EP3008035A1

EP3008035A1 - Synthesis of alpha,beta-unsaturated carboxylic acid (meth)acrylates from olefins and co2

Info

Publication number: EP3008035A1
Application number: EP14725662.2A
Authority: EP
Inventors: Benjamin SCHÄFFNER; Matthias Blug; Dieter Vogt; Coen HENDRIKSEN; Evgeny PIDKO
Original assignee: Evonik Degussa GmbH
Current assignee: Evonik Operations GmbH
Priority date: 2013-06-11
Filing date: 2014-05-12
Publication date: 2016-04-20
Also published as: WO2014198469A1; CN105517986A; CA2913520A1; JP2016523855A; DE102013210840A1; US20160130208A1; BR112015031158A2

Abstract

The invention relates to a method for producing α,β-unsaturated carboxylic acids or salts thereof, comprising a step in which a metallalactone is reacted in a solvent in the presence of a halide; to a composition that comprises α,β-unsaturated carboxylic acids or salts thereof and halide ions; and to the use of said composition for the production of superabsorbent materials or as a monomer composition for producing polymers.

Description

Synthesis of α, β-unsaturated carboxylic acids (meth) acrylates from olefins and C0 ₂

The present invention is a process for the preparation of α, β-unsaturated carboxylic acids (for example acrylic or methacrylic acid) or a salt of α, β-unsaturated carboxylic acids, which comprises a process step in which a complex in a solvent in the presence of a halide is reacted, a composition comprising α, β-unsaturated carboxylic acid or its salt and halide ions, and the use of these compositions for the production of superabsorbent materials or as a monomer composition for the preparation of polymers, such as. B. polymethylmethacrylate.

To reduce climate-damaging gases, such. As carbon dioxide, numerous processes have recently been developed in which C0 _{2 is used} as a raw material for the production of popular chemical products. One method is z. For example, the preparation of acrylates by reacting carbon dioxide with olefins in the presence of a nickel bisphosphine catalyst and a base, as described by Michael L. Lejkowski et al., The First Catalytic Synthesis of acrylates from C0 ₂ and to alkenes - A Rational Approach ", Chem. Eur. J. 2012; Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim; Wiley Online Library; DOