated or partially unsaturated groups.

An alicyclic group is a saturated or partially unsaturated cyclic aliphatic monocyclic or polycyclic (including fused, bridging and spiro-fused) ring system which has from 3 to 20 carbon atoms, that is an alicyclic group with 3, 4, 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, 15, 16, 17, 18, 19 or 20 carbon atoms. Optionally, an alicyclic group has from 3 to 15, optionally from 3 to 12, optionally from 3 to 10, optionally from 3 to 8 carbon atoms, optionally from 3 to 6 carbons atoms. The term“alicyclic” encompasses cycloalkyl, cycloalkenyl and cycloalkynyl groups. It will be appreciated that the alicyclic group may comprise an alicyclic ring bearing one or more linking or non-linking alkyl substituents, such as -CH₂-cyclohexyl. Specifically, examples of the C3-20 cycloalkyl group include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl and cyclooctyl.

A h ete roa I i cyclic group is an alicyclic group as defined above which has, in addition to carbon atoms, one or more ring heteroatoms, which are optionally selected from O, S, N, P and Si. Heteroalicyclic groups optionally contain from one to four heteroatoms, which may be the same or different. Heteroalicyclic groups optionally contain from 5 to 20 atoms, optionally from 5 to 14 atoms, optionally from 5 to 12 atoms.

An aryl group or aryl ring is a monocyclic or polycyclic ring system having from 5 to 20 carbon atoms, wherein at least one ring in the system is aromatic and wherein each ring in the system contains three to twelve ring members. The term "aryl" can be used alone or as part of a larger moiety as in "aralkyl", "aralkoxy", or "aryloxyalkyl”. An aryl group is optionally a“Ce aryl group” and is an aryl group constituted by 6, 7, 8, 9, 10, 11 or 12 carbon atoms and includes condensed ring groups such as monocyclic ring group, or bicyclic ring group and the like. Specifically, examples of“Ce-io aryl group” include phenyl group, biphenyl group, indenyl group, anthracyl group, naphthyl group or azulenyl group and the like. It should be noted that condensed rings such as indan, benzofuran, phthalimide,

phenanthridine and tetrahydro naphthalene are also included in the aryl group.

The term "heteroaryl" used alone or as part of another term (such as "heteroaralkyl", or "heteroaralkoxy") refers to groups having 5 to 14 ring atoms, optionally 5, 6, or 9 ring atoms; having 6, 10, or 14 p electrons shared in a cyclic array; and having, in addition to carbon atoms, from one to five heteroatoms. The term "heteroatom" refers to nitrogen, oxygen, or sulfur, and includes any oxidized form of nitrogen or sulfur, and any quaternized form of nitrogen. The term "heteroaryl" also includes groups in which a heteroaryl ring is fused to one or more aryl, cycloaliphatic, or heterocyclyl rings, where the radical or point of attachment is on the heteroaromatic ring. Examples include indolyl, isoindolyl, benzothienyl, benzofuranyl, dibenzofuranyl, indazolyl, benzimidazolyl, benzthiazolyl, quinolyl, isoquinolyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, 4H-quinolizinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, and pyrido[2,3-b]-1 ,4-oxazin-3(4H)-one. Thus, a heteroaryl group may be mono- or polycyclic. The term "heteroaralkyl" refers to an alkyl group substituted by a heteroaryl, wherein the alkyl and heteroaryl portions independently are optionally substituted.

As used herein, the terms "heterocycle", "heterocyclyl", "heterocyclic radical", and

"heterocyclic ring" are used interchangeably and refer to a stable 5- to 7-membered monocyclic or 7-14-membered bicyclic heterocyclic moiety that is saturated, partially unsaturated, or aromatic and having, in addition to carbon atoms, one or more, optionally one to four, heteroatoms, as defined above. When used in reference to a ring atom of a heterocycle, the term "nitrogen" includes a substituted nitrogen.

Examples of alicyclic, heteroalicyclic, aryl and heteroaryl groups include but are not limited to cyclohexyl, phenyl, acridine, benzimidazole, benzofuran, benzothiophene, benzoxazole, benzothiazole, carbazole, cinnoline, dioxin, dioxane, dioxolane, dithiane, dithiazine, dithiazole, dithiolane, furan, imidazole, imidazoline, imidazolidine, indole, indoline, indolizine, indazole, isoindole, isoquinoline, isoxazole, isothiazole, morpholine, napthyridine, oxazole, oxadiazole, oxathiazole, oxathiazolidine, oxazine, oxadiazine, phenazine, phenothiazine, phenoxazine, phthalazine, piperazine, piperidine, pteridine, purine, pyran, pyrazine, pyrazole, pyrazoline, pyrazolidine, pyridazine, pyridine, pyrimidine, pyrrole, pyrrolidine, pyrroline, quinoline, quinoxaline, quinazoline, quinolizine, tetrahydrofuran, tetrazine, tetrazole, thiophene, thiadiazine, thiadiazole, thiatriazole, thiazine, thiazole, thiomorpholine, thianaphthalene, thiopyran, triazine, triazole, and trithiane.

The term“halide”,“halo” and“halogen” are used interchangeably and, as used herein mean a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, optionally a fluorine atom, a bromine atom or a chlorine atom, and optionally a fluorine atom.

A haloalkyl group is optionally a“C_1-20 haloalkyl group”, optionally a“C_1-15 haloalkyl group”, optionally a“C_1.12 haloalkyl group”, optionally a“C_1-10 haloalkyl group”, optionally a“C_1-8 haloalkyl group”, optionally a “C_1-6 haloalkyl group” and is a C_1-20 alkyl, a C_1-15 alkyl, a C_1-12 alkyl, a C_1-10 alkyl, a Ci-e alkyl, or a Ci-e alkyl group, respectively, as described above substituted with at least one halogen atom, optionally 1 , 2 or 3 halogen atom(s). The term “haloalkyl” encompasses fluorinated or chlorinated groups, including perfluorinated compounds. Specifically, examples of“C_1-20 haloalkyl group” include fluoromethyl group, difluoromethyl group, trifluoromethyl group, fluoroethyl group, difluroethyl group, trifluoroethyl group, chloromethyl group, bromomethyl group, iodomethyl group and the like.

The term "acyl" as used herein refers to a group having a formula -C(O)R where R is hydrogen or an optionally substituted aliphatic, aryl, or heterocyclic group. An alkoxy group is optionally a“C_1-20 alkoxy group”, optionally a“C_1-15 alkoxy group”, optionally a“ C_1-12 alkoxy group”, optionally a“C_1-10 alkoxy group”, optionally a“C_1-8 alkoxy group”, optionally a“C_1-6 alkoxy group” and is an oxy group that is bonded to the previously defined C_1-20 alkyl, C_1-15 alkyl, C_1-12 alkyl, C_1-10 alkyl, Ci-e alkyl, or Ci-e alkyl group

respectively. Specifically, examples of“C_1-20 alkoxy group” include methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, iso-butoxy group, sec-butoxy group, tert-butoxy group, n-pentyloxy group, iso-pentyloxy group, sec-pentyloxy group, n- hexyloxy group, iso-hexyloxy group, , n-hexyloxy group, n-heptyloxy group, n-octyloxy group, n-nonyloxy group, n-decyloxy group, n-undecyloxy group, n-dodecyloxy group, n-tridecyloxy group, n-tetradecyloxy group, n-pentadecyloxy group, n-hexadecyloxy group, n- heptadecyloxy group, n-octadecyloxy group, n-nonadecyloxy group, n-eicosyloxy group, 1 ,1-dimethylpropoxy group, 1 ,2-dimethylpropoxy group, 2,2-dimethylpropoxy group, 2- methylbutoxy group, 1-ethyl-2-methylpropoxy group, 1 ,1 ,2-trimethylpropoxy group, 1 ,1- dimethylbutoxy group, 1 ,2-dimethylbutoxy group, 2,2-dimethylbutoxy group, 2,3- dimethylbutoxy group, 1 ,3-dimethylbutoxy group, 2-ethylbutoxy group, 2-methylpentyloxy group, 3-methylpentyloxy group and the like.

An aryloxy group is optionally a “C5-20 aryloxy group”, optionally a “Ce-12 aryloxy group”, optionally a“C_{M O} aryloxy group” and is an oxy group that is bonded to the previously defined C5-20 aryl, C_M2 aryl, or C_{M O} aryl group respectively.

An alkylthio group is optionally a“C_1-20 alkylthio group”, optionally a“C_1-15 alkylthio group”, optionally a“ C_1-12 alkylthio group”, optionally a“C_1-10 alkylthio group”, optionally a“C_1-8 alkylthio group”, optionally a“C_1-6 alkylthio group” and is a thio (-S-) group that is bonded to the previously defined C_1-20 alkyl, C_1-15 alkyl, C_1-12 alkyl, C_1-10 alkyl, Ci-e alkyl, or Ci-e alkyl group respectively.

An arylthio group is optionally a“C5-20 arylthio group”, optionally a“C_6-12 arylthio group”, optionally a“C_6-10 arylthio group” and is a thio (-S-) group that is bonded to the previously defined C5-20 aryl, C_6-12 aryl, or C_6-10 aryl group respectively.

An alkylaryl group is optionally a“C_6-12 aryl C_1-20 alkyl group”, optionally a “C_6-12 ryl C_6-10 alkyl group”, optionally a“C_6-12 aryl C1 -6 alkyl group” and is an aryl group as defined above bonded at any position to an alkyl group as defined above. The point of attachment of the alkylaryl group to a molecule may be via the alkyl portion and thus, optionally, the alkylaryl group is -CH₂-Ph or -CH₂CH₂ -Ph. An alkylaryl group can also be referred to as“aralkyl”. A silyl group is optionally -Si(R₁)₃, wherein each R₁ can be independently an aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl group as defined above.

Optionally, each R₁ is independently an unsubstituted aliphatic, alicyclic or aryl. Optionally, each R₁ is an alkyl group selected from methyl, ethyl or propyl.

A silyl ether group is optionally a group OSi(R₂)₃ wherein each R₂ can be independently an aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl group as defined above. Each R₂ can be independently an unsubstituted aliphatic, alicyclic or aryl. Optionally, each R₂ is an optionally substituted phenyl or optionally substituted alkyl group selected from methyl, ethyl, propyl or butyl (such as n-butyl (ⁿBu) or tert-butyl fBu)). Exemplary silyl ether groups include OSi(Me)₃, OSi(Et)₃, OSi(Ph)₃, OSi(Me)₂(‘Bu), OSi(‘Bu)₃ and OSi(Ph)₂(‘Bu).

A nitrile group (also referred to as a cyano group) is a group CN.

An imine group is a group -CR₃NR₃, optionally -CHNR₃ wherein R₃ is an aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl group as defined above. R₃ may be unsubstituted aliphatic, alicyclic or aryl. Optionally R₃ is an alkyl group selected from methyl, ethyl or propyl.

An acetylide group contains a triple bond -CºC-R₄, optionally wherein R₄ can be hydrogen, an aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl group as defined above. For the purposes of the invention when R₄ is alkyl, the triple bond can be present at any position along the alkyl chain. R₄ may be unsubstituted aliphatic, alicyclic or aryl.

Optionally R₄ is methyl, ethyl, propyl or phenyl.

An amino group is optionally -NH₂, -NHR₅ or -N(R₅)₂ wherein R₅ can be an aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, a silyl group, aryl or heteroaryl group as defined above. It will be appreciated that when the amino group is N(R₅)₂, each R₅ group can be the same or different. Each R₅ may independently an unsubstituted aliphatic, alicyclic, silyl or aryl. Optionally R₅ is methyl, ethyl, propyl, SiMe₃ or phenyl.

An amido group is optionally -NR₆C(O)- or -C(O)-NR₆- wherein R₆ can be hydrogen, an aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl group as defined above. R₆ may be unsubstituted aliphatic, alicyclic or aryl. Optionally R₆ is hydrogen, methyl, ethyl, propyl or phenyl. The amido group may be terminated by hydrogen, an aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl group. An ester group is optionally -0C(O)R₇- or -C(O)OR₇- wherein R₇ can be an aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl group as defined above. R₇ may be unsubstituted aliphatic, alicyclic or aryl. Optionally R₇ is methyl, ethyl, propyl or phenyl. The ester group may be terminated by an aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl group. It will be appreciated that if R₇ is hydrogen, then the group defined by -0C(O)R₇- or -C(O)OR₇- will be a carboxylic acid group.

A sulfoxide is optionally -S(O)Rs and a sulfonyl group is optionally -S(O)₂Rs wherein Rs can be an aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl group as defined above. Rs may be unsubstituted aliphatic, alicyclic or aryl. Optionally Rs is methyl, ethyl, propyl or phenyl.

A carboxylate group is optionally -OC(O)Rg_, wherein Rg can be hydrogen, an aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl group as defined above. Rg may be unsubstituted aliphatic, alicyclic or aryl. Optionally Rg is hydrogen, methyl, ethyl, propyl, butyl (for example n-butyl, isobutyl or tert-butyl), phenyl, pentafluorophenyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, trifluoromethyl or adamantyl.

An acetamide is optionally MeC(O)N(R₁o)₂ wherein R10 can be hydrogen, an aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl group as defined above. R10 may be unsubstituted aliphatic, alicyclic or aryl. Optionally R10 is hydrogen, methyl, ethyl, propyl or phenyl.

A phosphinate group is optionally-OP(O)(R_{1 1})₂ or -P(O)(OR_{1 1})(R_{1 1}) wherein each R_{1 1} is independently selected from hydrogen, or an aliphatic, heteroaliphatic, alicyclic,

heteroalicyclic, aryl or heteroaryl group as defined above. R_{1 1} may be aliphatic, alicyclic or aryl, which are optionally substituted by aliphatic, alicyclic, aryl or C_1-6alkoxy. Optionally R_{1 1} is optionally substituted aryl or C1-20 alkyl, optionally phenyl optionally substituted by Ci- ₆alkoxy (optionally methoxy) or unsubstituted Ci-2oalkyl (such as hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, stearyl). A phosphonate group is optionally -P(O)(OR₁1)2 wherein R_{1 1} is as defined above. It will be appreciated that when either or both of R_{1 1} is hydrogen for the group -P(O)(OR_{1 1})₂, then the group defined by -P(O)(OR_{1 1})₂will be a phosphonic acid group. A sulfinate group is optionally -S(O)OR₁₂ or -0S(O)R₁₂ wherein R₁₂ can be hydrogen, an aliphatic, heteroaliphatic, haloaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl group as defined above. R₁₂ may be unsubstituted aliphatic, alicyclic or aryl. Optionally R₁₂ is hydrogen, methyl, ethyl, propyl or phenyl. It will be appreciated that if R₁₂ is hydrogen, then the group defined by -S(O)OR₁₂ will be a sulfonic acid group.

A carbonate group is optionally -OC(O)O R_13, wherein R₁₃ can be hydrogen, an aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl group as defined above. R₁₃ may be optionally substituted aliphatic, alicyclic or aryl. Optionally R₁₃ is hydrogen, methyl, ethyl, propyl, butyl (for example n-butyl, isobutyl or tert-butyl), phenyl, pentafluorophenyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, trifluoromethyl, cyclohexyl, benzyl or adamantyl. It will be appreciated that if R₁₃ is hydrogen, then the group defined

by -OC(O)OR₁₃ will be a carbonic acid group.

In an -alkylC(O)OR₁₄ or -alkylC(O) R₁₄ group, R_{1 1} can be hydrogen, an aliphatic,

heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl group as defined above. R₁₄ may be unsubstituted aliphatic, alicyclic or aryl. Optionally R₁₄ is hydrogen, methyl, ethyl, propyl, butyl (for example n-butyl, isobutyl or tert-butyl), phenyl, pentafluorophenyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, trifluoromethyl or adamantyl.

It will be appreciated that where any of the above groups are present in a Lewis base, one or more additional R groups may be present, as appropriate, to complete the valency. For example, in the context of an amino group, an additional R group may be present to give RNHR₅, wherein R is hydrogen, an optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl group as defined above. Optionally, R is hydrogen or aliphatic, alicyclic or aryl.

As used herein, the term“optionally substituted” means that one or more of the hydrogen atoms in the optionally substituted moiety is replaced by a suitable substituent. Unless otherwise indicated, an "optionally substituted” group may have a suitable substituent at each substitutable position of the group, and when more than one position in any given structure may be substituted with more than one substituent selected from a specified group, the substituent may be either the same or different at every position. Combinations of substituents envisioned by this invention are optionally those that result in the formation of stable compounds. The term "stable", as used herein, refers to compounds that are chemically feasible and can exist for long enough at room temperature i.e. (16-25°C) to allow for their detection, isolation and/or use in chemical synthesis.

Substituents may be depicted as attached to a bond that crosses a bond in a ring of the depicted molecule. This convention indicates that one or more of the substituents may be attached to the ring at any available position (usually in place of a hydrogen atom of the structure). In cases where an atom of a ring has two substitutable positions, two groups (either the same or different) may be present on that atom.

Optional substituents for use in the present invention include, but are not limited to, halogen, hydroxy, nitro, carboxylate, carbonate, alkoxy, aryloxy, alkylthio, arylthio, heteroaryloxy, alkylaryl, amino, amido, imine, nitrile, silyl, silyl ether, ester, sulfoxide, sulfonyl, acetylide, phosphinate, sulfonate or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl groups (for example, optionally substituted by halogen, hydroxy, nitro, carbonate, alkoxy, aryloxy, alkylthio, arylthio, amino, imine, nitrile, silyl, sulfoxide, sulfonyl, phosphinate, sulfonate or acetylide).

Preferred optional substituents for use in the present invention are selected from nitro, C_1-12 alkoxy (e.g. OMe, OEt, O'Pr, OⁿBu, 0‘Bu), Ce-ie aryl, C_2-14 heteroaryl, C_2-14 heteroalicyclic, C_1-6 alkyl, Ci-e haloalkyl, F, Cl, Br, I and OH, wherein in each of said C_1-12 alkoxy, Ce-i_b aryl, C_2-14 heteroaryl, C_2-14 heteroalicyclic, C_1-6 alkyl and C_1-6 haloalkyl group may be optionally substituted by an optional substituent as defined herein.

As used herein, the term“protecting group” is used to denote a functional group that can be used to mask the reactivity of another functional group. For example, in chemical synthesis, it is often necessary to mask the reactivity of an acidic hydrogen atom on a hydroxyl group, to allow a reaction to take place at another site on the molecule. The hydroxyl group can therefore be“protected” or its reactivity can be“masked” through a reaction with another compound, which can then be removed later in the chemical synthesis, in a step known as “deprotection”.

A variety of protecting groups are described in Protecting Groups in Organic Synthesis by Wuts and Greene, 4th edition, John Wiley & Sons, Inc. 2006, the entirety of which is incorporated herein by reference.

Suitable protecting groups for oxygen (e.g. hydroxyl groups) for use in the present invention include acetyl groups, benzoyl groups, benzyl groups, b-methoxymethylether (MEM) groups, [bis-(4-methoxyphenyl)phenylmethyl] (DMT) groups, methoxymethyl ether (MOM) groups, methoxytrityl [(4-methoxyphenyl)diphenylmethyl] (MMT) groups, p-methoxybenzyl ether (PMB) groups, methylthiomethyl ether groups, pivaloyl (Piv) groups, tetrahydropyranyl (THP) groups, tetrahydrofuran (THF) groups, trityl (triphenylmethyl, Tr) groups, silyl ether groups including trimethylsilyl (TMS) groups, tert-butyldimethylsilyl (TBDMS) groups, tri-iso- propylsilyloxymethyl (TOM) groups, and triisopropylsilyl (TIPS) groups, methyl ethers and ethoxyethyl ethers.

Suitable protecting groups for nitrogen (e.g. amine groups) for use in the present invention include carbobenzyloxy (Cbz) groups, p-methoxybenzyl carbonyl (Moz or MeOZ) groups, tert-butyloxycarbonyl (BOC) groups, 9-fluorenylmethyloxycarbonyl (FMOC) groups, acetyl (Ac) groups, benzoyl (Bz) groups, benzyl (Bn) groups, carbamate groups, p-methoxybenzyl (PMB) groups, 3,4-dimethoxybenzyl (DMPM) groups, p-methoxyphenyl (PMP) groups, trichloroethyl chloroformate (Troc) groups, 4-nitro-benzene-1-sulfonyl (Nosyl) groups and 2- nitrophenylsulfonyl (Nps) groups.

Suitable protecting groups for phosphorus, such as might be found on a phosphonate or phosphate group, for use in the present invention include alkyl esters (such as methyl, ethyl and tert-butyl esters), allyl esters (such as vinyl esters), 2-cyanoethyl esters,

s-(trifluoromethylsilyl)ethyl esters, 2-(methylsulfonyl)ethyl esters and 2,2,2-trichloroethyl esters.

For the purposes of the present invention, the epoxide substrate is not limited. The term epoxide therefore relates to any compound comprising an epoxide moiety (i.e. a substituted or unsubstituted oxirane compound). Substituted oxiranes include monosubstituted oxiranes, disubstituted oxiranes, trisubstituted oxiranes, and tetrasubstituted oxiranes.

Epoxides may comprise a single oxirane moiety. Epoxides may comprise two or more oxirane moieties.

Examples of epoxides which may be used in the present invention include, but are not limited to, cyclohexene oxide, styrene oxide, ethylene oxide, propylene oxide, butylene oxide, substituted cyclohexene oxides (such as limonene oxide, C10H16O or 2-(3,4- epoxycyclohexyl)ethyltrimethoxysilane, C1 1H22O), alkylene oxides (such as ethylene oxide and substituted ethylene oxides), unsubstituted or substituted oxiranes (such as oxirane, epichlorohydrin, 2-(2-methoxyethoxy)methyl oxirane (MEMO), 2-(2-(2- methoxyethoxy)ethoxy)methyl oxirane (ME2MO), 2-(2-(2-(2- methoxyethoxy)ethoxy)ethoxy)methyl oxirane (ME3MO), 1 ,2-epoxybutane, glycidyl ethers, vinyl-cyclohexene oxide, 3-phenyl-1 , 2-epoxypropane, 1 ,2- and 2,3-epoxybutane, isobutylene oxide, cyclopentene oxide, 2,3-epoxy-1 ,2,3,4-tetrahydronaphthalene, indene oxide, and functionalized 3,5-dioxaepoxides. Examples of functionalized 3,5-dioxaepoxides include:

The epoxide moiety may be a glycidyl ether, glycidyl ester or glycidyl carbonate. Examples of glycidyl ethers, glycidyl esters glycidyl carbonates include:

As noted above, the epoxide substrate may contain more than one epoxide moiety, i.e. it may be a bis-epoxide, a tris-epoxide, or a multi-epoxide containing moiety. Examples of compounds including more than one epoxide moiety include bisphenol A diglycidyl ether and 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate. It will be understood that reactions carried out in the presence of one or more compounds having more than one epoxide moiety may lead to cross-linking in the resulting polymer.

The skilled person will appreciate that the epoxide can be obtained from“green” or renewable resources. The epoxide may be obtained from a (poly)unsaturated compound, such as those deriving from a fatty acid and/or terpene, obtained using standard oxidation chemistries.

The epoxide moiety may contain -OH moieties, or protected -OH moieties. The -OH moieties may be protected by any suitable protecting group. Suitable protecting groups include methyl or other alkyl groups, benzyl, allyl, tert-butyl, tetrahydropyranyl (THP), methoxymethyl (MOM), acetyl (C(O)alkyl), benzolyl (C(O)Ph), dimethoxytrityl (DMT), methoxyethoxymethyl (MEM), p-methoxybenzyl (PMB), trityl, silyl (such as trimethylsilyl (TMS), t-butyldimethylsilyl (TBDMS), t-butyldiphenylsilyl (TBDPS), tri-iso- propylsilyloxymethyl (TOM), and trilsopropylsilyl (TIPS)), (4-methoxyphenyl)diphenyimethyl (MMT), tetrahydrofuranyl (THF), and tetrahydropyranyl (THP).

The epoxide optionally has a purity of at least 98%, optionally >99%.

It will be understood that the term“an epoxide” is intended to encompass one or more epoxides. In other words, the term“an epoxide” refers to a single epoxide, or a mixture of two or more different epoxides. For example, the epoxide substrate may be a mixture of ethylene oxide and propylene oxide, a mixture of cyclohexene oxide and propylene oxide, a mixture of ethylene oxide and cyclohexene oxide, or a mixture of ethylene oxide, propylene oxide and cyclohexene oxide.

Polyether carbonate and polycarbonate ether is used herein interchangeably and both refer to a polymer having multiple ether and multiple carbonate linkages.

The term polyether carbonate polyol generally refers to polymers which are substantially terminated at each end with -OH, -SH, and/or -NHR’ groups (encompassing C-OH,

P-OH, -C(O)0H, etc. moieties). R’ may be H, or optionally substituted alkyl, heteroalkyl, aryl, heteroaryl, cycloalkyl or heterocycloalkyl, optionally R’ is H or optionally substituted alkyl. By way of example, at least about 90%, at least about 95%, at least about 98% or at least about 99% of polymers may be terminated at each end with -OH groups. The skilled person will appreciate that if the polymer is linear, then it may be capped at both ends with -OH groups. If the polymer is branched, each of the branches may be capped with -OH groups. Such polymers are generally useful in preparing higher polymers such as polyurethanes.

The chains may comprise a mixture of functional groups (e.g. -OH and -SH) groups, or may contain the same functional group (e.g. all-OH groups).

The term“continuous” used herein can be defined as the mode of addition of materials or may refer to the nature of the reaction method as a whole.

In terms of continuous mode of addition, the relevant materials are continually or constantly added during the course of a reaction. This may be achieved by, for example, adding a stream of material with either a constant flow rate or with a variable flow rate. In other words, the one or more materials are added in an essentially non-stop fashion. It is noted, however, that non-stop addition of the materials may need to be briefly interrupted for practical considerations, for example to refill or replace a container of the materials from which these materials are being added.

In terms of a whole reaction being continuous, the reaction may be conducted over a long period of time, such as a number of days, weeks, months, etc. In such a continuous reaction, reaction materials may be continually topped-up and/or products of the reaction may be tapped-off. It will be appreciated that although catalysts may not be consumed during a reaction, catalysts may in any case require topping-up, since tapping-off may deplete the amount of catalyst present.

A continuous reaction may employ continuous addition of materials.

The term“discontinuous” used herein means that the addition of the materials takes place in a portion-wise manner. This may be achieved by, for example, dropwise addition of the materials. Alternatively, the materials may be added in portions (i.e. batch fed) into the vessel, with timed intervals between additions. These timed intervals may be regular, or may change during the course of the reaction. Such timed intervals may be as little as a few minutes, or may be several hours. For example, the timed intervals may be between 1 minute and 12 hours; between 5 minutes and 6 hours; between 10 minutes and 4 hours; between 15 minutes and 3 hours; between 20 minutes and 2 hours; or between 30 minutes and 1 hour. If the materials are to be added in portions (i.e. batch fed), then there must be at least two discrete additions of the materials during the course of the reaction as a whole.

A continuous reaction may employ a discontinuous (i.e. batch-wise) addition of materials.

Detailed Description

The present invention relates to continuous and discontinuous methods for preparing polycarbonate ether polyols, by reacting an epoxide and carbon dioxide in the presence of a catalyst of formula (I), a double metal cyanide (DMC) catalyst and a starter compound.

The present invention further relates to continuous and discontinuous methods for preparing high molecular weight polyether carbonates, by reacting an epoxide and carbon dioxide in the presence of a catalyst of formula (I), and a double metal cyanide (DMC) catalyst.

Accordingly, the present invention relates to a method for preparing a polycarbonate ether polyol, the method comprising the steps of:

(I) (a) mixing catalyst of formula (I), double metal cyanide (DMC) catalyst and

wherein the catalyst of formula (I) has the following structure:

wherein:

M is a metal cation represented by M-(L)_V’;

v is an integer from 0 to 4; and

v’ is an integer that satisfies the valency of M, or is such that the complex

represented by formula (I) above has an overall neutral charge. For example, v’ may be 0, 1 or 2, e.g. v’ may be 1 or 2. If v’ is 0 or if v’ is a positive integer and each L is a neutral ligand which is not capable of ring opening an epoxide, v is an integer from 1 to 4.

The present invention relates to methods for preparing polycarbonate ether polyols and high molecular weight polyether carbonates. The method is conducted in two or more stages. In this way, part of the reaction is allowed to start and then more of one or more of the reaction materials are added (in either a continuous or discontinuous manner) as the reaction continues.

Adding certain components in the second step may be useful to increase activity of the catalysts and may lead to a more efficient process, compared with a process in which all of the materials are provided at the start of the reaction. Large amounts of some of the components present throughout the reaction may reduce efficiency of the catalysts. Adding material slowly to the reaction may prevent this reduced efficiency of the catalysts and/or may optimise catalyst activity. Additionally, not loading the total amount of each component at the start of the reaction may lead to even catalysis, and more uniform polymer products. This in turn may lead to polymers having a narrower molecular weight distribution, desired ratio of ether to carbonate linkages, and/or an improved (i.e. a lower) polydispersity index.

Mixing only certain components in the first step and adding the remainder in the second step may also be useful for pre-activating catalysts. Such pre-activation may be achieved by mixing one or both catalysts with epoxide (and optionally other components), per step (l)(a) or (b) above. Pre-activation may be useful to prime one or both catalyst such that, upon addition of the remaining components in step (II), the efficiency of the reaction may increase.

It will be appreciated that the present invention relates to a reaction in which carbonate and ether linkages are added to a growing polymer chain. Mixing only certain components in the first step and adding the remainder in the second step may be useful for allowing part of the reaction to proceed before a second stage in the reaction. By way of example, mixing epoxide, catalyst of formula (I), starter compound and carbon dioxide and optionally solvent, per step (l)(c) above, may permit growth of a polymer having a high number of carbonate linkages. Thereafter, adding the remaining components (including the DMC catalyst) permits the reaction to proceed by adding ether linkages (as well as continuing to add carbonate linkages) to the growing polymer chain.

In general terms, an aim of the present invention is to control the polymerisation reaction through controlled addition of materials. The methods herein may allow the product prepared by such methods to be tailored to the necessary requirements.

Mixture (a) formed by steps (l)(a) or (b) may be held at a temperature of between about 50 to 150°C prior to step (II), optionally between about 80 to 130°C.

Mixture (a) formed by steps (l)(c) or (d) may be held at a temperature of between about 0 to 120°C prior to step (II), optionally between about 40 to 100°C, optionally between about 50 to 90°C.

Mixture (a) may be held for at least about 1 minute prior to step (II), optionally at least about 5 minutes, optionally at least about 15 minutes, optionally at least about 30 minutes, optionally at least about 1 hour, optionally at least about 2 hours, optionally at least about 5 hours. Mixture (a) formed by steps (l)(c) may be held for at least about 1 minute prior to step (II), optionally at least about 5 minutes, optionally at least about 15 minutes, optionally at least about 30 minutes, optionally at least about 1 hour, optionally at least about 2 hours, optionally at least about 3 hours, optionally at least about 4 hours, optionally at least about 8 hours, optionally at least about 16 hours.

Mixture (a) may comprise less than about 1 wt.% water, optionally less than about 0.5 wt.% water, optionally less than about 0.1 wt.% water, optionally less than about 0.05 wt.% water, optionally about 0 wt.% water. The presence of water in the mixture may cause de activation of the or each catalyst. Thus, minimising the water content in the mixture is desired.

Step (l)(a) may comprise firstly mixing catalyst of formula (I), double metal cyanide (DMC) catalyst and optionally carbon dioxide to form mixture (a’), and subsequently adding epoxide and optionally starter compound and/or carbon dioxide to form mixture (a). Conducting the method in this way may be useful for pre-activating one or both catalysts, as previously described.

Mixture (a’) may be held at a temperature of between about 0 to 250°C prior to said subsequently adding, optionally about 40 to 150°C, optionally about 50 to 150°C, optionally about 70 to 140°C, optionally about 80 to 130°C.

Subsequent to step (l)(c), step (II) may comprise mixing double metal cyanide (DMC) catalyst epoxide, and optionally starter compound, carbon dioxide and/or solvent to form a pre-activated mixture and adding the pre-activated mixture to mixture (a) to form mixture (b).

The pre-activated mixture may be held at a temperature of between about 10 to 110°C prior to adding, optionally between about 25 to 80°C.

The reaction method as a whole may be conducted on a batch-wise basis. In such instances, the method may employ a total amount of each of the relevant materials used in the reaction (such as the epoxide, starter compound, etc.), and a proportion of that total amount may be added in different steps in the reaction.

The method may employ a total amount of epoxide, and wherein about 1 to 95% of the total amount of epoxide may be mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

The method may employ a total amount of starter compound, and wherein about 1 to 95% of the total amount of starter compound may be mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

The method may employ a total amount of catalyst of formula (I), and wherein about 1 to 100% of the total amount of catalyst of formula (I) may be mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

The method may employ a total amount of double metal cyanide (DMC) catalyst, and wherein about 1 to 100% of the total amount of double metal cyanide (DMC) catalyst may be mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

The method may employ a total amount of carbon dioxide, and wherein about 1 to 100% of the total amount of carbon dioxide may be mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

The method may employ a total amount of solvent, and wherein about 1 to 100% of the total amount of solvent may be mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

The total amount of the catalyst of formula (I) may be low, such that the methods of the invention may be carried out at low catalytic loading. For example, the catalytic loading of the catalyst of formula (I) may be in the range of about 1 : 100,000-300,000 [total catalyst of formula (l)]:[total epoxide], such as about 1 :10,000-100,000 [total catalyst of formula (l)]:[total epoxide], e.g. in the region of about 1 :10,000-50,000 [total catalyst of formula (l)]:[total epoxide], for example in the region of about 1 :10,000 [total catalyst of formula (l)]:[total epoxide]. The ratios above are molar ratios. These ratios are the ratios of the total amount of catalyst of formula (I) to the total amount of epoxide used in the method.

The method may be continuous, wherein there is a predetermined molar ratio or weight ratio of epoxide to catalyst of formula (I) in mixture (b), and wherein the method further comprises:

(III) adding epoxide to mixture (b) to form mixture (y), said epoxide being added at an amount sufficient to bring the molar ratio or weight ratio of epoxide to catalyst of formula (I) in mixture (g) to at least about 75% of said predetermined molar ratio or weight ratio, optionally wherein step (III) is repeated.

The method may be continuous, wherein there is a predetermined molar ratio or weight ratio of starter compound to catalyst of formula (I) in mixture (b), and wherein the method further comprises:

(III) adding starter compound to mixture (b) to form mixture (g), said starter compound being added in an amount sufficient to bring the molar ratio or weight ratio of starter compound to catalyst of formula (I) in mixture (g) to at least about 75% of said predetermined molar ratio or weight ratio, optionally wherein step (III) is repeated.

The method may be continuous, wherein there is a predetermined molar ratio or weight ratio of carbon dioxide to catalyst of formula (I) in mixture (b), and wherein the method further comprises:

(III) adding carbon dioxide to mixture (b) to form mixture (g), said carbon dioxide being added in an amount sufficient to bring the molar ratio or weight ratio of carbon dioxide to catalyst of formula (I) in mixture (g) to at least about 75% of said predetermined molar ratio or weight ratio, optionally wherein step (III) is repeated.

Step (III) may be conducted such that the molar ratio or weight ratio of epoxide, starter compound, carbon dioxide and/or solvent to catalyst of formula (I) in the mixture (g) does not fall below about 75% of said predetermined molar or weight ratio.

Step (III) may be conducted such that the molar ratios or weight ratios of epoxide, starter compound, carbon dioxide and solvent to catalyst of formula (I) in mixture (g) do not fall below about 75% of said predetermined molar or weight ratios. The method may be continuous, wherein there is a predetermined amount of catalyst of formula (I) in mixture (b), and wherein the method further comprises:

(III) adding catalyst of formula (I) to mixture (b) to form mixture (y), said catalyst of

formula (I) being added in an amount sufficient to bring the amount of catalyst of formula (I) in mixture (g) to about 50 to 550% of said predetermined amount, optionally wherein step (III) is repeated.

Step (III) may be conducted such that the amount of catalyst of formula (I) in the mixture (g) does not fall below about 50% of said predetermined amount.

The method may be continuous, wherein there is a predetermined amount of double metal cyanide (DMC) catalyst in mixture (b), and wherein the method further comprises:

(III) adding double metal cyanide (DMC) catalyst to mixture (b) to form mixture (g), said double metal cyanide (DMC) catalyst being added in an amount sufficient to bring the amount of double metal cyanide (DMC) catalyst in mixture (g) to about 50 to 550% of said predetermined amount, optionally wherein step (III) is repeated.

Step (III) may be conducted such that the amount of double metal cyanide (DMC) catalyst in mixture (g) does not fall below about 50% of said predetermined amount.

The rate at which the materials are added may be selected such that the temperature of the (exothermic) reaction does not exceed a selected temperature (i.e. that the materials are added slowly enough to allow any excess heat to dissipate such that the temperature of the reaction remains approximately constant).

In instances where addition of materials (i.e. per step III) are repeated, the addition may be repeated one, two, three, four, five, six, seven, eight, nine, ten or more times.

In mixture (a), the amount of said catalyst of formula (I) and the amount of said double metal cyanide (DMC) catalyst may be at a predetermined weight ratio of from about 300:1 to about 1 :100 to one another, for example, from about 120:1 to about 1 :75, such as from about 40:1 to about 1 :50, e.g. from about 30:1 to about 1 :30 such as from about 20:1 to about 1 :1 , for example from about 10:1 to about 2:1 , e.g. from about 5:1 to about 1 :5.

In step (I), said double metal cyanide (DMC) catalyst may be dry-mixed with the other components. In step (I), said double metal cyanide (DMC) catalyst may be mixed as a slurry, said slurry comprising the double metal cyanide (DMC) catalyst and the starter compound and/or solvent.

In step (I), said catalyst of formula (I) may be dry-mixed with the other components.

In step (I), said catalyst of formula (I) may be mixed as a solution, said solution comprising the catalyst of formula (I) and one or more of the starter compound, epoxide and/or a solvent.

Epoxide may be added in step (II).

Catalyst of formula (I) may be added in step (II).

Double metal cyanide (DMC) catalyst may be added in step (II).

Starter compound may be added in step (II).

Both epoxide and starter compound may be added in step (II).

Epoxide, catalyst of formula (I), double metal cyanide (DMC) catalyst and/or starter compound may be, independently, continuously added in step (II).

Epoxide, catalyst of formula (I), double metal cyanide (DMC) catalyst and/or starter compound may be, independently, discontinuously added in step (II).

Carbon dioxide may be provided continuously.

The method may be carried out at a pressure of between about 1 bar and about 60 bar carbon dioxide, optionally about 1 bar and about 40 bar, optionally about 1 bar and about 20 bar, optionally between about 1 bar and about 15 bar, optionally about 1 bar and about 10 bar, optionally about 1 bar and about 5 bar.

The temperature of the reaction may increase during the course of the method.

The starter compound which may be used in the methods for forming polycarbonate ether polyols comprises at least two groups selected from a hydroxyl group (-OH), a thiol (-SH), an amine having at least one N-H bond (-NHR’), a group having at least one P-OH bond (e.g. -PR’(O)0H, PR’(O)(0H)₂ or -P(O)(OR’)(OH)), or a carboxylic acid group (-C(O)OH).

Thus, the starter compound which may be used in the methods for forming polycarbonate ether polyols may be of the formula (III):

Z-( R^z)_a (III)

Z can be any group which can have 2 or more -R^z groups attached to it. Thus, Z may be selected from optionally substituted alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, cycloalkylene, cycloalkenylene, hererocycloalkylene, heterocycloalkenylene, arylene, heteroarylene, or Z may be a combination of any of these groups, for example Z may be an alkylarylene, heteroalkylarylene, heteroalkyl heteroarylene or alkylheteroarylene group. Optionally Z is alkylene, heteroalkylene, arylene, or

heteroarylene.

It will be appreciated that a is an integer which is at least 2, optionally a is in the range of between 2 and 8, optionally a is in the range of between 2 and 6.

Each R^z may be -OH, -NHR’, -SH, -C(O)0H, -P(O)(OR’)(OH), -PR’(O)(0H)₂ or -PR’(O)OH, optionally R^z is selected from -OH, -NHR’ or -C(O)0H, optionally each R^z is -OH, -C(O)0H or a combination thereof (e.g. each R^z is -OH).

R’ may be H, or optionally substituted alkyl, heteroalkyl, aryl, heteroaryl, cycloalkyl or heterocycloalkyl, optionally R’ is H or optionally substituted alkyl.

There may be two starter compounds in mixture (b), wherein the starter compound in step (I) is a first starter compound, and wherein step (II) comprises:

(A) adding one or more of first starter compound, epoxide, carbon dioxide,

catalyst of formula (I), double metal cyanide (DMC) catalyst and/or solvent to mixture (a); and

(B) adding a second starter compound and optionally epoxide, carbon dioxide, catalyst of formula (I), double metal cyanide (DMC) catalyst and/or solvent to form mixture (b) comprising first starter compound, second starter compound, epoxide, carbon dioxide, catalyst of formula (I), double metal cyanide (DMC) catalyst and optionally solvent. Step (B) may be conducted at least about 1 minutes after step (A), optionally at least about 5 minutes, optionally at least about 15 minutes, optionally at least about 30 minutes, optionally at least about 1 hour, optionally at least about 2 hours, optionally at least about 5 hours.

Said first starter compound may have a molecular weight of at least about 200 Da and said second starter compound may have a molecular weight of at most about 200 Da.

Said second starter compound may be polypropylene glycol having a molecular weight of about 200 to 1000 Da, optionally about 300 to 700 Da, optionally about 400 Da.

The or each starter compound has two or more hydroxyl groups, optionally three or more, optionally four or more, optionally five or more, optionally six or more, optionally seven or more, optionally eight or more hydroxyl groups.

It will be appreciated that any of the above features may be combined. For example, a may be between 2 and 8, each R^z may be -OH, -C(O)OH or a combination thereof, and Z may be selected from alkylene, heteroalkylene, arylene, or heteroarylene.

Exemplary starter compounds include diols such as 1 ,2-ethanediol (ethylene glycol), 1 ,2- propanediol, 1 ,3-propanediol (propylene glycol), 1 ,2-butanediol, 1 ,3-butanediol, 1 ,4- butanediol, 1 ,5-pentanediol, 1 ,6-hexanediol, 1 ,8-octanediol, 1 ,10-decanediol, 1 ,4- cyclohexanediol, 1 ,2-diphenol, 1 ,3-diphenol, 1 ,4-diphenol, neopentyl glycol, catechol, cyclohexenediol, 1 ,4-cyclohexanedimethanol, dipropylene glycol, diethylene glycol, tripropylene glycol, triethylene glycol, tetraethylene glycol, polypropylene glycols (PPGs) or polyethylene glycols (PEGs) having an Mn of up to about 1500g/mol, such as PPG 425,

PPG 725, PPG 1000 and the like, triols such as glycerol, benzenetriol, 1 ,2,4-butanetriol,

1 ,2,6-hexanetriol, tris(methylalcohol)propane, tris(methylalcohol)ethane,

tris(methylalcohol)nitropropane, trimethylol propane, polypropylene oxide triols and polyester triols, tetraols such as calix[4]arene, 2, 2-bis(methylalcohol)-1 , 3-propanediol, erythritol, pentaerythritol or polyalkylene glycols (PEGs or PPGs) having 4-OH groups, polyols, such as sorbitol or polyalkylene glycols (PEGs or PPGs) having 5 or more -OH groups, or compounds having mixed functional groups including ethanolamine, diethanolamine, methyldiethanolamine, and phenyldiethanolamine.

For example, the starter compound may be a diol such as 1 ,2-ethanediol (ethylene glycol),

1 -2-propanediol, 1 ,3-propanediol (propylene glycol), 1 ,2-butanediol, 1-3-butanediol, 1 ,4- butanediol, 1 ,5-pentanediol, 1 ,6-hexanediol, 1 ,8-octanediol, 1 ,10-decanediol, 1 ,12- dodecanediol, 1 ,4-cyclohexanediol, 1 ,2-diphenol, 1 ,3-diphenol, 1 ,4-diphenol, neopentyl glycol, catechol, cyclohexenediol, 1 ,4-cyclohexanedimethanol, poly(caprolactone) diol, dipropylene glycol, diethylene glycol, tripropylene glycol, triethylene glycol, tetraethylene glycol, polypropylene glycols (PPGs) or polyethylene glycols (PEGs) having an Mn of up to about 1500g/mol, such as PPG 425, PPG 725, PPG 1000 and the like. It will be appreciated that the starter compound may be 1 ,6-hexanediol, 1 ,4-cyclohexanedimethanol, 1 ,12- dodecanediol, poly(caprolactone) diol, PPG 425, PPG 725, or PPG 1000.

Further exemplary starter compounds may include diacids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid or other compounds having mixed functional groups such as lactic acid, glycolic acid, 3-hydroxypropanoic acid, 4-hydroxybutanoic acid, 5- hydroxypentanoic acid.

The ratio of the starter compound, if present, to the catalyst of formula (I) may be in amounts of from about 1000:1 to about 1 :1 , for example, from about 750:1 to about 5:1 , such as from about 500:1 to about 10:1 , e.g. from about 250:1 to about 20:1 , or from about 125:1 to about 30:1 , or from about 50:1 to about 20:1. These ratios are molar ratios. These ratios are the ratios of the total amount of starter to the total amount of the catalyst of formula (I) used in the method. These ratios may be maintained during the course of addition of materials.

The starter may be pre-dried (for example with molecular sieves) to remove moisture. It will be understood that any of the above reaction conditions described may be combined. For example, the reaction may be carried out at 60 bar or less, such as about 30 bar or less, optionally 20 bar or less (e.g. 10 bar or less) and at a temperature in the range of from about 5°C to about 200°C, e.g. from about 10°C to about 150°C, such as from about 15°C to about 100°C, for example, from about 20°C to about 90°C. The method of the invention may be carried out at from about 45°C to about 90°C.

The methods of the invention are capable of preparing polycarbonate ether polyols, which can be used, for example, to prepare polyurethanes. In particular, the continuous and discontinuous methods of the present invention may provide polycarbonate ether polyols having a low polydispersity index (PDI).

The methods of the invention are capable of producing polycarbonate ether polyols in which the amount of ether and carbonate linkages can be controlled. Thus, the invention may provide a polycarbonate ether polyol which has n ether linkages and m carbonate linkages, wherein n and m are integers, and wherein m/(n+m) is from greater than zero to less than 1. It will therefore be appreciated that n ³ 1 and m ³ 1.

For example, the methods of the invention are capable of preparing polycarbonate ether polyols having a wide range of m/(n+m) values. It will be understood that m/(n+m) may be about 0.05, about 0.10, about 0.15, about 0.20, about 0.25, about 0.30, about 0.35, about 0.40, about 0.45, about 0.50, about 0.55, about 0.60, about 0.65, about 0.70, about 0.75, about 0.80, about 0.85, about 0.90, about 0.95, or within any range prepared from these specific values. For example, m/(n+m) may be from about 0.05 to about 0.95, from about 0.10 to about 0.90, from about 0.15 to about 0.85, from about 0.20 to about 0.80, or from about 0.25 to about 0.75, etc.

As set out above, the methods of the invention are capable of preparing polycarbonate ether polyols where m/(n+m) is from about 0.7 to about 0.95, e.g. from about 0.75 to about 0.95.

Thus, the methods of the invention make it possible to prepare polycarbonate ether polyols having a high proportion of carbonate linkages, e.g. m/(n+m) may be greater than about 0.50, such as from greater than about 0.55 to less than about 0.95, e.g. about 0.65 to about 0.90, e.g. about 0.75 to about 0.90.

For example, the polycarbonate ether polyols produced by the methods of the invention may have the following formula (IV):

It will be appreciated that the identity of Z and Z’ will depend on the nature of the starter compound, and that the identity of R^e1 and R^e2 will depend on the nature of the epoxide used to prepare the polycarbonate ether polyol m and n define the amount of the carbonate and ether linkages in the polycarbonate ether polyol. The skilled person will understand that in the polymers of formula (IV), the adjacent epoxide monomer units in the backbone may be head-to-tail linkages, head-to-head linkages or tail- to-tail linkages.

It will also be appreciated that formula (IV) does not require the carbonate links and the ether links to be present in two distinct“blocks” in each of the sections defined by“a”, but instead the carbonate and ether repeating units may be statistically distributed along the polymer backbone, or may be arranged so that the carbonate and ether linkages are not in two distinct blocks.

Thus, the polycarbonate ether polyol prepared by the methods of the invention (e.g. a polymer of formula (IV)) may be referred to as a random copolymer, a statistical copolymer, an alternating copolymer, or a periodic copolymer.

The skilled person will appreciate that the wt% of carbon dioxide incorporated into a polymer cannot be definitively used to determine the amount of carbonate linkages in the polymer backbone. For example, two polymers which incorporate the same wt% of carbon dioxide may have very different ratios of carbonate to ether linkages. This is because the“wt% incorporation” of carbon dioxide does not take into account the length and nature of the starter compound. For instance, if one polymer (Mn 2000 g/mol) is prepared using a starter with a molar mass of 100 g/mol, and another polymer (Mn also 2000 g/mol) is prepared using a starter having a molar mass of 500 g/mol, and both the resultant polymers have the same ratio of m/n then the wt% of carbon dioxide in the polymers will be different due to the differing proportion of the mass of the starter in the overall polymer molecular weight (Mn). For example, if m/(m+n) was 0.5, the two polyols described would have carbon dioxide contents of 26.1 wt% and 20.6 wt% respectively.

As highlighted above, the methods of the invention are capable of preparing polyols which have a wide range of carbonate to ether linkages (e.g. m/(n+m) can be from greater than zero to less than 1), which, when using propylene oxide, corresponds to incorporation of up to about 43 wt% carbon dioxide. This is surprising, as DMC catalysts which have previously been reported can generally only prepare polyols having a ratio of carbonate to ether linkages of up to 0.75, and these amounts can usually only be achieved at high pressures of carbon dioxide, such as 30 bar, more commonly 40 bar or above.

Furthermore, catalysts which are used to prepare polycarbonate polyols can typically achieve a ratio of carbonate to ether linkages of about 0.95 or above (usually about 0.98 or above), and thus also incorporate a high wt% of carbon dioxide. However, these catalysts are not capable of preparing polyols having a ratio of carbonate to ether linkages below 0.95. The carbon dioxide wt% can be moderated by changing the mass of the starter: the resultant polyols contain blocks of polycarbonate. For many applications this is not desirable, as polycarbonates produced from epoxides and carbon dioxide are less thermally stable than polyethers and block copolymers can have very different properties from random or statistical copolymers.

All other things being equal, polyethers have higher temperatures of degradation than polycarbonates produced from epoxides and carbon dioxide. Therefore, a polyol having a statistical or random distribution of ether and carbonate linkages will have a higher temperature of degradation than a polycarbonate polyol, or a polyol having blocks of carbonate linkages. Temperature of thermal degradation can be measured using thermal gravimetric analysis (TGA).

As set out above, the methods of the invention prepare random copolymers, statistical copolymers, alternating copolymers, or periodic copolymers. Thus, the carbonate linkages are not in a single block, thereby providing a polymer which has improved properties, such as improved thermal degradation, as compared to a polycarbonate polyol. The polymer prepared by the methods of the invention may be a random copolymer or a statistical copolymer.

The polycarbonate ether polyol prepared by the methods of the invention may be of formula (IV), in which n and m are integers of 1 or more, the sum of all m and n groups is from 4 to 200, and wherein m/(m+n) is in the range of from greater than zero to less than 1.00. As set out above, m/(n+m) may be from about 0.05, about 0.10, about 0.15, about 0.20, about 0.25, about 0.30, about 0.35, about 0.40, about 0.45, about 0.50, about 0.55, about 0.60, about 0.65, about 0.70, about 0.75, about 0.80, about 0.85, about 0.90, about 0.95, or within any range prepared from these specific values. For example, m/(n+m) may be from about 0.05 to about 0.95, from about 0.10 to about 0.90, from about 0.15 to about 0.85, from about 0.20 to about 0.80, or from about 0.25 to about 0.75, etc.

The skilled person will also appreciate that the polyol must contain at least one carbonate and at least one ether linkage. Therefore, it will be understood that the number of ether and carbonate linkages (n+m) in the polyol will be ³ a. The sum of n+m must be greater than or equal to“a”. Each R^e1 may be independently selected from H, halogen, hydroxyl, or optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, heteroalkyl or

heteroalkenyl. R^e1 may be selected from H or optionally substituted alkyl.

Each R^e2 may be independently selected from H, halogen, hydroxyl, or optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, heteroalkyl or

heteroalkenyl. R^e2 may be selected from H or optionally substituted alkyl.

It will also be appreciated that R^e1 and R^e2 may together form a saturated, partially unsaturated or unsaturated ring containing carbon and hydrogen atoms, and optionally one or more heteroatoms (e.g. O, N or S). For example, R^e1 and R^e2 may together form a 5 or six membered ring.

As set out above, the nature of R^e1 and R^e2 will depend on the epoxide used in the reaction.

If the epoxide is cyclohexene oxide (CHO), then R^e1 and R^e2 will together form a six- membered alkyl ring (e.g. a cyclohexyl ring). If the epoxide is ethylene oxide, then R^e1 and R^e2 will both be H. If the epoxide is propylene oxide, then R^e1 will be H and R^e2 will be methyl (or R^e1 will be methyl and R^e2 will be H, depending on how the epoxide is added into the polymer backbone). If the epoxide is butylene oxide, then R^e1 will be H and R^e2 will be ethyl (or vice versa). If the epoxide is styrene oxide, then R^e1 may be hydrogen, and R^e2 may be phenyl (or vice versa).

It will also be appreciated that if a mixture of epoxides is used, then each occurrence of R^e1 and/or R^e2 may not be the same, for example if a mixture of ethylene oxide and propylene oxide are used, R^e1 may be independently hydrogen or methyl, and R^e2 may be

independently hydrogen or methyl.

Thus, R^e1 and R^e2 may be independently selected from hydrogen, alkyl or aryl, or R^e1 and R^e2 may together form a cyclohexyl ring, R^e1 and R^e2 may be independently selected from hydrogen, methyl, ethyl or phenyl, or R^e1 and R^e2 may together form a cyclohexyl ring.

Z’ corresponds to R^z, except that a bond replaces the labile hydrogen atom. Therefore, the identity of each Z’ depends on the definition of R^z in the starter compound. Thus, it will be appreciated that each Z’ may be -0-, -NR’-, -S-, -C(O)0-, -P(O)(OR’)0-, -PR’(O)(0-)₂ or -PR’(O)0- (wherein R’ may be H, or optionally substituted alkyl, heteroalkyl, aryl, heteroaryl, cycloalkyl or heterocycloalkyl, optionally R’ is H or optionally substituted alkyl), optionally Z’ may be -C(O)0-, -NR’- or -0-, each Z’ may be -0-, -C(O)0- or a combination thereof, optionally each Z’ may be -0-.

Z also depends on the nature of the starter compound. Thus, Z may be selected from optionally substituted alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, cycloalkylene, cycloalkenylene, hererocycloalkylene,

heterocycloalkenylene, arylene, heteroarylene, or Z may be a combination of any of these groups, for example Z may be an alkylarylene, heteroalkylarylene, heteroalkylheteroarylene or alkylheteroarylene group. Optionally Z is alkylene, heteroalkylene, arylene, or

heteroarylene, e.g. alkylene or heteroalkylene. It will be appreciated that each of the above groups may be optionally substituted, e.g. by alkyl.

The variable a will also depend on the nature of the starter compound. The skilled person will appreciate that the value of a in formula (IV) will be the same as a in formula (III).

Therefore, for formula (IV), a is an integer of at least 2, optionally a is in the range of between 2 and 8, optionally a is in the range of between 2 and 6.

The skilled person will also appreciate that the value of a influences the shape of the polyol prepared by the method of the invention. For example, when a is 2, the polyol of formula (IV) may have the following structure:

where Z, Z’, m, n, R^e1 and R^e2 are as described above for formula (IV).

For example, when a is 3, the polyol of formula (IV) may have the following formula:

where Z, Z’, m, n, R^e1 and R^e2 are as described above for formula (IV).

The skilled person will understand that each of the above features may be combined. For example, R^e1 and R^e2 may be independently selected from hydrogen, alkyl or aryl, or R^e1 and R^e2 may together form a cyclohexyl ring, each Z’ may be -0-, -C(O)0- or a combination thereof (optionally each Z’ may be -0-), and Z may be optionally substituted alkylene, heteroalkylene, arylene, or heteroarylene, e.g. alkylene or heteroalkylene, and a may be between 2 and 8.

The polyols produced by the methods of the invention are optionally low molecular weight polyols. It will be appreciated that the nature of the epoxide used to prepare the

polycarbonate ether polyol will have an impact on the resulting molecular weight of the product. Thus, the upper limit of n+m is used herein to define“low molecular weight” polymers of the invention.

The methods of the invention can advantageously prepare a polycarbonate ether polyol having a narrow molecular weight distribution. In other words, the polycarbonate ether polyol may have a low polydispersity index (PDI). The PDI of a polymer is determined by dividing the weight average molecular weight (M_w) by the number average molecular weight (M_n) of a polymer, thereby indicating the distribution of the chain lengths in the polymer product. It will be appreciated that PDI becomes more important as the molecular weight of the polymer decreases, as the percent variation in the polymer chain lengths will be greater for a short chain polymer as compared to a long chain polymer, even if both polymers have the same PDI.

Optionally the polymers produced by the methods of the invention have a PDI of from about 1 to less than about 2, optionally from about 1 to less than about 1.75, such as from about 1 to less than about 1.5, from about 1 to less than about 1.3, from about 1 to less than about 1.2, and from about 1 to less than about 1.1.

The M_n and M_w, and hence the PDI of the polymers produced by the methods of the invention may be measured using Gel Permeation Chromatography (GPC). For example, the GPC may be measured using an Agilent 1260 Infinity GPC machine with two Agilent PLgel m-m mixed-E columns in series. The samples may be measured at room temperature (293K) in THF with a flow rate of 1 ml_/min against narrow polystyrene standards (e.g.

polystyrene low EasiVials supplied by Agilent Technologies with a range of Mn from 405 to 49,450 g/mol). Optionally, the samples may be measured against poly(ethylene glycol) standards, such as polyethylene glycol EasiVials supplied by Agilent Technologies.

Optionally, the polyether carbonate polyols produced by the methods of the invention may have a molecular weight in the range of from about 500 to about 6,000 Da, optionally from about 700 to about 5,000 Da or from about 500 to about 3,000 Da.

It will also be appreciated that the polyols prepared by the method of the invention may be used for further reactions, for example to prepare a polyurethane, for example by reacting a polyol composition comprising a polyol prepared by the method of the invention with a composition comprising a di- or polyisocyanate.

The present invention also relates to a method for preparing a high molecular weight polyether carbonate, the method comprising the steps of:

(I) (a) mixing catalyst of formula (I), double metal cyanide (DMC) catalyst and

(c) mixing epoxide, catalyst of formula (I) and carbon dioxide and optionally solvent to form mixture (a); or

(d) mixing catalyst of formula (I), double metal cyanide (DMC) catalyst and

optionally epoxide, carbon dioxide and/or solvent to form mixture (a); and

wherein the catalyst of formula (I) has the following structure:

wherein:

M is a metal cation represented by M-(L)_V’; is a multidentate ligand (e.g. it may be either (i) a tetradentate ligand, or (ii) two bidentate ligands);

(E)_m represents one or more activating groups attached to the ligand(s), where

is a linker group covalently bonded to the ligand, each E is an activating functional group; and m is an integer from 1 to 4 representing the number of E groups present on an individual linker group;

v is an integer from 0 to 4; and

v’ is an integer that satisfies the valency of M, or is such that the complex represented by formula (I) above has an overall neutral charge. For example, v’ may be 0, 1 or 2, e.g. v’ may be 1 or 2.

Advantages set out above with respect to the method for preparing a polycarbonate ether polyol, such as to control the polymerisation reaction through controlled addition of materials, apply equally to the method for preparing high molecular weight polyether carbonates.

It will be appreciated that the method of the invention can advantageously prepare a high molecular weight polyether carbonate having a large molecular weight distribution. In other words, the polyether carbonate may have a relatively high polydispersity index (PDI).

Mixture (a) formed by steps (l)(a) or (b) may be held at a temperature of between about 50 to 110°C prior to step (II), optionally between about 60 to 90°C.

Mixture (a) formed by steps (l)(c) or (d) may be held at a temperature of between about 0 to 120°C prior to step (II), optionally between about 40 to 100°C optionally between about 50 to 90°C.

Mixture (a) may be held for at least about 1 minute prior to step (II), optionally at least about 5 minutes, optionally at least about 15 minutes, optionally at least about 30 minutes, optionally at least about 1 hour, optionally at least about 2 hours, optionally at least about 5 hours. Mixture (a) formed by steps (l)(c) may be held for at least about 5 minutes prior to step (II), optionally at least about 15 minutes, optionally at least about 30 minutes, optionally at least about 1 hour, optionally at least about 2 hours, optionally at least about 3 hours, optionally at least about 4 hours, optionally at least about 8 hours, optionally at least about 16 hours.

Step (I) (a) may comprise firstly mixing catalyst of formula (I), double metal cyanide (DMC) catalyst and optionally carbon dioxide to form mixture (a’), and subsequently adding epoxide and optionally carbon dioxide to form mixture (a). Conducting the method in this way may be useful for pre-activating one or both catalysts, as previously described.

Subsequent to step (I) (c), step (II) may comprise mixing double metal cyanide (DMC) catalyst, epoxide, and optionally carbon dioxide and/or solvent to form a pre-activated mixture and adding the pre-activated mixture to mixture (a) to form mixture (b).

The pre-activated mixture may be held at a temperature of between about 50 to 110°C prior to adding, optionally between about 60 to 90°C.

The method may employ a total amount of epoxide, wherein about 1 to 95% of the total amount of epoxide is mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%. The method may employ a total amount of catalyst of formula (I), wherein about 1 to 100% of the total amount of catalyst of formula (I) is mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

The method may employ a total amount of double metal cyanide (DMC) catalyst, wherein about 1 to 100% of the total amount of double metal cyanide (DMC) catalyst is mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

The method may employ a total amount of carbon dioxide, wherein about 1 to 100% of the total amount of carbon dioxide is mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

The method may employ a total amount of solvent, and wherein about 1 to 100% of the total amount of solvent is mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

(III) adding epoxide to mixture (b) to form mixture (y), said epoxide being added at an amount sufficient to bring the molar ratio or weight ratio of epoxide to catalyst of formula (I) in mixture (g) to at least about 75% of said predetermined molar ratio, optionally wherein step (III) is repeated.

(III) adding carbon dioxide to mixture (b) to form mixture (g), said carbon dioxide being added in an amount sufficient to bring the molar ratio or weight ratio of carbon dioxide to catalyst of formula (I) in mixture (g) to at least about 75% of said predetermined molar ratio, optionally wherein step (III) is repeated.

The method may be continuous, wherein there is a predetermined molar ratio or weight ratio of solvent to catalyst of formula (I) in mixture (b), and wherein the method further comprises: (III) adding solvent to mixture (b) to form mixture (g), said solvent being added in an

amount sufficient to bring the molar ratio or weight ratio of solvent to catalyst of formula (I) in mixture (g) to at least about 75% of said predetermined molar ratio, optionally wherein step (III) is repeated.

Step (III) may be conducted such that the molar ratio or weight ratio of epoxide, carbon dioxide and/or solvent to catalyst of formula (I) in mixture (g) does not fall below about 75% of said predetermined molar ratio or weight ratio.

Step (III) may be conducted such that the molar ratios or weight ratios of epoxide, carbon dioxide and solvent to catalyst of formula (I) in mixture (g) do not fall below about 75% of said predetermined molar ratios or weight ratios.

The method may be continuous, wherein there is a predetermined amount of catalyst of formula (I) in mixture (b), and wherein the method further comprises:

(III) adding catalyst of formula (I) to mixture (b) to form mixture (g), said catalyst of

Step (III) may be conducted such that the amount of catalyst of formula (I) in the mixture (g) does not fall below about 50% of said predetermined amount. The method may be continuous, wherein there is a predetermined amount of double metal cyanide (DMC) catalyst in mixture (b), and wherein the method further comprises:

(III) adding double metal cyanide (DMC) catalyst to mixture (b) to form mixture (y), said double metal cyanide (DMC) catalyst being added in an amount sufficient to bring the amount of double metal cyanide (DMC) catalyst in mixture (g) to about 50 to 550% of said predetermined amount, optionally wherein step (III) is repeated.

In step (I), said double metal cyanide (DMC) catalyst may be dry-mixed with the other components.

In step (I), said double metal cyanide (DMC) catalyst may be mixed as a slurry, said slurry comprising the double metal cyanide (DMC) catalyst and solvent.

In step (I), said catalyst of formula (I) may be mixed as a solution, said solution comprising the catalyst of formula (I) and one or more of the epoxide and/or a solvent.

Epoxide may be added in step (II). Catalyst of formula (I) may be added in step (II).

Double metal cyanide (DMC) catalyst may be added in step (II).

Epoxide, catalyst of formula (I) and/or double metal cyanide (DMC) catalyst may be, independently, continuously added in step (II).

Epoxide, catalyst of formula (I) and/or double metal cyanide (DMC) catalyst may be, independently, discontinuously added in step (II).

Carbon dioxide may be provided continuously.

The temperature of the reaction may increase during the course of the method.

The method of the invention is capable of preparing polyether carbonates. The method of the invention is capable of producing polyether carbonates in which the amount of ether and carbonate linkages can be controlled. Thus, the invention provides a polyether carbonate which has n ether linkages and m carbonate linkages, wherein n and m are integers, and wherein m/(n+m) is from greater than zero to less than 1.

For example, the method of the invention is capable of preparing polyether carbonates having a wide range of m/(n+m) values. It will be understood that m/(n+m) may be about 0.05, about 0.10, about 0.15, about 0.20, about 0.25, about 0.30, about 0.35, about 0.40, about 0.45, about 0.50, about 0.55, about 0.60, about 0.65, about 0.70, about 0.75, about 0.80, about 0.85, about 0.90, about 0.95, or within any range prepared from these specific values. For example, m/(n+m) may be from about 0.05 to about 0.95, from about 0.10 to about 0.90, from about 0.15 to about 0.85, from about 0.20 to about 0.80, or from about 0.25 to about 0.75, etc.

Thus, the method of the invention makes it possible to prepare polyether carbonates having a high proportion of carbonate linkages, e.g. m/(n+m) may be greater than about 0.50, such as from greater than about 0.55 to less than about 0.95, e.g. about 0.65 to about 0.90, e.g. about 0.75 to about 0.90. The method of the invention is able to prepare polymers having a high ratio of m/(n+m) under mild conditions, for example, under pressures of about 20 bar or below, such as 10 bar or below.

For example, the polyether carbonates produced by the method of the invention may have the following formula (IV):

It will be appreciated that the identity of X^a will depend on the nature of L or E in the compound of formula (I), and that the identity of R^e1 and R^e2 will depend on the nature of the epoxide used to prepare the polyether carbonate “m” and“n” define the amount of the carbonate and ether linkages in the polyether carbonate. It will be appreciated that n £ 1 and m £ 1.

It will be understood that X^a may not be a group containing -OH.

The skilled person will understand that in the polymers of formula (IV), the adjacent epoxide monomer units in the backbone may be head-to-tail linkages, head-to-head linkages or tail- to-tail linkages.

It will also be appreciated that formula (IV) does not require the carbonate links and the ether links to be present in two distinct“blocks” in each of the sections defined by“m” and“n”, but instead the carbonate and ether repeating units may be statistically distributed along the polymer backbone, or may be arranged so that the carbonate and ether linkages are not in two distinct blocks.

Thus, the polyether carbonate prepared by the method of the invention (e.g. a polymer of formula (IV)) may be referred to as a random copolymer, a statistical copolymer, an alternating copolymer, or a periodic copolymer. The skilled person will appreciate that the wt% of carbon dioxide incorporated into a polymer will be directly proportional to the number of carbonate linkages in the polymer backbone.

All other things being equal, polyethers have higher temperatures of degradation than polycarbonates produced from epoxides and carbon dioxide. Therefore, a polyether carbonate having a statistical or random distribution of ether and carbonate linkages will have a higher temperature of degradation than a polycarbonate, or a polyether carbonate having blocks of carbonate linkages. Temperature of thermal degradation can be measured using thermal gravimetric analysis (TGA).

As set out above, the method of the invention prepares a random copolymer, a statistical copolymer, an alternating copolymer, or a periodic copolymer. Thus, the carbonate linkages are not in a single block, thereby providing a polymer which has improved properties, such as improved thermal degradation, as compared to a polycarbonate. Optionally, the polyether carbonate prepared by the method of the invention is a random copolymer or a statistical copolymer.

The polyether carbonate prepared by the method of the invention may be of formula (IV), in which n and m are integers of 1 or more, the sum of all m and n groups is from 4 to 200, and wherein m/(m+n) is in the range of from greater than zero to less than 1.00. As set out above, m/(n+m) may be from about 0.05, about 0.10, about 0.15, about 0.20, about 0.25, about 0.30, about 0.35, about 0.40, about 0.45, about 0.50, about 0.55, about 0.60, about 0.65, about 0.70, about 0.75, about 0.80, about 0.85, about 0.90, about 0.95, or within any range prepared from these specific values. For example, m/(n+m) may be from about 0.05 to about 0.95, from about 0.10 to about 0.90, from about 0.15 to about 0.85, from about 0.20 to about 0.80, or from about 0.25 to about 0.75, etc.

The skilled person will also appreciate that the polyether carbonate must contain at least one carbonate and at least one ether linkage e.g. n ³ 1 and m ³ 1. Therefore, it will be understood that the number of ether and carbonate linkages (n+m) in the polyether carbonate will define the molecular weight of the polymer. For example, optionally n ³ 5 and m ³ 5, or n ³ 10 and m ³ 10, or n ³ 20 and m ³ 20, or n ³ 50 and m ³ 50.

Optionally, m + n ³ 10, or m+ n ³ 20, or m + n ³ 100, or m + n ³ 200, or m + n ³ 500, or m + n ³ 1 ,000. Each R^e1 may be independently selected from H, halogen, hydroxyl, or optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, heteroalkyl or

heteroalkenyl. Optionally R^e1 may be selected from H or optionally substituted alkyl.

heteroalkenyl. Optionally R^e2 may be selected from H or optionally substituted alkyl.

It will also be appreciated that R^e1 and R^e2 may together form a saturated, partially unsaturated or unsaturated ring containing carbon and hydrogen atoms, and optionally one or more heteroatoms (e.g. O, N or S). For example, R^e1 and R^e2 may together form a 5 or 6 membered ring.

As set out above, the nature of R^e1 and R^e2 will depend on the epoxide used in the reaction. If the epoxide is cyclohexene oxide (CHO), then R^e1 and R^e2 will together form a six- membered alkyl ring (e.g. a cyclohexyl ring). If the epoxide is ethylene oxide, then R^e1 and R^e2 will both be H. If the epoxide is propylene oxide, then R^e1 will be H and R^e2 will be methyl (or R^e1 will be methyl and R^e2 will be H, depending on how the epoxide is added into the polymer backbone). If the epoxide is butylene oxide, then R^e1 will be H and R^e2 will be ethyl (or vice versa). If the epoxide is styrene oxide, then R^e1 may be hydrogen, and R^e2 may be phenyl (or vice versa).

independently hydrogen or methyl.

Thus, R^e1 and R^e2 may be independently selected from hydrogen, alkyl or aryl, or R^e1 and R^e2 may together form a cyclohexyl ring, optionally R^e1 and R^e2 may be independently selected from hydrogen, methyl, ethyl or phenyl, or R^e1 and R^e2 may together form a cyclohexyl ring.

As set out above, the nature of X^a depends on the nature of the group E or L used in the compound of formula (I), and in particular on the group E or L, or component part of E that is capable of ring opening the epoxide. Thus, if L is an anionic ligand that is capable of ring-opening an epoxide, X^a may be directly derived from L and may be selected from 0C(O)R_x, OSO2R_X, OSOR_x, OSO(R_x)2, S(O)R_x, OR_x, acyl, phosphinate, halide, nitrate, hydroxyl, carbonate, amino, amido or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl, where R_x is independently hydrogen, or optionally substituted aliphatic, haloaliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl, alkylaryl or heteroaryl.

Optionally X^a is independently 0C(O)R_x, OSO₂R_X, 0S(O)R_x, OSO(R_x)2, S(O)R_x, OR_x, acyl halide, nitrate, hydroxyl, carbonate, amino, nitro, amido, alkyl (e.g. branched alkyl), heteroalkyl, (for example silyl), aryl or heteroaryl. Optionally, each X^a is independently 0C(O)R_x, OR_x, halide, carbonate, amino, nitro, alkyl, aryl, heteroaryl, phosphinate or OSO₂R_x. Optional substituents for when X^a is aliphatic, heteroaliphatic, alicyclic,

heteroalicyclic, aryl or heteroaryl include halogen, hydroxyl, nitro, cyano, amino, or substituted or unsubstituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl.

Exemplary options for X^a include OAc, 0C(O)CF₃, lactate, 3-hydroxypropanoate, halogen, NOs, OSO(CH₃)₂, Et, Me, OMe, O'Pr, 0*Bu, Cl, Br, I, F, N(*RG)2 or N(SiMe₃)₂, OPh, OBn, salicylate, dioctyl phosphinate, etc.

Optionally, R_x is alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, cycloalkyl, or alkylaryl. Optional substituents for R_x include halogen, hydroxyl, cyano, nitro, amino, alkoxy, alkylthio, or substituted or unsubstituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl (e.g. optionally substituted alkyl, aryl, or heteroaryl).

Optionally X^a is selected from 0C(O)R_x, OR_x, halide, carbonate, amino, nitro, alkyl, aryl, heteroaryl, phosphinate or OSO₂R_X, R_x is alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl or alkylaryl. Optionally each X^a is the same and is 0C(O)R_x, OR_x, halide, alkyl, aryl, heteroaryl, phosphinate or OSO₂R_X. Optionally X^a is 0C(O)R_x. Optionally still X^a is selected from OAc, O₂CCF₃, or O₂C(CH₂)₃Cy. Optionally X^a is OAc.

Optionally each R_x is the same and is selected from an optionally substituted alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, cycloalkyl or alkylaryl. Optionally each R_x is the same and is an optionally substituted alkyl, alkenyl, heteroalkyl, aryl, heteroaryl, cycloalkyl or alkylaryl. Optionally each R_x is the same and is an optionally substituted alkyl, alkenyl, heteroalkyl; or cycloalkyl. Optionally still R_x is an optionally substituted alkyl, heteroalkyl or cycloalkyl. Optionally R_x is an optionally substituted alkyl. As discussed below in relation to catalysts of formula (I), if L is not capable of ring opening an epoxide, the metal complex will contain at least one functional group that is capable of ring opening an epoxide. For example, at least one E group will be present. Therefore, if the activating group E is present in the compound of formula (I) and is capable of ring opening the epoxide, X^a may be selected from neutral activating groups including nitrogen-containing functional groups, phosphorus-containing functional groups, mixed phosphorus and nitrogen-containing functional groups, sulphur-containing functional groups, arsenic- containing functional groups or any anions present as counterions to cationic E groups.

If E comprises an anion (C-) as a counterion, X^a may depend on the nature of X-.

Thus, X^a may be any suitable anion. X^a may be a nucleophilic or non-nucleophilic anion. Exemplary nucleophilic anions include, but are not limited to, -OR^a, -SR^a, -O(C=O)R^a, - 0(C=O)OR^a, -O(C=O)N(R^a)₂, -N(R^a)(C=O)R^a, -NC, -CN, -Br, -I, -Cl, -N₃, -O(S0₂)R^a and - OPR^a3, wherein each R^a is independently selected from H, optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aryl and optionally substituted heteroaryl. Exemplary non-nucleophilic anions include, but are not limited to, BF₄- and CF3SO3-.

It will be appreciated that optional definitions for X^a and optional definitions for R_x and R^a may be combined. For example, each X^a may be independently 0C(O)R_x or 0(C=O)R^a, OSO₂R_X or 0(S0₂)R^a, 0S(O)R_x, OSO(R_x)₂, S(O)R_x, OR_x or OR^a, SR^a, -O(C=O)N(R^a)₂, acyl, halide, -NC, -CN, -N3, nitrate, hydroxyl, carbonate, amino, nitro, amido, alkyl (e.g. branched alkyl), heteroalkyl, (for example silyl), aryl or heteroaryl, -OPR^a3, e.g. each may be independently OC(O)R_xor 0(C=O)R^a, OR_xor OR^a, halide, carbonate, amino, nitro, alkyl, aryl, heteroaryl, phosphinate or OS0₂R_xor 0(S0₂)R^a, and R_x may be hydrogen, optionally substituted alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, cycloalkyl, or alkylaryl and each R^a is independently selected from H, optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aryl and optionally substituted heteroaryl.

The skilled person will understand that each of the above features may be combined. For example, R^e1 and R^e2 may be independently selected from hydrogen, alkyl or aryl, or R^e1 and R^e2 may together form a cyclohexyl ring, X^a may be optionally substituted aliphatic or heteroaliphatic, e.g. alkylene or heteroalkylene. The polyether carbonates produced by the method of the invention are optionally high molecular weight polyether carbonates. It will be appreciated that the nature of the epoxide used to prepare the polyether carbonate will have an impact on the resulting molecular weight of the product. Thus, the lower limit of n+m is used herein to define“high molecular weight” polymers of the invention.

Optionally, the polyether carbonates produced by the method of the invention may have a molecular weight of at least about 25,000 Daltons, such as at least about 40,000 Daltons, e.g. at least about 50,000 Daltons, or at least about 100,000 Daltons, such as between about 50,000 Daltons and 1 ,000,000 Daltons. High molecular weight polymers formed by the method of the present invention typically have molecular weights above about 100,000 Daltons, such as at least about 500,000 Daltons, optionally at least about 1 ,000,000 Daltons.

The method of the invention can advantageously prepare a polyether carbonate having a large molecular weight distribution. In other words, the polyether carbonate may have a relatively high polydispersity index (PDI). The PDI of a polymer is determined by dividing the weight average molecular weight (M_w) by the number average molecular weight (M_n) of a polymer, thereby indicating the distribution of the chain lengths in the polymer product. For high molecular weight polymers, a large PDI can be desirable as the short chains act as plasticisers for the longer chains, thereby preventing the polymer from becoming too brittle.

Optionally the polymers produced by the method of the invention have a PDI of greater than about 1 , optionally greater than about 2, optionally greater than about 3.

The M_n and M_w, and hence the PDI of the polymers produced by the method of the invention may be measured using Gel Permeation Chromatography (GPC). For example, the GPC may be measured using an Agilent 1260 Infinity GPC machine with two Agilent PLgel m-m mixed-E columns in series. The samples may be measured at room temperature (293K) in THF with a flow rate of 1 ml_/min against narrow polystyrene standards (e.g. polystyrene low EasiVials supplied by Agilent Technologies with a range of Mn from 405 to 49,450 g/mol). Optionally, the samples may be measured against poly(ethylene glycol) standards, such as polyethylene glycol EasiVials supplied by Agilent Technologies. Features common to both the method for preparing a polycarbonate ether polyol and the method for preparing high molecular weight polyether carbonate are set out below.

The methods of the present invention may be carried out in the presence of a solvent, however it will also be appreciated that the methods may be carried out in the absence of a solvent. When a solvent is present, it may be toluene, hexane, t-butyl acetate, diethyl carbonate, dimethyl carbonate, dioxane, dichlorobenzene, methylene chloride, propylene carbonate, ethylene carbonate, acetone, ethyl acetate, propyl acetate, n-butyl acetate, tetrahydrofuran (THF), etc. The solvent may be toluene, hexane, acetone, ethyl acetate and n-butyl acetate.

The solvent may act to dissolve one or more of the materials. However, the solvent may also act as a carrier, and be used to suspend one or more of the materials in a suspension. Solvent may be required to aid addition of one or more of the materials during the steps of the methods of the present invention.

The epoxide which is used in the methods may be any suitable compound containing an epoxide moiety. Exemplary epoxides include ethylene oxide, propylene oxide, butylene oxide and cyclohexene oxide.

The epoxide may be purified (for example by distillation, such as over calcium hydride) prior to reaction with carbon dioxide. For example, the epoxide may be distilled prior to being added.

The methods of the present invention can be carried out on any scale. The method may be carried out on an industrial scale. As will be understood by the skilled person, catalytic reactions often involve the generation of heat (i.e. catalytic reactions are generally exothermic). The generation of heat during a small-scale reaction is unlikely to be problematic, as any increase in temperature can be controlled relatively easily by, for example, the use of an ice bath. With larger scale reactions, and particularly industrial scale reactions, the generation of heat during a reaction can be problematic and potentially dangerous. Thus, the gradual addition of materials as described herein may allow the rate of the catalytic reaction to be controlled and can minimise the build-up of excess heat. The rate of the reaction may be controlled, for example, by adjusting the flow rate of the materials during addition. Thus, the methods of the present invention have particular advantages if applied to large, industrial scale catalytic reactions. The temperature may increase during the course of the methods of the invention. For example, the methods may be initiated at a low temperature (e.g. at a temperate of about 50°C to 80°C or less) and reaction mixture may be allowed to increase in temperature during the course of the methods. For example, the temperature of the reaction mixture increases during the course of the method of the invention from about 50°C at the start of the reaction to about 80°C at the end of the reaction. This increase in temperature may be gradual, or may be rapid. This increase in temperature may be a result of applying external heating sources, or may be achieved via an exothermic reaction, as described above.

The temperature of the reaction mixture may decrease during the course of the methods of the invention. For example, the methods may be initiated at a high temperature (e.g. at a temperate of about 90-150°C and the reaction mixture may be cooled during the course of the methods (e.g. at a temperate of about 50°C to 80°C or less). This decrease in temperature may be gradual, or may be rapid. This decrease in temperature may be a result of applying external cooling sources, as described above.

The present invention also relates to a product obtainable by the methods discussed above.

The catalyst of formula (I) has the following structure:

wherein:

M is a metal cation represented by M-(L)_V’;

(E)_m represents one or more activating groups attached to the ligand(s), where

L is a coordinating ligand, for example, L may be a neutral ligand, or an anionic ligand that is capable of ring-opening an epoxide; v is an integer from 0 to 4; and

v’ is an integer that satisfies the valency of M, or is such that the complex represented by formula (I) above has an overall neutral charge. For example, v’ may be 0, 1 or 2, e.g. v’ may be 1 or 2. If v’ is 0 or if v’ is a positive integer and each L is a neutral ligand which is not capable of ring opening an epoxide, v is an integer from 1 to 4.

As indicated above, the present invention provides a method for reacting an epoxide with carbon dioxide in the presence of a catalyst of formula (I), a double metal cyanide (DMC) catalyst, and a starter compound. The catalyst of formula (I) therefore contains at least one functional group that is capable of ring opening an epoxide.

The location of the functional group that is capable of ring opening an epoxide is not fixed in the catalyst of formula (I). As such, the coordinating ligand L and/or activating group E (which is tethered to the multidentate ligand) can be capable of ring opening an epoxide. It is important, however, that at least one of E or L is capable of ring opening an epoxide.

Thus, when v is 0 (and therefore an E group is absent), at least one anionic L is a ligand that is capable of ring opening an epoxide, and v’ is a positive integer. Alternatively, if v’ is a positive integer and each L is a neutral ligand that is not capable of ring opening an epoxide, then an E group that is capable of ring opening an epoxide is present, and v is a positive integer. In other words, if v’ is 0, or if v’ is a positive integer and each L is a neutral ligand, then v is an integer from 1 to 4.

M can be any metal. However, it is preferred that M is selected from Mg, Ca, Zn, Ti, Cr, Mn, V, Fe, Co, Mo, W, Ru, Al, and Ni. Preferably, M is selected from Mg, Ca, Zn, Ti, Cr, Mn, Fe, Co, Al and Ni. More preferably, M is selected from Cr, Co, Al, Fe and Mn. Even more preferably, M is selected from Cr, Co, Al and Mn. Most preferably, M is selected from Al, Cr, and Co. Thus, the catalyst of formula (I) is most preferably an aluminium, chromium or cobalt complex.

When M is a transition metal, multiple oxidation states of that metal may exist, and these may be used in the catalyst of formula (I). For example, if M is Cr, then M may be either Cr(ll) or Cr(lll).

Thus, the skilled person will understand that the metal M may be Mg(ll), Ca(ll), Zn(ll), Ti(ll), Ti(lll), Ti(IV), Cr(ll), Cr(lll), Mn(ll), Mn(lll), V(ll), V(lll), Fe(ll), Fe(lll), Co(ll), Co(lll), Mo(IV), Mo(VI), W(IV), W(VI), Ru(ll), Ru(lll), Al(lll), Ni(ll) and Ni(lll). The skilled person will understand that changing the oxidation state of the metal may require changes to be made to other substituent definitions in order to obtain a charge neutral catalyst of formula (I).

In formula (I)

is a multidentate ligand. Preferably,

is either (i) two bidentate ligands, or (ii) a tetradentate ligand.

Bidentate ligands are ligands that can co-ordinate with the metal centre in two places, but two bidentate ligands must be present to stabilise the metal centre in the catalyst of formula (I). The two bidentate ligands may be the same or may be different. A bidentate ligand suitable for use in the present invention is shown below:

Figure 1

Metal centres may have more than four co-ordination sites, with six co-ordination sites being common when the metal is a transition metal. Therefore, when two bidentate ligands are present, a further ligand may be present. For example, the further ligand (i.e. an anionic ligand L) may be present, e.g. to satisfy the valency of the metal centre or to ensure the neutrality of the overall complex.

For example, if M is a +2 metal cation (e.g. Mg²⁺), and a tetradentate or two bidentate ligands are present, a neutral ligand L may be present. However, in this case, this metal complex will contain at least one functional group that is capable of ring opening an epoxide, for example, at least one E group may be present (i.e. v may be an integer from 1 to 4). Alternatively, if M is a +2 metal cation (e.g. Mg²⁺), and a tetradentate or two bidentate ligands are present, an anionic ligand L may be present. In this instance, at least one group E may be positively charged, or a counter cation may be present, to ensure the overall neutrality of the complex. For example, the cation may be a tetraalkyl ammonium cation, a bis(triarylphosphine)iminium cation or a tetraalkylphosphonium cation.

If M is a +3 metal cation (e.g. Al³⁺), and a tetradentate or two bidentate ligands are present, an anionic L group may be present, e.g. to satisfy the valency of the metal centre. A further neutral L group may also be present. Alternatively, if M is a +3 metal cation (e.g. Al³⁺), and a tetradentate or two bidentate ligands are present, two anionic L groups may be present. In this instance, at least one group E may be positively charged, or a counter cation may be present, to ensure the overall neutrality of the complex. For example the cation may be a tetraalkyl ammonium cation, a bis(triarylphosphine)iminium cation or a tetraalkyl

phosphinium cation.

The arrangement of the bidentate ligands and the other coordinating ligand(s) is not fixed, and many different configurations can be adopted, as shown below:

wherein M is a metal centre as defined above, L is a coordinating ligand, and ^N O represents a bidentate ligand as shown in Figure 1 above.

In Figure 2 above, L may be replaced with an E group that is tethered to the bidentate ligand.

Tetradentate ligands are ligands that can co-ordinate with the metal centre in four places. Examples of tetradentate ligands that are suitable for use in the present invention include the following:

Figure 3 wherein M is the metal centre as defined above in formula (I) and Y is a linking atom or group, such as a carbon, oxygen or nitrogen atom, or an optionally substituted alkyl or alkenyl group.

Salen ligands and derivatives thereof are particularly preferred tetradentate ligands for use in the present invention. These are shown in Figure 3, see the first two structures on line 3 thereof. A further general salen ligand and preferred salen derivative ligands for use in the catalyst of formula (I) are shown in Figure 3a below:

salen derivatives

Figure 3a

Porphyrin ligands and derivatives thereof are also preferred tetradentate ligands for use in the present invention. These are shown in Figure 3, see the two structures on line 4 thereof. Particularly preferred porphyrin and porphyrin derivative ligands for use in the catalyst of formula (I) are shown in Figure 3b below:

Figure 3b

As indicated above, metal centres may have more than four co-ordination sites, with six co ordination sites being common when the metal centre is a transition metal. Therefore, the structures set out in Figures 3, 3a and 3b may also have one or more L ligands coordinated to the metal centre. The ligand L may be a neutral ligand, or the ligand L may be an anionic ligand which is capable of ring opening an epoxide. When the ligand L is an anion, it may, for example, be present to satisfy the valency of the metal centre or to ensure the overall neutrality of the metal complex.

The complexes set out in Figures 3, 3a and 3b may contain a neutral ligand L. It will be appreciated that the structures set out in Figures 3, 3a and 3b may contain a mixture of L ligands. In other words, each L may be the same or different. The structures set out in Figures 3, 3a and 3b may contain a mixture of a neutral L ligand, and an anionic ligand L which is capable of ring opening an epoxide. For example, one or more further neutral ligands L may also be present.

Therefore, it will be appreciated that if M is a +2 metal cation (e.g. Mg²⁺), a neutral ligand L may be present. In this case, if L is not capable of ring opening an epoxide, the metal complex will contain at least one functional group that is capable of ring opening an epoxide. For example, at least one E group will be present (i.e. v may be an integer from 1 to 4). Alternatively, if M is a +2 metal cation (e.g. Mg²⁺), and a tetradentate or two bidentate ligands are present, an anionic ligand L may be present. In this instance, at least one group E may be positively charged, or a counter cation may be present, to ensure the overall neutrality of the complex. For example, the cation may be a tetraalkyl ammonium cation, a bis(triarylphosphine)iminium cation or a tetraalkyl phosphinium cation.

If M is a +3 metal cation (e.g. Al³⁺), an anionic L group may be present to satisfy the valency of the metal centre. A further neutral L group may also be present. Alternatively, if M is a +3 metal cation (e.g. Al³⁺), and a tetradentate or two bidentate ligands are present, two anionic L groups may be present. In this instance, at least one group E may be positively charged, or a counter cation may be present, to ensure the overall neutrality of the complex. For example, the cation may be a tetraalkyl ammonium cation, a bis(triarylphosphine)iminium cation or a tetraalkyl phosphinium cation.

The skilled person will also appreciate that in Figures 2, 3, 3a and 3b, 1 to 4 groups represented by“ (E)_m” may also be present (i.e. if v is not 0). However, in Figures 2, 3,

3a and 3b, these groups have been omitted for clarity. As will be readily understood by the skilled person, each“— (E)_m” group may be attached at any position on the multidentate ligand(s). In other words, any of the hydrogen atoms in the above bidentate and tetradentate ligands in Figures 2, 3, 3a and 3b above, may be substituted by a group"— (E)_m”.

In Figures 2, 3, 3a and 3b above showing bidentate and tetradentate ligands, optional substituents have been omitted for clarity. However, as will be readily understood by the skilled person, any or all of the hydrogen atoms in the above bidentate and tetradentate ligands may be substituted by another atom or functional group, provided that that position is not already substituted by an activating functional group (E)_m”. Examples of suitable substituent groups include, but are not limited to, -OH, -CN, -NO2, -IM₃, Cl, Br, F, I, Ci-i2alkyl, C2-12 alkenyl, C2-12 alkynyl, C3-12 cycloalkyl, C2-12 heterocycloalkyl, Ce-ie aryl and C2-18 heteroaryl. For the first two porphyrin derivative ligands shown in Figure 3b above, the pendant phenyl rings on the porphyrin core can be substituted with OMe, OBu, NO2, Cl, Br,

F and I groups. If these substituents are present, then substitution in the para position relative to the site of attachment to the porphyrin core may be preferred.

L is a coordinating ligand. L may be a neutral ligand, or L may be an anionic ligand that is capable of ring-opening an epoxide. It will be appreciated that each coordinating ligand L may be the same or different.

L being an anionic ligand capable of ring opening an epoxide When L is an anionic ligand which is capable of ring opening an epoxide, it may preferably be independently selected from 0C(O)R_x, OSO2R_X, OSOR_x, OSO(R_x)2, S(O)R_x, OR_x, acyl, phosphinate, halide, nitro, nitrate, hydroxyl, carbonate, amino, amido or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl; wherein R_x is independently hydrogen, or optionally substituted aliphatic, haloaliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl, alkylaryl or heteroaryl.

Preferably L is independently 0C(O)R^x, OSC>2R^x, 0S(O)R^x, OSO(R^x)2, S(O)R^x, OR^x, halide, nitrate, hydroxyl, carbonate, amino, nitro, amido, alkyl (e.g. branched alkyl), heteroalkyl, (for example silyl), aryl or heteroaryl. Even more preferably, each L is independently 0C(O)R^x, OR^x, halide, carbonate, amino, nitro, nitrate, alkyl, aryl, heteroaryl, phosphinate or OSC>2R^x Preferred optional substituents for when L is aliphatic, heteroaliphatic, alicyclic,

heteroalicyclic, aryl or heteroaryl include halogen, hydroxyl, nitrate, cyano, amino, or substituted or unsubstituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl.

R^x is independently hydrogen, or optionally substituted aliphatic, haloaliphatic,

heteroaliphatic, alicyclic, heteroalicyclic, aryl, alkylaryl, or heteroaryl. Preferably, R^x is alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, cycloalkyl, or alkylaryl. Preferred optional substituents for R^x include halogen, hydroxyl, cyano, nitro, amino, alkoxy, alkylthio, or substituted or unsubstituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl (e.g. optionally substituted alkyl, aryl, or heteroaryl).

Exemplary options for L include OAc, 0C(O)CF₃, lactate, 3-hydroxypropanoate, halogen, NOs, OSO(CH₃)2, Et, Me, OMe, O'Pr, 0*Bu, Cl, Br, I, F, N(^jPr)₂ or N(SiMe₃)_2, OPh, OBn, salicylate and dioctyl phosphinate.

Preferably L is selected from 0C(O)R^x, OR^x, halide, carbonate, amino, nitro, alkyl, aryl, heteroaryl, phosphinate or OSC>2R^x, R^x is optionally substituted alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl or alkylaryl. More preferably L is 0C(O)R^x, OR^x, halide, alkyl, aryl, heteroaryl, phosphinate or OSO₂R^x Still more preferably L is NO3, halide, OC(O)R^xor OR^x. More preferably still, L is selected from OAc, O2CCF3, Cl, Br, or OPh. Most preferably,

L is Cl, OAc or O2CCF₃.

Preferably each R^x is the same and is selected from an optionally substituted alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, cycloalkyl or alkylaryl. More preferably each R^x is the same and is an optionally substituted alkyl, alkenyl, heteroalkyl, aryl, heteroaryl, cycloalkyl or alkylaryl. Still more preferably each R^x is the same and is an optionally substituted alkyl, alkenyl, heteroalkyl; or cycloalkyl. More preferably still R^x is an optionally substituted alkyl, heteroalkyl or cycloalkyl. Most preferably R^x is an optionally substituted alkyl.

It will be appreciated that preferred definitions for L and preferred definitions for R^x may be combined. For example, each L may be independently 0C(O)R^x, OSC>2R^x, 0S(O)R^x, OSC R^, S(O)R^x, OR^x, halide, nitrate, hydroxyl, carbonate, amino, nitro, amido, alkyl (e.g. branched alkyl), heteroalkyl, (for example silyl), aryl or heteroaryl, e.g. each may be independently 0C(O)R^x, OR^x, halide, carbonate, amino, nitro, alkyl, aryl, heteroaryl, phosphinate or OSC>2R^x, and R^x may be optionally substituted alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, cycloalkyl, or alkylaryl.

Preferably, L may be 0C(O)R^x and wherein R^x is optionally substituted alkyl, preferably wherein R^x is a Ci-e alkyl group optionally substituted with one or more -OH groups. For example, L may be 0C(O)CH₂CH₂(0H).

More preferably, L may be 0C(O)R^x and wherein R^x is methyl, ethyl, trifluoromethyl or trifluoroethyl. For example, L may be 0C(O)CH₃, 0C(O)CH₂CH₃, 0C(O)CF₃,

0C(O)CH₂CF₃. Most preferably, L is 0C(O)CH₃ or 0C(O)CF₃.

L being a neutral ligand

When L is a neutral ligand, it may be capable of donating a lone pair of electrons (i.e. a Lewis base). In certain embodiments, L may be a nitrogen-containing Lewis base.

Alternatively, when L is a neutral ligand, it may be independently selected from an optionally substituted heteroaliphatic group, an optionally substituted h ete roa I i cyclic group, an optionally substituted heteroaryl group and water. More preferably, L is independently selected from water, an alcohol (e.g. methanol), a substituted or unsubstituted heteroaryl (imidazole, methyl imidazole (for example, N-methyl imidazole), pyridine, 4- dimethylaminopyridine, pyrrole, pyrazole, etc), an ether (dimethyl ether, diethylether, cyclic ethers, etc), a thioether, a carbene, a phosphine, a phosphine oxide, a substituted or unsubstituted heteroalicyclic (morpholine, piperidine, tetrahydrofuran, tetrahydrothiophene, etc), an amine, an alkyl amine trimethylamine, triethylamine, etc), acetonitrile, an ester (ethyl acetate, etc), an acetamide (dimethylacetamide, etc), a sulfoxide (dimethylsulfoxide, etc) etc.

L may be selected from optionally substituted heteroaryl, optionally substituted

heteroaliphatic, optionally substituted heteroalicyclic, an ether, a thioether, a carbene, a phosphine, a phosphine oxide, an amine, an alkyl amine, acetonitrile, an ester, an acetamide or a sulfoxide. It will also be appreciated that L may be water; a heteroaryl or heteroalicyclic group which are optionally substituted by alkyl, alkenyl, alkynyl, alkoxy, halogen, hydroxyl, nitro or nitrile. For example, L may be selected from water; a heteroaryl optionally substituted by alkyl (e.g. methyl, ethyl etc), alkenyl or alkynyl.

Exemplary neutral L groups include water, methanol, pyridine, methylimidazole (for example N-methyl imidazole), dimethylaminopyridine (for example, 4-methylaminopyridine), 1 ,5,7- triazabicyclo[4.4.0]dec-5-ene (TBD), 7-methyl-1 ,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD) and 1 ,8-diazabicyclo[5.4.0]undec-7-ene (DBU).

It will be appreciated by the skilled person that some neutral L ligands may be capable of ring opening an epoxide. Exemplary neutral L ligands which are capable of ring opening an epoxide include methylimidazole (for example N-methyl imidazole), and

dimethylaminopyridine (for example, 4-methylaminopyridine).

The skilled person will appreciate that the catalyst of the invention may have more than one L ligand. If more than one L ligand is present, the complex may contain a mixture of neutral L ligands, and anionic L ligands which are capable of ring opening an epoxide, the identity of L will depend on the nature of the macrocyclic coordinating ligand, and the change of the metal M.

Linker groups

Linker groups“ ” as shown in formula (I) contain between 1 and 30 carbon atoms, and optionally one or more heteroatoms selected from nitrogen, oxygen, sulfur, silicon, boron and phosphorus. These heteroatoms may be incorporated into the linker“backbone”. For example, the linker may include ether linkages, carbonate linkages, ester linkages or amide linkages. Alternatively, heteroatoms may be present as optional substituents on the linker backbone as, for example, hydroxyl groups, oxo groups, azide groups etc.

The linker may further contain saturated and/or cyclic groups, such as alkene or alkyne groups, carbocyclic rings, including aryl and heteroaryl rings. Thus, the linker can comprise a large number of different functional groups, heteroatoms and be of any suitable length. It is, however, important that the linker is long enough to allow the one or more activating groups to be positioned near to the metal atom of the catalyst of formula (I). As such, steric considerations and the relative flexibility of the groups in the linker must be considered. For example, alkyne groups are generally not considered to be flexible, as they have 180° geometry. Therefore, an alkyne group alone would be an unsuitable linker for most ligands. However, an alkyne group may be present in a linker to add rigidity to, for example, an alkyl chain.

Preferred linkers include substituted or unsubstituted, branched or unbranched C1-30 alkyl groups, substituted or unsubstituted, branched or unbranched C2-30 alkene groups, substituted or unsubstituted, branched or unbranched C1-30 ether groups, substituted or unsubstituted aryl groups and substituted or unsubstituted heteroaryl groups.

Preferably, the metal complexes of formula (I) include a metal atom coordinated to either (i) a tetradentate ligand or (ii) two bidentate ligands and at least one activating group E tethered to the ligand via one or more linker groups Preferably, there are 1 to 4

activating groups E tethered to the ligand

via 1 to 4 linker groups

Activating groups E for use in the present invention include nitrogen-containing functional groups, phosphorous-containing functional groups, mixed phosphorous and nitrogen- containing functional groups, sulphur-containing functional groups, arsenic-containing functional groups and combinations of thereof.

Nitrogen-containing activating groups

As indicated above, activating groups E for use in the present invention can include nitrogen- containing compounds. The nitrogen atom in the nitrogen-containing activating group may be neutral or may be positively charged. As will be understood by the skilled person, if the nitrogen atom is charged, then a negatively charged counter ion must be present. This counter ion may be a separate atom or molecule (such as a Cl- ion), making the nitrogen- containing activating group a salt. Alternatively, the charge may be satisfied by a negative charge on another atom within the nitrogen-containing activating group.

An example of a neutral nitrogen-containing activating group is an amine group. An example of a charged nitrogen-containing activating group with a separate counter ion is an amine salt. An example of a charged nitrogen-containing activating group with an internal counter ion is an N-oxide.

Suitable nitrogen-containing activating groups for use in the present invention include

Figure 4 wherein each Ra is independently H ; optionally substituted C1-20 aliphatic; optionally substituted C1-20 heteroaliphatic; optionally substituted phenyl; optionally substituted 3- to 8- membered saturated or partially unsaturated monocyclic carbocycle; optionally substituted 7- 14 carbon saturated, partially unsaturated or aromatic polycyclic carbocycle; optionally substituted 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms

independently selected from O, N or S; optionally substituted 3- to 8- membered saturated or partially unsaturated heterocyclic ring having 1-3 heteroatoms independently selected from O, N or S; optionally substituted 6- to 12- membered polycyclic saturated or partially unsaturated heterocycle having 1-5 heteroatoms independently selected from O, N or S; or optionally substituted 8- to 10-membered bicyclic heteroaryl ring having 1-5 heteroatoms independently selected from O, N or S; and

wherein two or more Ra groups can be taken together with intervening atoms to form one or more optionally substituted rings optionally containing one or more additional heteroatoms; X- is an anion, and ring A is an optionally substituted 5- to 10-membered heteroaryl group.

As indicated above, X- can be any anion. X- may therefore be a nucleophilic or non- nucleophilic anion. Exemplary nucleophilic anions include, but are not limited to, -OR^a, -SR^a, -O(C=O)R^a, -O(C=O)OR^a, -O(C=O)N(R^a)₂, -N(R^a)(C=O)R^a, -NC, -CN, -Br, -I, -Cl, -N₃, - 0(S0₂)R^a and -OPR^a3, wherein each R^a is independently selected from H, optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aryl and optionally substituted heteroaryl. Exemplary non-nucleophilic anions include, but are not limited to, BF₄- and CF3SO3-.

The wavy line indicates where the nitrogen-containing activating group is attached to

the linker.

Other suitable nitrogen-containing activating groups for use in the present invention include:

Figure 5 wherein Ra, X- and A are as defined above;

Rd is hydrogen, hydroxyl, optionally substituted C1-20 aliphatic; each occurrence of Rs and Rc|) is independently H; optionally substituted C1 -20 aliphatic; optionally substituted C1 -20 heteroaliphatic; optionally substituted phenyl; optionally substituted 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; optionally substituted 7 to 14 carbon saturated, partially unsaturated or aromatic polycyclic carbocycle; optionally substituted 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from O, N or S; optionally substituted 3- to 8-membered saturated or partially unsaturated heterocyclic ring having 1-3 heteroatoms independently selected from O, N or S; optionally substituted 6- to 12-membered polycyclic saturated or partially unsaturated heterocycle having 1-5 heteroatoms independently selected from O, N or S; or optionally substituted 8- to 10-membered bicyclic heteroaryl ring having 1-5 heteroatoms independently selected from O, N or S; and

wherein an Rs or Rc|) group can be taken with an Ra group to form one or more optionally substituted rings;

Ry is H; a protecting group; optionally substituted C1 -20 acyl; optionally substituted C1 -20 aliphatic; optionally substituted C1 -20 heteroaliphatic; optionally substituted phenyl; optionally substituted 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; optionally substituted 7-14 carbon saturated, partially unsaturated or aromatic polycyclic carbocycle; optionally substituted 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from O, N or S; optionally substituted 3- to 8-membered saturated or partially unsaturated heterocyclic ring having 1-3 heteroatoms independently selected from O, N or S; optionally substituted 6- to 12-membered polycyclic saturated or partially unsaturated heterocycle having 1-5 heteroatoms independently selected from O, N or S; or optionally substituted 8- to 10-membered bicyclic heteroaryl ring having 1-5 heteroatoms independently selected from O, N or S; and each occurrence of RK is independently selected from the group consisting of: Cl, Br, F, I, -NO2, -CN, -SR^b, -S(O)R^b, -S(O)₂R^b, -NR^bC(O)R^b, -OC(O)R^b, -C0₂R^b, -NCO, -N₃, -ORy, -OC(O)N(R^b)₂, -N(R^b)₂, -NR^bC(O)R^b, -NR^bC(O)OR^b; optionally substituted C1 -20 aliphatic; optionally substituted C1 -20 heteroaliphatic; optionally substituted phenyl; optionally substituted 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; optionally substituted 7-14 carbon saturated, partially unsaturated or aromatic polycyclic carbocycle; optionally substituted 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from O, N or S; optionally substituted 3- to 8-membered saturated or partially unsaturated heterocyclic ring having 1-3 heteroatoms independently selected from O, N or S; optionally substituted 6- to 12-membered polycyclic saturated or partially unsaturated heterocycle having 1-5 heteroatoms independently selected from O, N or S; or optionally substituted 8- to 10-membered bicyclic heteroaryl ring having 1-5 heteroatoms independently selected from O, N or S; where each occurrence of R^b is independently -H; optionally substituted Ci-e aliphatic; optionally substituted 3- to 7- membered heterocyclic; optionally substituted phenyl; and optionally substituted 8- to 10- membered aryl; and

wherein two or more adjacent RK groups can be taken together to form an optionally substituted saturated, partially unsaturated, or aromatic 5- to 12-membered ring containing 0 to 4 heteroatoms.

Preferred nitrogen-containing activating groups are shown below:

wherein Ra and X- are as defined above.

Particularly preferred nitrogen-containing activating groups are those shown in Figure 5a, wherein Ra is independently selected from H; optionally substituted Ci-₆ aliphatic; optionally substituted Ci-₆ heteroaliphatic and optionally substituted - to 8-membered saturated or partially unsaturated monocyclic carbocycle; and

X is selected from -OR^a, -O(C=O)R^a, -O(C=O)OR^a, -O(C=O)N(R^a)₂, -N(R^a)(C=O)R^a, BF₄, -CN, -F, -Br, -I and -Cl, wherein each R^a is independently selected from H, optionally substituted Ci-₆ aliphatic, optionally substituted Ci-₆ heteroaliphatic, optionally substituted C₆- 12 aryl and optionally substituted C3-11 heteroaryl.

More preferred nitrogen-containing activating groups for use in the present invention are those shown in Figure 5a, wherein Ra is independently selected from H; optionally substituted Ci-e aliphatic; optionally substituted Ci-e heteroaliphatic and optionally substituted - to 8-membered saturated or partially unsaturated monocyclic carbocycle; and

X- is selected from -F, -Br, -I, -Cl, BF₄, OAc, O₂COCF₃, NO₃, OR^a and 0(C=O)R^a, wherein R^a is selected from H, optionally substituted Ci-e alkyl, optionally substituted Ci-e heteroalkyl, optionally substituted Ce-₁₂ aryl and optionally substituted C_3-11 heteroaryl.

Phosphorous-containing activating groups

Activating groups for use in the present invention may contain a phosphorous atom.

Phosphorous-containing groups for use in the present invention therefore include phosphonates and phosphites. Examples of suitable phosphorous-containing activating groups are shown in Figure 6 below:

Figure 6

wherein Ra, Rp and Ry and are as defined above.

It is noted that two Ry groups within the same phosphorus-containing activating groups may be taken together with intervening atoms to form an optionally substituted ring structure. Alternatively, an Ry group may be taken with an Ra or Rp group to form an optionally substituted ring.

Mixed nitrogen- and phosphorous-containing activating groups

Examples of mixed activating groups containing both N and P atoms are shown below:

wherein Ra, Ry and X- are as defined above.

Activating groups containing other heteroatoms

As indicated above, activating groups for use in the present invention may also include sulfur or arsenic atoms. Examples of such activating groups are provided below:

wherein each instance of Ra is the same or different and is as defined above, and wherein X- is as defined above.

It will be appreciated that when v is 0 (i.e. E is absent), the catalyst of the invention may be used in combination with a co-catalyst. The co-catalyst may be selected from ammonium salts, phosphonium salts, iminium salts, arsonium salts or nitrogen containing nucleophiles. Examples of suitable co-catalysts include tetraalkyl ammonium salts (e.g. a tetrabutyl ammonium salt), tetraalkyl phosphonium salts (e.g. a tetrabutyl phosphonium salt), bis(triarylphosphine)iminium salts (e.g. a bis(triphenylphosphine)iminium salt), or a nitrogen containing nucleophile (e.g. methylimidazole (such as N-methyl imidazole),

dimethylaminopyridine (for example, 4-methylaminopyridine), 1 ,5,7-triazabicyclo[4.4.0]dec-5- ene (TBD), 7-methyl-1 ,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD) or 1 ,8- diazabicyclo[5.4.0]undec-7-ene (DBU)).

When the co-catalyst is a salt, the counter anion may be any suitable anion. The anion may be selected from -OR^a, -SR^a, -O(C=O)R^a, -O(C=O)OR^a, -O(C=O)N(R^a)₂, -N(R^a)(C=O)R^a, - NC, -CN, -Br, -I, -Cl, -IM3, -O(SO₂)R^a and -OPR^a3, wherein each R^a is independently selected from H, optionally substituted aliphatic, optionally substituted heteroaliphatic, optionally substituted aryl and optionally substituted heteroaryl. Exemplary anions include -Br, -I, -Cl, and -O(C=O)R^a.

The catalysts of formula (I) described above are used together with a double metal cyanide (DMC) catalyst and a starter compound in the synthesis of polycarbonate ether polyols from epoxides and carbon dioxide. Preferred catalysts of formula (I) for use in the method of the present invention are listed below. As will be understood by the skilled person, these embodiments may be combined in any manner to give particularly preferred catalysts of formula (I).

Embodiment 1 : A catalyst of formula (I), in which M is selected from Mg, Ca, Zn, Ti, Cr, Mn, V, Fe, Co, Mo, W, Ru, Al, and Ni.

Embodiment 2: The catalyst of Embodiment 1 , in which M is selected from Cr, Co, Al, Fe and Mn.

Embodiment 3: The catalyst of Embodiment 2, in which M is selected from Cr, Co, Al and Mn.

Embodiment 4: The catalyst of Embodiment 3, in which M is selected from Al, Cr and Co. Embodiment 5: The catalyst of Embodiment 4, in which M is Cr.

Embodiment 6: The catalyst of Embodiment 4, in which M is Al.

Embodiment 7: The catalyst of Embodiment 4, in which M is Co.

Embodiment 8: The catalyst of any one of Embodiments 1-7 in which

is two bidentate ligands.

Embodiment 9: The catalyst of Embodiment 8, in which said bidentate ligand is as shown in Figure 1 , or a substituted analogue thereof. Embodiment 10: The catalyst of any one of Embodiments 1-7 in which

tetradentate ligand.

Embodiment 11 : The catalyst of Embodiment 10 in which said tetradentate ligand is selected from those shown in Figure 3, or a substituted analogue thereof.

Embodiment 12: The catalyst of Embodiment 11 , in which said tetradentate ligand is a salen ligand or salen derivative ligand.

Embodiment 13: The catalyst of Embodiment 12, wherein said salen ligand or salen derivative is selected from those shown in Figure 3a.

Embodiment 14: The catalyst of Embodiment 11 , in which said tetradentate ligand is a porphyrin ligand.

Embodiment 15: The catalyst of Embodiment 14, wherein said porphyrin ligand is as shown in Figure 3b.

Embodiment 16: The catalyst of any preceding Embodiment, wherein v is 0.

Embodiment 17: The catalyst of any one of Embodiments 1 to 15, wherein v is 1.

Embodiment 18: The catalyst of any one of Embodiments 1 to 15, wherein v is 2.

Embodiment 19: The catalyst of any one of Embodiments 1 to 15, wherein v is 3.

Embodiment 20: The catalyst of any one of Embodiments 1 to 15, wherein v is 4.

Embodiment 21 : The catalyst of any one of Embodiments 1 to 15 and 17 to 20, wherein m is 1.

Embodiment 22: The catalyst of any one of Embodiments 1 to 15 and 17 to 20, wherein m is 2.

Embodiment 23: The catalyst of any one of Embodiments 1 to 15 and 17 to 20, wherein m is

3.

Embodiment 24: The catalyst of any one of Embodiments 1 to 15 and 17 to 20, wherein m is

4.

Embodiment 25: The catalyst of any one of Embodiments 1 to 15 and 17 to 24, wherein v’ is 0.

Embodiment 26: The catalyst of any one of Embodiments 1 to 24, wherein v’ is 1.

Embodiment 27: The catalyst of any one of Embodiments 1 to 24, wherein v’ is 2.

Embodiment 28: The catalyst of any one of Embodiments 1 to 24, wherein v’ is 3.

Embodiment 29: The catalyst of any one of Embodiments 1 to 24, wherein v’ is 4.

Embodiment 30: The catalyst of any one of Embodiments 1 to 15 and 17 to 29 in which the linker group is selected from the following:

where ^* represents the site of attachment to a ligand, and each # represents a site of attachment of an activating group. Embodiment 31 : The catalyst of Embodiment 30, wherein the linker group— is substituted or unsubstituted, branched or unbranched Ci-₆ alkyl.

Embodiment 32: The catalyst of any one of Embodiments 1 to 24 and 26 to 31 , wherein L is an anionic ligand that is capable of ring opening an epoxide and is independently selected from 0C(O)R^x, OR^x, halide, carbonate, amino, nitro, nitrate, alkyl, aryl, heteroaryl, phosphinate or OSC>2R^x, and wherein R^x is optionally substituted alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl or alkylaryl.

Embodiment 33: The catalyst of Embodiment 32, wherein L is lactate, 3-hydroxypropanoate, Cl, Br, I, NO3, optionally substituted phenoxide, 0C(O)CF₃ or 0C(O)CH₃ groups.

Embodiment 34: The catalyst of Embodiment 33, wherein L is Cl.

Embodiment 35: The catalyst of Embodiment 33, wherein L is NO3.

Embodiment 36: The catalyst of Embodiment 33, wherein L is optionally substituted phenoxide.

Embodiment 37: The catalyst of Embodiment 33, wherein L is 0C(O)CF₃.

Embodiment 38: The catalyst of Embodiment 33, wherein L is 0C(O)CH₃.

Embodiment 39: The catalyst of Embodiment 32, wherein L is 0C(O)R^x and wherein R^x is optionally substituted alkyl, preferably wherein R^x is a C1 -6 alkyl group substituted with one or more -OH groups, more preferably wherein L is 3-hydroxypropanoate or lactate.

Embodiment 40: The catalyst of any one of Embodiments 1 to 24 and 26 to 31 , wherein L is a neutral ligand and is independently selected from water, methanol, pyridine,

methylimidazole (for example N-methyl imidazole) and dimethylaminopyridine (for example, 4-methylaminopyridine).

Embodiment 41 : The catalyst of any one of Embodiments 1 to 24 and 26 to 31 comprising at least one anionic L ligand that is capable of ring opening an epoxide and at least one neutral L ligand, preferably wherein the at least one anionic L ligand that is capable of ring opening an epoxide is as defined in any one of Embodiments 32-39, and the at least one neutral L ligand is as defined in Embodiment 40.

Embodiment 42: The catalyst of any one of Embodiments 1 to 15 and 17 to 41 , wherein the activating group E is a nitrogen-containing activating group.

Embodiment 43: The catalyst of Embodiment 42, wherein the activating group E is selected from those shown in Figure 4, Figure 5 or Figure 5a.

Embodiment 44: The catalyst of Embodiment 43, wherein the activating group E is selected from those shown in Figure 5a.

Embodiment 45: The catalyst of any one of Embodiments 43 to 45, wherein each Ra is independently H; optionally substituted C1 -20 aliphatic; optionally substituted C1 -20

heteroaliphatic; optionally substituted phenyl; optionally substituted 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; optionally substituted 7-14 carbon saturated, partially unsaturated or aromatic polycyclic carbocycle; optionally substituted 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from O, N or S; optionally substituted 3- to 8- membered saturated or partially unsaturated heterocyclic ring having 1-3 heteroatoms independently selected from O, N or S; optionally substituted 6- to 12- membered polycyclic saturated or partially unsaturated heterocycle having 1-5 heteroatoms independently selected from O, N or S; or optionally substituted 8- to 10-membered bicyclic heteroaryl ring having 1-5 heteroatoms independently selected from O, N or S; and

wherein two or more Ra groups can be taken together with intervening atoms to form one or more optionally substituted rings optionally containing one or more additional heteroatoms;

X- is an anion;

ring A is an optionally substituted 5- to 10-membered heteroaryl group;

Rd is hydrogen, hydroxyl, optionally substituted C1-20 aliphatic;

each occurrence of Rs and Rc|) is independently H; optionally substituted C1 -20 aliphatic; optionally substituted C1 -20 heteroaliphatic; optionally substituted phenyl; optionally substituted 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; optionally substituted 7 to 14 carbon saturated, partially unsaturated or aromatic polycyclic carbocycle; optionally substituted 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from O, N or S; optionally substituted 3- to 8-membered saturated or partially unsaturated heterocyclic ring having 1-3 heteroatoms independently selected from O, N or S; optionally substituted 6- to 12-membered polycyclic saturated or partially unsaturated heterocycle having 1-5 heteroatoms independently selected from O, N or S; or optionally substituted 8- to 10-membered bicyclic heteroaryl ring having 1-5 heteroatoms independently selected from O, N or S; and

wherein an R_e or RF group can be taken with an Ra group to form one or more optionally substituted rings;

Rg is H; a protecting group; optionally substituted C1 -20 acyl; optionally substituted C1 -20 aliphatic; optionally substituted C1 -20 heteroaliphatic; optionally substituted phenyl; optionally substituted 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; optionally substituted 7-14 carbon saturated, partially unsaturated or aromatic polycyclic carbocycle; optionally substituted 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from O, N or S; optionally substituted 3- to 8-membered saturated or partially unsaturated heterocyclic ring having 1-3 heteroatoms independently selected from O, N or S; optionally substituted 6- to 12-membered polycyclic saturated or partially unsaturated heterocycle having 1-5 heteroatoms independently selected from O, N or S; or optionally substituted 8- to 10-membered bicyclic heteroaryl ring having 1-5 heteroatoms independently selected from O, N or S; and

each occurrence of RK is independently selected from the group consisting of: Cl, Br, F, I,

NO2, -CN, -SR^b, -S(O)R^b, -S(O)₂R^b, -NR^bC(O)R^b, -OC(O)R^b, -C0₂R^b, -NCO, -N₃, -ORy, -OC(O)N(R^b)₂, -N(R^b)₂, -NR^bC(O)R^b, -NR^bC(O)OR^b; optionally substituted Ci-₂₀ aliphatic; optionally substituted Ci-_2o heteroaliphatic; optionally substituted phenyl; optionally substituted 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; optionally substituted 7-14 carbon saturated, partially unsaturated or aromatic polycyclic carbocycle; optionally substituted 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from O, N or S; optionally substituted 3- to 8-membered saturated or partially unsaturated heterocyclic ring having 1-3 heteroatoms independently selected from O, N or S; optionally substituted 6- to 12-membered polycyclic saturated or partially unsaturated heterocycle having 1-5 heteroatoms independently selected from O, N or S; or optionally substituted 8- to 10-membered bicyclic heteroaryl ring having 1-5 heteroatoms independently selected from O, N or S; where each occurrence of R^b is independently -H; optionally substituted C1 -6 aliphatic; optionally substituted 3- to 7- membered heterocyclic; optionally substituted phenyl; and optionally substituted 8- to 10- membered aryl; and

Embodiment 46: The catalyst of Embodiment 42 or 45, wherein the activating group E is

Embodiment 47: The catalyst of Embodiment 42 or 45, wherein the activating group E is

Embodiment 48: The catalyst of Embodiment 42 or 45, wherein the activating group E is

Embodiment 49: The catalyst of Embodiment 42 or 45, wherein the activating group E is

Embodiment 50: The catalyst of Embodiment 42 or 45, wherein the activating group E is

Embodiment 51 : The catalyst of Embodiment 42 or 45, wherein the activating group E is

Embodiment 52: The catalyst of any one of Embodiments 46 to 51 , wherein each Ra is independently selected from H; optionally substituted Ci-₆ aliphatic; optionally substituted Ci- 6 heteroaliphatic; and optionally substituted 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; and

X- is selected from -OR^a, -O(C=O)R^a, -O(C=O)OR^a, -O(C=O)N(R^a)₂, -N(R^a)(C=O)R^a, BF₄, - CN, -F, -Br, -I and -Cl, wherein each R^a is independently selected from H, optionally substituted Ci-₆ aliphatic, optionally substituted Ci-₆ heteroaliphatic, optionally substituted C₆- 12 aryl and optionally substituted C3-1 1 heteroaryl.

Embodiment 53: The catalyst of any one of Embodiments 46 to 51 , wherein each Ra is independently selected from H; optionally substituted C1 -6 aliphatic; optionally substituted Ci- 6 heteroaliphatic and optionally substituted - to 8-membered saturated or partially

unsaturated monocyclic carbocycle; and

X- is selected from -F, -Br, -I, -Cl, BF₄, OAc, O₂COCF₃, NO₃, OR^a and 0(C=O)R^a, wherein R^a is selected from H, optionally substituted C1 -6 alkyl, optionally substituted C1 -6 heteroalkyl, optionally substituted C_6-12 aryl and optionally substituted C_3-11 heteroaryl.

Embodiment 54: The catalyst of any one of Embodiments 1 to 15 and 17 to 41 , wherein the activating group E is a phosphorous-containing activating group.

Embodiment 55: The catalyst of Embodiment 54, wherein the phosphorous-containing activating group E is selected from those shown in Figure 6.

Embodiment 56: The catalyst of Embodiment 55, wherein the phosphorous-containing activating group E is wherein Ra and X- are as defined in Embodiment 52

above.

Embodiment 57: The catalyst of Embodiment 56, wherein Ra and X- are as defined in Embodiment 53.

Embodiment 58: The catalyst of any one of Embodiments 1 to 15 and 17 to 41 , wherein the activating group E is a mixed nitrogen and phosphorous-containing activating group. Embodiment 59: The catalyst of Embodiment 58, wherein the mixed nitrogen and phosphorous-containing activating group E is selected from those shown in Figure 7.

Particularly preferred catalysts of formula (I) correspond to Embodiments 4, 13, 18, 22, 31 and 44 above.

Most preferred catalysts of formula (I) are as shown below:

wherein X is an anion, preferably wherein X- is selected from F, Br, I, Cl, BF₄, OAc,

O₂COCF₃, NO₃, OR^a and 0(C=O)R^a, wherein R^a is selected from H, optionally substituted C_1-6 alkyl, optionally substituted C_1-6 heteroalkyl, optionally substituted C_6-12 aryl and optionally substituted C_3-11 heteroaryl;

L is a coordinating ligand that is capable of ring-opening an epoxide (preferably L is an anionic ligand which is capable of ring opening an epoxide), preferably wherein L is selected from 0C(O)R^x (e.g. OAc, 0C(O)CF₃, lactate, 3-hydroxypropanoate), halogen, NO₃, OSO₂R^X, (e.g. OSO(CH₃)₂), R^x (e.g. Et, Me), OR^x (e.g. OMe, O^jPr, 0*Bu, OPh, OBn), Cl, Br, I, F, N(iPr)₂ or N(SiMe₃)_2, salicylate and alkyl or aryl phosphinate (e.g. dioctyl phosphinate); R^x is optionally substituted alkyl, alkenyl, alkynyl, heteroalkyl, aryl, or heteroaryl; and

M is Al, Co or Cr.

DMC catalysts are complicated compounds which comprise at least two metal centres and cyanide ligands. The DMC catalyst may additionally comprise at least one of: one or more complexing agents, water, a metal salt and/or an acid (e.g. in non-stoichiometric amounts).

The first two of the at least two metal centres may be represented by M’ and M”.

M’ may be selected from Zn(ll), Ru(ll), Ru(lll), Fe(ll), Ni(ll), Mn(ll), Co(ll), Sn(ll), Pb(ll), Fe(lll), Mo(IV), Mo(VI), Al(lll), V(V), V(VI), Sr(ll), W(IV), W(VI), Cu(ll), and Cr(lll), M’ is optionally selected from Zn(ll), Fe(ll), Co(ll) and Ni(ll), optionally M’ is Zn(ll). M” is selected from Fe(ll), Fe(lll), Co(ll), Co(lll), Cr(ll), Cr(lll), Mn(ll), Mn(lll), Ir(lll), Ni(ll), Rh(lll), Ru(ll), V(IV), and V(V), optionally M” is selected from Co(ll), Co(lll), Fe(ll), Fe(lll), Cr(lll), Ir(lll) and Ni(ll), optionally M” is selected from Co(ll) and Co(lll).

It will be appreciated that the above optional definitions for M’ and M” may be combined. For example, optionally M’ may be selected from Zn(ll), Fe(ll), Co(ll) and Ni(ll), and M” may optionally selected form be Co(ll), Co(lll), Fe(ll), Fe(lll), Cr(lll), Ir(lll) and Ni(ll). For example, M’ may optionally be Zn(ll) and M” may optionally be selected from Co(ll) and Co(lll).

If a further metal centre(s) is present, the further metal centre may be further selected from the definition of M’ or M”.

Examples of DMC catalysts which can be used in the method of the invention include those described in US 3,427,256, US 5,536,883, US 6,291 ,388, US 6,486,361 , US 6,608,231 , US 7,008,900, US 5,482,908, US 5,780,584, US 5,783,513, US 5,158,922, US 5,693,584, US

7,811 ,958, US 6,835,687, US 6,699,961 , US 6,716,788, US 6,977,236, US 7,968,754, US

7,034,103, US 4,826,953, US 4,500 704, US 7,977,501 , US 9,315,622, EP-A-1568414, EP-

A-1529566, US2017/0247509 and WO 2015/022290, the entire contents of which are incorporated by reference.

DMC catalysts which are useful in the invention may be produced by treating a solution (such as an aqueous solution) of a metal salt with a solution (such as an aqueous solution) of a metal cyanide salt in the presence of one or more complexing agents, water, and/or an acid. Suitable metal salts include compounds of the formula M’(X’)_P, wherein M’ is selected from Zn(ll), Ru(ll), Ru(lll), Fe(ll), Ni(ll), Mn(ll), Co(ll), Sn(ll), Pb(ll), Fe(lll), Mo(IV), Mo(VI), Al(lll), V(V), V(VI), Sr(ll), W(IV), W(VI), Cu(ll), and Cr(lll), and M’ is optionally selected from Zn(ll), Fe(ll), Co(ll) and Ni(ll), optionally M’ is Zn(ll). X’ is an anion selected from halide, oxide, hydroxide, sulphate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate and nitrate, optionally X’ is halide p is an integer of 1 or more, and the charge on the anion multiplied by p satisfies the valency of M’. Examples of suitable metal salts include zinc chloride, zinc bromide, zinc acetate, zinc acetonylacetonate, zinc benzoate, zinc nitrate, iron(ll) sulphate, iron (II) bromide, cobalt(ll) chloride, cobalt(ll) thiocyanate, nickel(ll) formate, nickel(ll) nitrate, and mixtures thereof.

Suitable metal cyanide salts include compounds of the formula (Y’)q[M”(CN)_b(A’)_c], wherein M” is selected from Fe(ll), Fe(lll), Co(ll), Co(lll), Cr(ll), Cr(lll), Mn(ll), Mn(lll), Ir(lll), Ni(ll), Rh(lll), Ru(ll), V(IV), and V(V), optionally M” is selected from Co(ll), Co(lll), Fe(ll), Fe(lll), Cr(lll), Ir(lll) and Ni(ll), optionally M” is selected from Co(ll) and Co(lll). Y’ is a proton (H⁺) or an alkali metal ion or an alkaline earth metal ion (such as K⁺), A’ is an anion selected from halide, oxide, hydroxide, sulphate, cyanide oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate and nitrate q and b are integers of 1 or more, optionally b is 4 or 6. c may be 0 or an integer of 1 or more. The sum of the charges on the ions Y’, CN and A’ multiplied by q, b and c respectively (e.g. Y’ x q + CN x b + A’ x c) satisfies the valency of M”. Examples of suitable metal cyanide salts include potassium hexacyanocobaltate(lll), potassium hexacyanoferrate(ll), potassium hexacyanoferrate(lll), calcium hexacyanocobaltate(lll), lithium hexacyanocolbaltate(lll), and mixtures thereof.

Suitable complexing agents include (poly)ethers, polyether carbonates, polycarbonates, poly(tetramethylene ether diol)s, ketones, esters, amides, alcohols, ureas and the like, or combinations thereof. Exemplary complexing agents include propylene glycol, polypropylene glycol (PPG), (m)ethoxy ethylene glycol, dimethoxyethane, tert-butyl alcohol, ethylene glycol monomethyl ether, diglyme, triglyme, methanol, ethanol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, 3-buten-1-ol, 2-methyl-3-buten-2-ol, 2-methyl-3-butyn-2- ol, 3-methyl-1-pentyn-3-ol, etc, or combination a thereof. It will be appreciated that the alcohol may be saturated or may contain an unsaturated moiety (e.g. a double or triple bond). Multiple (i.e. more than one different type of) complexing agents may be present in the DMC catalysts used in the present invention.

The DMC catalyst may comprise a complexing agent which is a polyether, polyether carbonate or polycarbonate.

Suitable polyethers for use in the DMC catalyst of the present invention include those produced by ring-opening polymerisation of cyclic ethers, and include epoxide polymers, oxetane polymers, tetrahydrofuran polymers etc. Any method of catalysis can be used to make the polyethers. The polyethers can have any desired end groups, including, for example, hydroxyl, amine, ester, ether, or the like. Optional polyethers for use in the DMC catalyst of the present invention are polyether polyols having between 2 and 8 hydroxyl groups. It is also optional that polyethers for use in the DMC catalyst of the present invention have a molecular weight between about 1 ,000 Daltons and about 10,000 Daltons, optionally between about 1 ,000 Daltons and about 5,000 Daltons. Polyether polyols useful in the DMC catalyst of the present invention include PPG polyols, EO-capped PPG polyols, mixed EO-PO polyols, butylene oxide polymers, butylene oxide copolymers with ethylene oxide and/or propylene oxide, polytetramethylene ether glycols, and the like. Optional polyethers include PPGs, such as PPG polyols, particularly diols and triols, said PPGs having molecular weights of from about 250 Daltons to about 8,000 Daltons, optionally from about 400 Daltons to about 4,000 Daltons.

Suitable polyether carbonates for use in the DMC catalyst of the present invention may be obtained by the catalytic reaction of alkylene oxides and carbon dioxide in the presence of a suitable starter or initiator compound. The polyether carbonates used as the complexing agent can also be produced by other methods known to the person skilled in the art, for example by partial alcoholysis of polycarbonate polyols with di- or tri-functional hydroxy compounds. The polyether carbonates used as complexing agents in the DMC catalyst of the present invention optionally have an average hydroxyl functionality of 1 to 6, optionally 2 to 3, optionally 2.

Suitable polycarbonates for use in the DMC catalyst of the present invention may be obtained by the polycondensation of difunctional hydroxy compounds (generally bis-hydroxy compounds such as alkanediols or bisphenols) with carbonic acid derivatives such as, for example, phosgene or bis[chlorocarbonyloxy] compounds, carbonic acid diesters (such as diphenyl carbonate or dimethyl carbonate) or urea. Methods for producing polycarbonates are generally well known and are described in detail in for example“Houben-Weyl,

Methoden der organischen Chemie”, Volume E20, Makromolekulare Stoffe, 4^th Edition,

1987, p. 1443-1457,“Ullmann's Encyclopaedia of Industrial Chemistry”, Volume A21 , 5^th Edition, 1992, p. 207-215 and“Encyclopaedia of Polymer Science and Engineering”, Volume 11 , 2^nd Edition, 1988, p. 648-718. Aliphatic polycarbonate diols having a molecular weight of from about 500 Daltons to 5000 Daltons, optionally from 1000 Daltons to 3000 Daltons, are optionally used in the DMC catalyst of the present invention. These are generally obtained from non-vicinal diols by reaction with diaryl carbonate, dialkyl carbonate, dioxolanones, phosgene, bischloroformic acid esters or urea (see, for example, EP-A 292 772). Suitable non-vicinal diols are in particular 1 ,4-butanediol, neopentyl glycol, 1 ,5-pentanediol, 2-methyl- 1 ,5-pentanediol, 3-methyl-1 ,5-pentanediol, 1 ,6-hexanediol, bis-(6-hydroxyhexyl)ether, 1 ,7- heptanediol, 1 ,8-octanediol, 2-methyl-1 ,8-octanediol, 1 ,9-nonanediol, 1 ,10-decanediol, 1 ,4- bis-hydroxymethyl cyclohexane, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, alkoxylation products of diols with ethylene oxide and/or propylene oxide and/or tetrahydrofuran with molar masses up to 1000 Daltons, optionally between 200 Daltons and 700 Daltons, and in rarer cases the dimer diols, which are obtainable by reducing both carboxyl groups of dimer acids, which in turn can be obtained by dimerisation of unsaturated vegetable fatty acids. The non-vicinal diols can be used individually or in mixtures. The reaction can be catalysed by bases or transition metal compounds in the manner known to the person skilled in the art. Other complexing agents that may be useful in the present invention include poly(tetramethylene ether diols). Poly(tetramethylene ether diols) are polyether polyols based on tetramethylene ether glycol, also known as polytetrahydrofuran (PTHF) or polyoxybutylene glycol. These poly(tetramethylene ether diols) comprise two OH groups per molecule. They can be produced by cationic polymerisation of tetrahydrofuran (THF) with the aid of catalysts.

Complexing agents, as defined above, may be used to increase or decrease the crystallinity of the resulting DMC catalyst.

Suitable acids for use in the DMC catalyst of the present invention may have the formula H_rX”’, where X’” is an anion selected from halide, sulfate, phosphate, borate, chlorate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate and nitrate, optionally X’” is a halide r is an integer corresponding to the charge on the counterion X’”. For example, when X’” is Cl- , r will be 1 , i.e. the acid will be HCI.

If present, particularly optional acids for use in the DMC catalyst of the present invention having the formula H_rX”’ include the following: HCI, H₂SO₄, HNO₃, H₃PO₄, HF, HI, HBr,

H₃BO₃ and HCIO₄. For example, HCI, HBr and H₂SO₄.

It will also be appreciated that an alkali metal salt (e.g. an alkali metal hydroxide such as KOH, an alkali metal oxide or an alkali metal carbonate) may be added to the reaction mixture during synthesis of the DMC catalyst. For example, the alkali metal salt may be added to the reaction mixture after the metal salt (M’(X’)_P) has been added to the metal cyanide salt ((Y)q[M”(CN)_b(A)_c]).

In one common preparation, an aqueous solution of zinc chloride (excess) is mixed with an aqueous solution of potassium hexacyanocobaltate, and a complexing agent (such as dimethoxyethane or aqueous tert-butyl alcohol) is added to the resulting slurry. After filtration and washing of the catalyst with an aqueous solution of the complexing agent (e.g. aqueous dimethoxyethane), an active catalyst is obtained. Subsequent washing step(s) may be carried out using just the complexing agent, in order to remove excess water. Each one is followed by a filtration step.

In an alternative preparation, several separate solutions may be prepared and then combined in order. For example, the following solutions may be prepared: 1. a solution of a metal cyanide (e.g. potassium hexacyanocobaltate)

2. a solution of a metal salt e.g. (zinc chloride (excess))

3. a solution of a first complexing agent (e.g. PPG diol)

4. a solution of a second complexing agent (e.g. tert-butyl alcohol).

In this method, solutions 1 and 2 are combined immediately, followed by slow addition of solution 4, optionally whilst stirring rapidly. Solution 3 may be added once the addition of solution 4 is complete, or shortly thereafter. The catalyst is removed from the reaction mixture via filtration, and is subsequently washed with a solution of the complexing agents.

If water is desired in the DMC catalyst, then the above solutions (e.g. solutions 1 to 4) may be aqueous solutions. However, it will be understood that anhydrous DMC catalysts (i.e. DMC catalysts without any water present) may be prepared if the solutions described in the above preparations are anhydrous solutions. To avoid hydrating the DMC catalyst and thereby introducing water molecules, any further processing steps (washing, filtration etc.) may be conducted using anhydrous solvents.

In one common preparation, several separate solutions may be prepared and then combined in order. For example, the following solutions may be prepared:

1. a solution of a metal salt (e.g. zinc chloride (excess)) and a second complexing agent (e.g. tert-butyl alcohol)

2. a solution of a metal cyanide (e.g. potassium hexacyanocobaltate)

3. a solution of a first and a second complexing agent (e.g. the first complexing agent may be a polymer (for example, polypropylene glycol diol) and the second

complexing agent may be tert-butyl alcohol)

In this method, solutions 1 and 2 are combined slowly (e.g. over 1 hour) at a raised temperature (e.g. above 25°C, such as about 50°C) while stirring (e.g. at 450 rpm). After addition is complete the stirring rate is increased for 1 hour (e.g. up to 900 rpm). The stirring rate is then decreased to a slow rate (e.g. to 200 rpm) and solution 3 is added quickly with low stirring. The mixture is filtered. The catalyst solids may be re-slurried in a solution of the second complexing agent at high stirring rate (e.g. about 900 rpm) before addition of the first complexing agent at low stirring rate (e.g. 200 rpm). The mixture is then filtered. This step may be repeated more than once. The resulting catalyst cake may be dried under vacuum (with heating e.g. to 60°C).

Alternatively, after the mixture is first filtered it can be re-slurried at a raised temperature (e.g. above 25°C, such as about 50°C) in a solution of the first complexing agent (and no second or further complexing agent) and then homogenized by stirring. It is then filtered after this step. The catalyst solids are then re-slurried in a mixture of the first and second complexing agents. For example, the catalyst solids are re-slurried in the second complexing agent at a raised temperature (e.g. above 25°C, such as about 50°C) and subsequently the first complexing agent is added and mixture homogenized by stirring. The mixture is filtered and the catalyst is dried under vacuum with heating (e.g. to 100°C).

It will be appreciated that the DMC catalyst may comprise:

M’_d[M”_e(CN)_f]_g wherein M’ and M” are as defined above, d, e, f and g are integers, and are chosen such that the DMC catalyst has electroneutrality. Optionally, d is 3. Optionally, e is 1. Optionally f is 6. Optionally g is 2. Optionally, M’ is selected from Zn(ll), Fe(ll), Co(ll) and Ni(ll), optionally M’ is Zn(ll). Optionally M” is selected from Co(ll), Co(lll), Fe(ll), Fe(lll), Cr(lll), Ir(lll) and Ni(ll), optionally M” is Co(ll) or Co(lll).

It will be appreciated that any of these optional features may be combined, for example, d is 3, e is 1 , f is 6 and g is 2, M’ is Zn(ll) and M” is Co(lll).

Suitable DMC catalysts of the above formula may include zinc hexacyanocobaltate(lll), zinc hexacyanoferrate(lll), nickel hexacyanoferrate(ll), and cobalt hexacyanocobaltate(lll).

There has been a lot of development in the field of DMC catalysts, and the skilled person will appreciate that the DMC catalyst may comprise, in addition to the formula above, further additives to enhance the activity of the catalyst. Thus, while the above formula may form the “core” of the DMC catalyst, the DMC catalyst may additionally comprise stoichiometric or non-stoichiometric amounts of one or more additional components, such as at least one complexing agent, an acid, a metal salt, and/or water.

For example, the DMC catalyst may have the following formula:

wherein M’, M”, X’”, d, e, f and g are as defined above. M’” can be M’ and/or M”. X” is an anion selected from halide, oxide, hydroxide, sulphate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate and nitrate, optionally X” is halide i is an integer of 1 or more, and the charge on the anion X” multiplied by i satisfies the valency of M’”. r is an integer that corresponds to the charge on the counterion X’”. For example, when X’” is Cl-, r will be 1. I is 0, or a number between 0.1 and 5. Optionally, I is between 0.15 and 1.5.

R^c is a complexing agent, and may be as defined above. For example, R^c may be a

(poly)ether, a polyether carbonate, a polycarbonate, a poly(tetramethylene ether diol), a ketone, an ester, an amide, an alcohol (e.g. a Ci-e alcohol), a urea and the like, such as propylene glycol, polypropylene glycol, (m)ethoxy ethylene glycol, dimethoxyethane, tert- butyl alcohol, ethylene glycol monomethyl ether, diglyme, triglyme, methanol, ethanol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, 3-buten-1-ol, 2-methyl- 3-buten-2-ol, 2-methyl-3-butyn-2-ol, 3-methyl-1-pentyn-3-ol, for example, R^c may be tert- butyl alcohol, dimethoxyethane, or polypropylene glycol.

As indicated above, more than one complexing agent may be present in the DMC catalysts used in the present invention. Optionally, a combination of the complexing agents tert-butyl alcohol and polypropylene glycol may be present.

It will be appreciated that if the water, complexing agent, acid and/or metal salt are not present in the DMC catalyst, h, j, k and/or I will be zero respectively. If the water, complexing agent, acid and/or metal salt are present, then h, j, k and/or I are a positive number and may, for example, be between 0 and 20. For example, h may be between 0.1 and 4. j may be between 0.1 and 6. k may be between 0 and 20, e.g. between 0.1 and 10, such as between 0.1 and 5. I may be between 0.1 and 5, such as between 0.15 and 1.5.

As set out above, DMC catalysts are complicated structures, and thus the above formula including the additional components is not intended to be limiting. Instead, the skilled person will appreciate that this definition is not exhaustive of the DMC catalysts which are capable of being used in the invention.

An exemplary DMC catalyst is of the formula

wherein h, k and j are as defined above. For example, h may be from 0 to 4 (e.g. from 0.1 to 4), k may be from 0 to 20 (e.g. from 0.1 to 10), and j may be from 0 to 6 (e.g. from 0.1 to 6). Examples

Methods

Nuclear Magnetic Resonance Spectroscopy

¹H NMR spectra were recorded on a Bruker AV-400 instrument, using the solvent CDC .

The assessment of polyether and polycarbonate content of the polyethercarbonate polyols and polyether carbonates has been reported in a number of different ways. In order to calculate the molar carbonate content and the CO2 wt% in the polyethercarbonate polyols and polyether carbonates, the method described in US2014/0323670 was used herein. The method is as follows:

The samples were dissolved in deuterated chloroform and measured on a Bruker spectrometer. The relevant resonances in the ¹H-NMR spectra used for integration (in the case that 1 ,6-hexanediol is used as a starter) were:

Table A:

The resonances A, C-F have been previously defined for polyethercarbonates containing a low proportion of carbonate linkages in the methods described in US2014/0323670. An extra resonance (B, 1.18-1.25 ppm) has been identified that is only present in significant quantities in polyethercarbonates with a high carbonate content. It has been assigned (by 2D NMR) as a terminal propylene CH₃ group between a carbonate unit and a hydroxyl end group. It is therefore added to the total carbonate units (C) as described in US2014/0323670. Carbonate/ether ratio (m/n+m): molar ratio of carbonate and ether linkages:

CO2 wt % in polyol: amount of CO2 incorporated into the total polyol:

Wherein 44 is the mass of CO2 within a carbonate unit, 58 is the mass of a polyether unit, 102 is the mass of a polycarbonate unit and 118 is the mass of the hexanediol starter (the factor 0.75 is added as the hexanediol resonance corresponds to 4 protons whilst all the other resonances correspond to 3). This is the total proportion of CO2 that is present in the entire polyol. If other starters are used it is appreciated the relevant NMR signals, relative integrations and molecular weights will be used in the calculation.

Furthermore, resonance C can be broken down into two different resonances. From 1.26- 1.32 ppm (C¹) corresponds to the propylene CH₃ in a polymer unit between a carbonate and an ether linkage (a polyethercarbonate, PEC linkage) whilst the resonance from 1.32-1.38 ppm (C²) comes from a propylene CH₃ in a polymer unit in between two carbonate linkages (a polycarbonate, PC linkage). The ratio of PEC, PC and PE linkages gives an indication of the structure of the polymer. A completely blocked structure will contain very few PEC linkages (only those at the block interfaces), whilst a more random structure will include a significant proportion of PEC linkages where both polyether and polycarbonate units are adjacent to each other in the polymer backbone. The ratio of these two units gives an indication of the structure.

Polyethercarbonate poly carbonate linkage ratio:

Gel Permeation Chromatography

GPC measurements were carried out against narrow polydispersity polyethylene glycol) or polystyrene standards in THF using an Agilent 1260 Infinity machine equipped with Agilent PLgel Mixed-E columns.

Mass Spectroscopy All mass spectrometry measurements were performed using a MALDI micro MX micromass instrument.

Example 1

Synthesis of DMC catalyst according to US5482908 example 1 (Catalyst 2)

The synthesis described in Example 1 of US5482908 was followed except the 4000 molecular weight polypropylene glycol diol was replaced with a 2000 molecular weight polypropylene glycol diol:

Potassium hexacyanocobaltate (8.0g) was dissolved in deionised (Dl) water (140 ml_) in a beaker (solution 1). Zinc chloride (25 g) was dissolved in Dl water (40 ml_) in a second beaker (solution 2). A third beaker containing solution 3 was prepared: a mixture of Dl water (200 ml_), tert-butyl alcohol (2 ml_) and polyol (2g of a 2000 mol. wt. polypropylene glycol diol). Solutions 1 and 2 were mixed together using a mechanical stirrer. Immediately a 50/50 (by volume) mixture of tert-butyl alcohol and Dl water (200 ml_ total) was added to the zinc hexacyanocobaltate mixture, and the product was stirred vigorously for 10 min. Solution 3 (polyol/water/tert-butyl alcohol mixture) was added to the aqueous slurry of zinc

hexacyanocobaltate and the product stirred magnetically for 3 min. The mixture was filtered under pressure to isolate the solids. The solid cake was reslurried in tert-butyl alcohol (140 ml_), Dl water (60 ml_), and an additional 2g of the 2000 mol. wt. polypropylene glycol diol. Then mixture was stirred vigorously for 10 min. and filtered. The solid cake was reslurried in tert-butyl alcohol (200 ml_) and an additional 1 g of 2000 mol. wt. polypropylene glycol diol and stirred vigorously for 10 minutes, then filtered. The resulting solid catalyst was dried under vacuum (<1 mbar) at 50 °C to constant weight. The yield of dry, powdery catalyst was 8.5g.

Example 2

2.7 mg of the DMC catalyst 2 was taken into a 100 mL oven dried reactor along with hexanediol (0.964 g). The DMC and starter were dried at 120 °C under vacuum for 1 hour.

The reactor was cooled down to room temperature and ethyl acetate (10 mL) was injected into the vessel via a syringe under continuous flow of CO2 gas. The vessel was heated to the desired temperature (130 °C) after which 2.49 g of total propylene oxide was added in 3 bursts (0.83g each) with 20 minutes between each.

Catalyst 1

The reactor was cooled to 65 °C and pressurised with C0₂ (5 bar). A mixture of catalyst 1 (26.7 mg), bis(triphenylphosphine)iminium chloride (PPNCI) (20.8 mg) and EtOAc (5 ml_) were stirred under anhydrous conditions for 5 minutes. The catalyst/PPNCI mixture was then injected into the vessel via a HPLC pump, washed through with a further 5 ml_ of EtOAc.

PO (3.32 g) was added via a HPLC pump and the reaction stirred for 1 hour. The remaining PO (10.79 g) was added over 2.5 hours via a HPLC pump and followed by a 45 minute wait. The reactor temperature was then raised to 85 °C. Once the reaction was finished, the reactor was cooled to below 10°C and the pressure was released. NMR and GPC were measured immediately.

Example 3

2.7 mg of the DMC catalyst 2 was taken into a 100 mL oven dried reactor along with 1 , 12- dodecanediol (0.77 g). The DMC and starter were dried at 120 °C under vacuum for 1 hour and then the reactor was cooled down to room temperature. A mixture of catalyst 1 (26.7 mg), bis(triphenylphosphine)iminium chloride (PPNCI) (20.8 mg) and EtOAc (10 mL) were stirred for 5 minutes, then injected into the vessel via a syringe under continuous flow of CO2 gas. Propylene oxide (3.32 g) was added via a HPLC pump and the vessel was heated to the desired temperature (73 °C) and pressurised to 5 bar CO2. After 1 h a further 1.66 g PO was added to the reactor followed by a 1 hour wait, then a 1.66 g PO was added, after an additional 1 hour wait the remaining PO (9.6 g) was added over 3 hours via HPLC pump. The reactor was maintained at the desired temperature and pressure overnight. Once the reaction was finished, the reactor was cooled to below 10 °C and the pressure was released. NMR and GPC were measured immediately. Example 4

2.7 mg of the DMC catalyst 2 was taken into a 100 mL oven dried reactor along with hexanediol (0.45 g). The DMC and starter were dried at 120 °C under vacuum for 1 hour and then the reactor was cooled down to room temperature. A mixture of catalyst 1 (26.7 mg), bis(triphenylphosphine)iminium chloride (PPNCI) (20.8 mg) and EtOAc (10 mL) were stirred under anhydrous conditions for 5 minutes, and then this was injected into the vessel via a syringe under continuous flow of CO2 gas. Propylene oxide (3.32 g) was added via a HPLC pump and the vessel was heated to the desired temperature (73 °C) and pressurised to 5 bar CO2. After 1 h a further 1.66 g PO was added to the reactor followed by a 1 hour wait before the remaining PO (1 1.6 g) was added over 3 hours via HPLC pump. The reactor was maintained at the desired temperature and pressure overnight. Once the reaction was finished, the reactor was cooled to below 10 °C and the pressure was released. NMR and GPC were measured immediately.

Example 5

5.7 mg of the DMC catalyst 2 was taken into a 100 mL oven dried reactor along with hexanediol (3.38 g). The DMC and starter were dried at 120 °C under vacuum for 1 hour and then the reactor was cooled down to room temperature. A mixture of catalyst 1 (57.2 mg), bis(triphenylphosphine)iminium chloride (PPNCI) (44.7 mg) and EtOAc (10 mL) were stirred for 5 minutes and then injected into the vessel via a syringe under continuous flow of CO2 gas. Propylene oxide (3.32 g) was added via a HPLC pump and the vessel was heated to the desired temperature (65 °C) and pressurised to 7.5 bar CO2. After 2 hours the temperature was raised to 78 °C and once stabilised a further 1.66 g PO was added to the reactor followed by a 1 hour wait. The remaining PO (1 1.6 g) was added over 3 hours via HPLC pump. Once the reaction was finished, the reactor was cooled to below 10 °C and the pressure was released. NMR and GPC were measured immediately.

Example 6

6 mg of the DMC catalyst 2 was taken into a 100 mL oven dried reactor along with 1 ,12- dodecanediol (1.65 g). The DMC and starter were dried at 120 °C under vacuum for 1 hour and then the reactor was cooled down to room temperature. A mixture of catalyst 1 (57.2 mg), bis(triphenylphosphine)iminium chloride (PPNCI) (46.7 mg) and EtOAc (10 ml_) were stirred for 5 minutes, and then injected into the vessel via a syringe under continuous flow of CO2 gas. Propylene oxide (3.32 g) was added via a HPLC pump and the vessel was heated to the desired temperature (30 °C) and pressurised to 5 bar CO2.

After 2.6 hours a further 0.83 g PO was added to the reactor, followed by a further 1.66 g of PO at 5 hours. The temperature was raised to 80 °C after 6 hours, after a further 2 hours 1.74 g of PO was added. The remaining PO (7.5 g) was added over 1 hour via HPLC pump and the reaction maintained at desired temperature and pressure overnight. Once the reaction was finished, the reactor was cooled to below 10 °C and the pressure was released. NMR and GPC were measured immediately.

Example 7

Catalyst 3

Catalyst 3 was purchased from Strem Chemicals UK.

6 mg of DMC catalyst 2 was taken into a 100 mL oven dried reactor along with 1 ,12- dodecanediol (1.65 g). The DMC and starter were dried at 120 °C under vacuum for 1 hour and then the reactor was cooled down to room temperature. A mixture of catalyst (3) (51.6 mg), bis(triphenylphosphine)iminium chloride (PPNCI) (46.7 mg) and EtOAc (10 mL) were stirred for 5 minutes, and then this was injected into the vessel via a syringe under continuous flow of CO2 gas. Propylene oxide (3.32 g) was added via a HPLC pump and the vessel was heated to the desired temperature (50 °C) and pressurised to 5 bar CO2. At 3 hours a further 0.9 g PO was added to the reactor, followed by a further 1.73 g of PO at 4.5 hours. After 6 hours at 50 °C the temperature was raised to 80 °C and after 90 minutes 1.66 g of PO was added. The remaining PO (8.4 g) was added over 1 hour via HPLC pump and the reaction maintained at desired temperature and pressure overnight. Once the reaction was finished, the reactor was cooled to below 10 °C and the pressure was released. NMR and GPC were measured immediately.

Example 8

6 mg of the DMC catalyst 2 was taken into a 100 ml_ oven dried reactor along with 1 ,12- dodecanediol (1.65 g). The DMC and starter were dried at 120 °C under vacuum for 1 hour and then the reactor was cooled down to room temperature. A mixture of catalyst (3) (51.6 mg), bis(triphenylphosphine)iminium chloride (PPNCI) (47 mg) and EtOAc (10 ml_) were stirred under anhydrous conditions for 5 minutes, and then this was injected into the vessel via a syringe under continuous flow of CO2 gas. Propylene oxide (3.62 g) was added via a HPLC pump and the vessel was heated to the desired temperature (30 °C) and pressurised to 5 bar CO2.

After 2 hours 45 minutes a further 0.9 g PO was added to the reactor, followed by a further 1.73 g of PO at 4.3 hours. The temperature was raised to 80 °C after 6.3 hours, after a 1 hour 20 min wait the remaining PO (9 g) was added over 1 hour via HPLC pump and the reaction maintained at desired temperature and pressure overnight. Once the reaction was finished, the reactor was cooled to below 10 °C and the pressure was released. NMR and GPC were measured immediately.

Table 1 :

Claims

1. A method for preparing a polycarbonate ether polyol, the method comprising the steps of:

(I) (a) mixing catalyst of formula (I), double metal cyanide (DMC) catalyst and

wherein the catalyst of formula (I) has the following structure:

wherein:

M is a metal cation represented by M-(L)_V’;

v’ is an integer that satisfies the valency of M, or is such that the complex

represented by formula (I) above has an overall neutral charge.

2. The method of claim 1 (a) or 1(b), wherein mixture (a) is held at a temperature of between about 50 to 150°C prior to step (II), optionally between about 80 to 130°C.

3. The method of claim 1 (c) or 1(d), wherein mixture (a) is held at a temperature of between about 0 to 120°C prior to step (II), optionally between about 40 to 100°C optionally between about 50 to 90°C.

4. The method of any preceding claim, wherein mixture (a) is held for at least about 1 minute prior to step (II), optionally at least about 5 minutes, optionally at least about 15 minutes, optionally at least about 30 minutes, optionally at least about 1 hour, optionally at least about 2 hours, optionally at least about 5 hours.

5. The method of claim 1(c) or 3, wherein mixture (a) is held for at least about 1 minutes prior to step (II), optionally at least about 5 minutes, optionally at least about 15 minutes, optionally at least about 30 minutes, optionally at least about 1 hour, optionally at least about 2 hours, optionally at least about 3 hours, optionally at least about 4 hours, optionally at least about 8 hours, optionally at least about 16 hours.

6. The method of any preceding claim, wherein mixture (a) comprises less than about 1 wt.% water, optionally less than about 0.5 wt.% water, optionally less than about 0.1 wt.% water, optionally less than about 0.05 wt.% water, optionally about 0 wt.% water.

7. The method of any preceding claim when dependent on claim 1 (a), wherein step (I) comprises firstly mixing catalyst of formula (I), double metal cyanide (DMC) catalyst and optionally carbon dioxide to form mixture (a’), and subsequently adding epoxide and optionally starter compound and/or carbon dioxide to form mixture (a).

8. The method of claim 7, wherein mixture (a’) is held at a temperature of between about 0 to 250°C prior to said subsequently adding, optionally about 40 to 150°C, optionally about 50 to 150°C, optionally about 70 to 140°C, optionally about 80 to 130°C.

9. The method of any preceding claim when dependent on claim 1 (c), wherein step (II) comprises mixing double metal cyanide (DMC) catalyst epoxide, and optionally starter compound, carbon dioxide and/or solvent to form a pre-activated mixture and adding the pre-activated mixture to mixture (a) to form mixture (b).

10. The method of claim 9, wherein the pre-activated mixture is held at a temperature of between about 50 to 110°C prior to adding, optionally between about 60 to 90°C.

11. The method of preceding claim, wherein the method employs a total amount of epoxide, and wherein about 1 to 95% of the total amount of epoxide is mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

12. The method of any preceding claim, wherein the method employs a total amount of starter compound, and wherein about 1 to 95% of the total amount of starter compound is mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

13. The method of any preceding claim, wherein the method employs a total amount of catalyst of formula (I), and wherein about 1 to 100% of the total amount of catalyst of formula (I) is mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

14. The method of any preceding claim, wherein the method employs a total amount of double metal cyanide (DMC) catalyst, and wherein about 1 to 100% of the total amount of double metal cyanide (DMC) catalyst mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

15. The method of any preceding claim, wherein the method employs a total amount of carbon dioxide, and wherein about 1 to 100% of the total amount of carbon dioxide is mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

16. The method of any preceding claim, wherein the method employs a total amount of solvent, and wherein about 1 to 100% of the total amount of solvent is mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

17. The method of any one of claims 1 to 10, wherein the method is continuous, wherein there is a predetermined molar ratio or weight ratio of epoxide to catalyst of formula (I) in mixture (b), and wherein the method further comprises:

18. The method of any one of claims 1 to 10 or 17, wherein the method is continuous, wherein there is a predetermined molar ratio or weight ratio of starter compound to catalyst of formula (I) in mixture (b), and wherein the method further comprises:

19. The method of any one of claims 1 to 10, 17 or 18, wherein the method is continuous, wherein there is a predetermined molar ratio or weight ratio of carbon dioxide to catalyst of formula (I) in mixture (b), and wherein the method further comprises:

20. The method of any one of claims 1 to 10, or 17 to 19, wherein step (III) is conducted such that the molar ratio or weight ratio of epoxide, starter compound, carbon dioxide and/or solvent to catalyst of formula (I) in mixture (g) does not fall below about 75% of said predetermined molar or weight ratio.

21. The method of claim 20, wherein step (III) is conducted such that the molar ratios or weight ratios of epoxide, starter compound, carbon dioxide and solvent to catalyst of formula (I) in mixture (g) do not fall below about 75% of said predetermined molar or weight ratios.

22. The method of any one of claims 1 to 10, or 17 to 21 , wherein the method is continuous, wherein there is a predetermined amount of catalyst of formula (I) in mixture (b), and wherein the method further comprises:

23. The method of claim 22, wherein step (III) is conducted such that the amount of catalyst of formula (I) in the mixture (g) does not fall below about 50% of said predetermined amount.

24. The method of any one of claims 1 to 10, or 17 to 23, wherein the method is continuous, wherein there is a predetermined amount of double metal cyanide (DMC) catalyst in mixture (b), and wherein the method further comprises:

25. The method of claim 24, wherein step (III) is conducted such that the amount of double metal cyanide (DMC) catalyst in mixture (g) does not fall below about 50% of said predetermined amount.

26. The method of any preceding claim, in which there are two starter compounds in mixture (b), wherein the starter compound in step (I) is a first starter compound, and wherein step (II) comprises:

(A) adding one or more of first starter compound, epoxide, carbon dioxide,

(B) adding a second starter compound and optionally epoxide, carbon dioxide, catalyst of formula (I), double metal cyanide (DMC) catalyst and/or solvent to form mixture (b) comprising first starter compound, second starter compound, epoxide, carbon dioxide, catalyst of formula (I), double metal cyanide (DMC) catalyst and optionally solvent.

27. The method of claim 26, wherein step (B) is conducted at least about 1 minutes after step (A), optionally at least about 5 minutes, optionally at least about 15 minutes, optionally at least about 30 minutes, optionally at least about 1 hour, optionally at least about 2 hours, optionally at least about 5 hours.

28. The method of claim 26 or 27, wherein said first starter compound has a molecular weight of at least about 200 Da and said second starter compound has a molecular weight of at most about 200 Da.

29. The method of any one of claims 26 to 27, wherein said second starter compound is polypropylene glycol having a molecular weight of about 200 to 1000 Da, optionally about 300 to 700 Da, optionally about 400 Da.

30. The method of any preceding claim, wherein the or each starter compound has two or more hydroxyl groups, optionally three or more, optionally four or more, optionally five or more, optionally six or more, optionally seven or more, optionally eight or more hydroxyl groups.

31. The method of any preceding claim, wherein, in mixture (a), the amount of said catalyst of formula (I) and the amount of said double metal cyanide (DMC) catalyst are at a predetermined weight ratio of from about 300:1 to about 1 :100 to one another, for example, from about 120:1 to about 1 :75, such as from about 40:1 to about 1 :50, e.g. from about 30:1 to about 1 :30 such as from about 20:1 to about 1 :1 , for example from about 10:1 to about 2:1 , e.g. from about 5:1 to about 1 :5.

32. The method of any preceding claim, wherein, in step (I), said double metal cyanide (DMC) catalyst is dry-mixed with the other components.

33. The method of any one of claims 1 to 31 , wherein, in step (I), said double metal cyanide (DMC) catalyst is mixed as a slurry, said slurry comprising the double metal cyanide (DMC) catalyst and the starter compound and/or solvent.

34. The method of any preceding claim, wherein, in step (I), said catalyst of formula (I) is dry-mixed with the other components.

35. The method of any one of claims 1 to 33, wherein, in step (I), said catalyst of formula

(I) is mixed as a solution, said solution comprising the catalyst of formula (I) and one or more of the starter compound, epoxide and/or a solvent.

36. The method of any preceding claim, wherein epoxide is added in step (II).

37. The method of any preceding claim, wherein catalyst of formula (I) is added in step

(II).

38. The method of any preceding claim, wherein double metal cyanide (DMC) catalyst is added in step (II).

39. The method of any preceding claim, wherein starter compound is added in step (II).

40. The method of any preceding claim, wherein both epoxide and starter compound are added in step (II).

41. The method of any preceding claim, wherein epoxide, catalyst of formula (I), double metal cyanide (DMC) catalyst and/or starter compound is, independently, continuously added in step (II).

42. The method of any one of claims 1 to 40, wherein epoxide, catalyst of formula (I), double metal cyanide (DMC) catalyst and/or starter compound is, independently, discontinuously added in step (II).

43. The method of any preceding claim, wherein the or each starter compound has the formula (III):

Z-( R^z)_a (III) wherein Z can be any group which can have 2 or more -R^z groups attached to it;

each R^z is independently selected from -OH, -NHR’, -SH, -C(O)OH, -P(O)(OR’)(OH), - PR’(O)(OH)₂ or -PR’(O)OH;

R’ is selected from H, or optionally substituted alkyl, heteroalkyl, aryl, heteroaryl, cycloalkyl or heterocycloalkyl; and

a is an integer which is at least 2.

44. The method of any preceding claim, wherein the or each starter compound is selected from 1 ,2-ethanediol (ethylene glycol), 1 -2-propanediol, 1 ,3-propanediol (propylene glycol), 1 ,2-butanediol, 1-3-butanediol, 1 ,4-butanediol, 1 ,5-pentanediol, 1 ,6-hexanediol, 1 ,8- octanediol, 1 ,10-decanediol, 1 ,4-cyclohexanediol, 1 ,2-diphenol, 1 ,3-diphenol, 1 ,4-diphenol, neopentyl glycol, catechol, cyclohexenediol, 1 ,4-cyclohexanedimethanol, dipropylene glycol, diethylene glycol, tripropylene glycol, triethylene glycol, tetraethylene glycol, polypropylene glycols (PPGs) or polyethylene glycols (PEGs) having an Mn of up to about 1500g/mol, such as PPG 425, PPG 725, PPG 1000 and the like;, triols such as glycerol, benzenetriol, 1 ,2,4- butanetriol, 1 ,2,6-hexanetriol, tris(methylalcohol)propane, tris(methylalcohol)ethane, tris(methylalcohol)nitropropane, trimethylol propane, polypropylene oxide triols, polyester triols, calix[4]arene, 2, 2-bis(methylalcohol)-1 , 3-propanediol, erythritol, pentaerythritol, sorbitol, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, lactic acid, glycolic acid, 3-hydroxypropanoic acid, 4-hydroxybutanoic acid, 5-hydroxypentanoic acid, ethanolamine, diethanolamine, methyldiethanolamine, and phenyldiethanolamine.

45. The method of any preceding claim, wherein the carbon dioxide is provided continuously.

46. The method of any preceding claim, wherein the method is carried out at a pressure of between about 1 bar and about 60 bar carbon dioxide, optionally about 1 bar and about 40 bar, optionally about 1 bar and about 20 bar, optionally between about 1 bar and about 15 bar, optionally about 1 bar and about 10 bar, optionally about 1 bar and about 5 bar.

47. A method for preparing a high molecular weight polyether carbonate, the method comprising the steps of:

(I) (a) mixing catalyst of formula (I), double metal cyanide (DMC) catalyst and

(d) mixing catalyst of formula (I), double metal cyanide (DMC) catalyst and optionally epoxide, carbon dioxide and/or solvent to form mixture (a); and (II) adding one or more of epoxide, carbon dioxide, catalyst of formula (I), double metal cyanide (DMC) catalyst and/or solvent to mixture (a) to form mixture (b) comprising epoxide, carbon dioxide, catalyst of formula (I), double metal cyanide (DMC) catalyst and optionally solvent,

wherein the catalyst of formula (I) has the following structure:

wherein:

M is a metal cation represented by M-(L)_V’;

(E)_m represents one or more activating groups attached to the ligand(s), where— ^ is a linker group covalently bonded to the ligand, each E is an activating functional group; and m is an integer from 1 to 4 representing the number of E groups present on an individual linker group;

v is an integer from 0 to 4; and

v’ is an integer that satisfies the valency of M, or is such that the complex

represented by formula (I) above has an overall neutral charge.

48. The method of claim 47(a) or 47(b), wherein mixture (a) is held at a temperature of between about 50 to 110°C prior to step (II), optionally between about 60 to 90°C.

49. The method of claim 47(c) or 47(d), wherein mixture (a) is held at a temperature of between about 0 to 120°C prior to step (II), optionally between about 40 to 100°C optionally between about 50 to 90°C.

50. The method of any one of claims 47 to 49, wherein mixture (a) is held for at least about 1 minute prior to step (II), optionally at least about 5 minutes, optionally at least about 15 minutes, optionally at least about 30 minutes, optionally at least about 1 hour, optionally at least about 2 hours, optionally at least about 5 hours.

51. The method of claim 47(c) or 49, wherein mixture (a) is held for at least about 5 minutes prior to step (II), optionally at least about 15 minutes, optionally at least about 30 minutes, optionally at least about 1 hour, optionally at least about 2 hours, optionally at least about 3 hours, optionally at least about 4 hours, optionally at least about 8 hours, optionally at least about 16 hours.

52. The method of any one of claims 47 to 51 , wherein mixture (a) comprises less than about 1 wt.% water, optionally less than about 0.5 wt.% water, optionally less than about 0.1 wt.% water, optionally less than about 0.05 wt.% water, optionally about 0 wt.% water.

53. The method of any one of claims 47 to 52 when dependent on claim 48(a), wherein step (I) comprises firstly mixing catalyst of formula (I), double metal cyanide (DMC) catalyst and optionally carbon dioxide to form mixture (a’), and subsequently adding epoxide and optionally carbon dioxide to form mixture (a).

54. The method of claim 53, wherein mixture (a’) is held at a temperature of between about 0 to 250°C prior to said subsequently adding, optionally about 40 to 150°C, optionally about 50 to 150°C, optionally about 70 to 140°C, optionally about 80 to 130°C.

55. The method of any one of claims 47 to 54 dependent on claim 47(c), wherein step (II) comprises mixing double metal cyanide (DMC) catalyst epoxide, and optionally carbon dioxide and/or solvent to form a pre-activated mixture and adding the pre-activated mixture to mixture (a) to form mixture (b).

56. The method of claim 55, wherein the pre-activated mixture is held at a temperature of between about 50 to 110°C prior to adding, optionally between about 60 to 90°C.

57. The method of any one of claims 47 to 56, wherein the method employs a total amount of epoxide, and wherein about 1 to 95% of the total amount of epoxide is mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

58. The method of any one of claims 47 to 57, wherein the method employs a total amount of catalyst of formula (I), and wherein about 1 to 100% of the total amount of catalyst of formula (I) is mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

59. The method of any one of claims 47 to 58, wherein the method employs a total amount of double metal cyanide (DMC) catalyst, and wherein about 1 to 100% of the total amount of double metal cyanide (DMC) catalyst mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

60. The method of any one of claims 47 to 59, wherein the method employs a total amount of carbon dioxide, and wherein about 1 to 100% of the total amount of carbon dioxide is mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

61. The method of any one of claims 47 to 60, wherein the method employs a total amount of solvent, and wherein about 1 to 100% of the total amount of solvent is mixed in step (I), with the remainder added in step (II); optionally about 1 to 75% being mixed in step (I), optionally about 1 to 50%, optionally about 1 to 40%, optionally about 1 to 30%, optionally about 1 to 20%, optionally about 5 to 20%.

62. The method of any one of claims 47 to 56, wherein the method is continuous, wherein there is a predetermined molar ratio or weight ratio of epoxide to catalyst of formula (I) in mixture (b), and wherein the method further comprises:

63. The method of any one of claims 47 to 56 or 62, wherein the method is continuous, wherein there is a predetermined molar ratio or weight ratio of carbon dioxide to catalyst of formula (I) in mixture (b), and wherein the method further comprises:

64. The method of any one of claims 47 to 56, 62 or 63, wherein the method is continuous, wherein there is a predetermined molar ratio or weight ratio of solvent to catalyst of formula (I) in mixture (b), and wherein the method further comprises:

(III) adding solvent to mixture (b) to form mixture (y), said solvent being added in an

65. The method of any one of claims 47 to 56 or 62 to 64, wherein step (III) is conducted such that the molar ratio or weight ratio of epoxide, carbon dioxide and/or solvent to catalyst of formula (I) in mixture (g) does not fall below about 75% of said predetermined molar ratio.

66. The method of claim 65, wherein step (III) is conducted such that the molar ratios or weight ratios of epoxide, carbon dioxide and solvent to catalyst of formula (I) in mixture (g) do not fall below about 75% of said predetermined molar ratios.

67. The method of any one of claims 47 to 56 or 62 to 66, wherein the method is continuous, wherein there is a predetermined amount of catalyst of formula (I) in mixture (b), and wherein the method further comprises:

68. The method of claim 67, wherein step (III) is conducted such that the amount of catalyst of formula (I) in the mixture (g) does not fall below about 50% of said predetermined amount.

69. The method of any one of claims 47 to 56 or 62 to 68, wherein the method is continuous, wherein there is a predetermined amount of double metal cyanide (DMC) catalyst in mixture (b), and wherein the method further comprises:

70. The method of claim 69, wherein step (III) is conducted such that the amount of double metal cyanide (DMC) catalyst in mixture (y) does not fall below about 50% of said predetermined amount.

71. The method of any one of claims 47 to 70, wherein, in mixture (a), the amount of said catalyst of formula (I) and the amount of said double metal cyanide (DMC) catalyst are at a predetermined weight ratio of from about 300:1 to about 1 :100 to one another, for example, from about 120:1 to about 1 :75, such as from about 40:1 to about 1 :50, e.g. from about 30:1 to about 1 :30 such as from about 20: 1 to about 1 : 1 , for example from about 10:1 to about 2:1 , e.g. from about 5:1 to about 1 :5.

72. The method of any one of claims 47 to 71 , wherein, in step (I), said double metal cyanide (DMC) catalyst is dry-mixed with the other components.

73. The method of any one of claims 47 to 72, wherein, in step (I), said double metal cyanide (DMC) catalyst is mixed as a slurry, said slurry comprising the double metal cyanide (DMC) catalyst and solvent.

74. The method of any one of claims 47 to 73, wherein, in step (I), said catalyst of formula (I) is dry-mixed with the other components.

75. The method of any one of claims 47 to 74, wherein, in step (I), said catalyst of formula (I) is mixed as a solution, said solution comprising the catalyst of formula (I) and one or more of the epoxide and/or a solvent.

76. The method of any one of claims 47 to 75, wherein epoxide is added in step (II).

77. The method of any one of claims 47 to 76, wherein catalyst of formula (I) is added in step (II).

78. The method of any one of claims 47 to 77, wherein double metal cyanide (DMC) catalyst is added in step (II).

79. The method of any one of claims 47 to 78, wherein epoxide, catalyst of formula (I) and/or double metal cyanide (DMC) catalyst is, independently, continuously added in step (II).

80. The method of any one of claims 47 to 79, wherein epoxide, catalyst of formula (I) and/or double metal cyanide (DMC) catalyst is, independently, discontinuously added in step

(II).

81. The method of any one of claims 47 to 80, wherein the carbon dioxide is provided continuously.

82. The method of any one of claims 47 to 81 , wherein the method is carried out at a pressure of between about 1 bar and about 60 bar carbon dioxide, optionally about 1 bar and about 40 bar, optionally about 1 bar and about 20 bar, optionally between about 1 bar and about 15 bar, optionally about 1 bar and about 10 bar, optionally about 1 bar and about 5 bar.

83. The method of any preceding claim, wherein M is selected from Mg, Ca, Zn, Ti, Cr, Mn, V, Fe, Co, Mo, W, Ru, Al, and Ni.

84. The method of any preceding claim, wherein

is a tetradentate ligand.

85. The method of claim 84 wherein

is a salen or salen derivative ligand, more preferably wherein

is selected from the salen or salen derivative ligands shown below, which may be optionally substituted:

salen derivatives

86. The method of claim 84, wherein is a porphyrin or porphyrin derivative

ligand, more preferably wherein is selected from the porphyrin or porphyrin

derivative ligands shown below, which may be optionally substituted:

87. The method of claim 86, wherein M is selected from Al, Cr and Co, preferably wherein M is Cr.

88. The method of any one of claims 84 to 87, wherein the tetradentate ligand is optionally substituted by one or more groups selected from halogen, hydroxy, nitro, carboxylate, carbonate, alkoxy, aryloxy, alkylthio, arylthio, heteroaryloxy, alkylaryl, amino, amido, imine, nitrile, silyl, silyl ether, ester, sulfoxide, sulfonyl, acetylide, phosphinate, sulfonate or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl groups; preferably wherein the tetradentate ligand is optionally substituted by one or more groups selected from nitro, C1 -12 alkoxy, C6-18 aryl, C2-14 heteroaryl, C2-14

heteroalicyclic, C1 -6 alkyl, C1 -6 haloalkyl, F, Cl, Br, I and OH, wherein in each of said C1 -12 alkoxy, C6-18 aryl, C2-14 heteroaryl, C2-14 heteroalicyclic, C1 -6 alkyl and C1 -6 haloalkyl group may be optionally substituted.

89. The method of any preceding claim, wherein v is 1 or more and E is a nitrogen- containing activating group, preferably wherein E is selected from

wherein each Ra is independently H; optionally substituted C1 -20 aliphatic; optionally substituted C1 -20 heteroaliphatic; optionally substituted phenyl; optionally substituted 3- to 8- membered saturated or partially unsaturated monocyclic carbocycle; optionally substituted 7- 14 carbon saturated, partially unsaturated or aromatic polycyclic carbocycle; optionally substituted 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms

wherein two or more Ra groups can be taken together with intervening atoms to form one or more optionally substituted rings optionally containing one or more additional heteroatoms; and

wherein X- is an anion.

90. The method of any preceding claim, wherein when L is present and is an anionic ligand which is capable of ring opening an epoxide, it is independently selected from

OC(O)R_x, OSO2R_X, OSOR_x, OSO(R_X)2, S(O)R_x, OR_x, acyl, phosphinate, halide, nitro, nitrate, hydroxyl, carbonate, amino, amido or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl; wherein R_x is independently hydrogen, or optionally substituted aliphatic, haloaliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl, alkylaryl or heteroaryl.

91. The method of any preceding claim, wherein when L is present and is a neutral ligand, it is independently selected from water, an alcohol, a substituted or unsubstituted heteroaryl, an ether, a thioether, a carbene, a phosphine, a phosphine oxide, a substituted or unsubstituted heteroalicyclic, an amine, an alkyl amine, acetonitrile, an ester, an acetamide, and a sulfoxide.

92. The method of any preceding claim, wherein v is 2 and/or m is 2.

93. The method of claims 84 or 85, wherein the catalyst of formula (I) has the following structure:

O2COCF₃, NO₃, OR^a and 0(C=O)R^a, wherein R^a is selected from H, optionally substituted C1 -6 alkyl, optionally substituted C1 -6 heteroalkyl, optionally substituted C6-12 aryl and optionally substituted C₃-11 heteroaryl;

L is a coordinating ligand that is capable of ring-opening an epoxide (preferably L is an anionic ligand which is capable of ring opening an epoxide), preferably wherein L is selected from 0C(O)R^x (e.g. OAc, 0C(O)CF₃, lactate, 3-hydroxypropanoate), halogen, NO₃, OSO₂R^X,

N('Pr)2 or N(SiMe3)2_, salicylate and alkyl or aryl phosphinate (e.g. dioctyl phosphinate); R^x is optionally substituted alkyl, alkenyl, alkynyl, heteroalkyl, aryl, or heteroaryl, and wherein M is as defined in claims 1 or 2, preferably wherein M is Al, Co or Cr.

94. The method of any preceding claim, wherein each occurrence of R^z may be -OH.

95. The method of any preceding claim, wherein a is an integer in the range of between about 2 and about 8, preferably in the range of about 2 and about 6.

96. The method of any preceding claim, wherein the catalyst of formula (I) is used in combination with a co-catalyst, for example, tetraalkyl ammonium salts (e.g. a tetrabutyl ammonium salt), tetraalkyl phosphinium salts (e.g. a tetrabutyl phosphonium salt), bis(triarylphosphine)iminium salts (e.g. a bis(triphenylphosphine)iminium salt), or a nitrogen containing nucleophile (e.g. methylimidazole (such as N-methyl imidazole),

97. The method of any preceding claim, wherein the DMC catalyst, in addition to at least two metal centres and cyanide ligands, also comprises at least one of: one or more complexing agents, water, a metal salt and/or an acid, optionally in non-stoichiometric amounts.

98. The method of any preceding claim, wherein the DMC catalyst is prepared by treating a solution of a metal salt with a solution of a metal cyanide salt in the presence of at least one of: complexing agent, water, and/or an acid, optionally wherein the metal salt is of the formula M’(X’)_P, wherein M’ is selected from Zn(ll), Ru(ll), Ru(lll), Fe(ll), Ni(ll), Mn(ll), Co(ll), Sn(ll), Pb(ll), Fe(lll), Mo(IV), Mo(VI), Al(lll), V(V), V(VI), Sr(ll), W(IV), W(VI), Cu(ll), and Cr(lll),

X’ is an anion selected from halide, oxide, hydroxide, sulphate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate and nitrate,

p is an integer of 1 or more, and the charge on the anion multiplied by p satisfies the valency of M’; the metal cyanide salt is of the formula (Y)_qM”(CN)_b(A)_c, wherein M” is selected from Fe(ll), Fe(lll), Co(ll), Co(lll), Cr(ll), Cr(lll), Mn(ll), Mn(lll), Ir(lll), Ni(ll), Rh(lll), Ru(ll), V(IV), and V(V),

Y is a proton or an alkali metal ion or an alkaline earth metal ion (such as K⁺),

A is an anion selected from halide, oxide, hydroxide, sulphate, cyanide oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate and nitrate;

q and b are integers of 1 or more; c may be 0 or an integer of 1 or more;

the sum of the charges on the anions Y, CN and A multiplied by q, b and c respectively (e.g. Y x q + CN x b + A x c) satisfies the valency of M”;

the at least one complexing agent is selected from a (poly)ether, a polyether carbonate, a polycarbonate, a poly(tetramethylene ether diol), a ketone, an ester, an amide, an alcohol, a urea or a combination thereof,

optionally wherein the at least one complexing agent is selected from propylene glycol, polypropylene glycol, (m)ethoxy ethylene glycol, dimethoxyethane, tert-butyl alcohol, ethylene glycol monomethyl ether, diglyme, triglyme, methanol, ethanol, isopropyl alcohol, n- butyl alcohol, isobutyl alcohol and sec-butyl alcohol, 3-buten-1-ol, 2-methyl-3-buten-2-ol, 2- methyl-3-butyn-2-ol, 3-methyl-1-pentyn-3-ol, or a combination thereof; and

wherein the acid, if present, has the formula H_rX”’, where X’” is an anion selected from halide, sulfate, phosphate, borate, chlorate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate and nitrate, and r is an integer corresponding to the charge on the counterion X’”.

99. The method of any preceding claim, wherein the DMC catalyst comprises the formula:

M’_d[M”_e(CN)_f]_g

wherein M’ and M” are as defined in claim 96, and d, e, f and g are integers, and are chosen to such that the DMC catalyst has electroneutrality,

optionally, d is 3, e is 1 , f is 6 and g is 2.

100. The method of claims 98 or 99 wherein M’ is selected from Zn(ll), Fe(ll), Co(ll) and Ni(ll), optionally wherein M’ is Zn(ll).

101. The method of claims 98 to 100 wherein M” is selected from Co(ll), Co(lll), Fe(ll), Fe(lll), Cr(lll), Ir(lll) and Ni(ll), optionally wherein M” is Co(ll) or Co(lll).

102. The method of any preceding claim, wherein the temperature of the reaction increases during the course of the method.

103. The method of any preceding claim, wherein the method is carried out on an industrial scale.

104. A product formed by the method of any preceding claim.

105. A polycarbonate ether polyol or polyether carbonate produced by a method according to any of claims 1 to 103.

106. A higher polymer produced from a polycarbonate ether polyol or polyether carbonate according to claim 105.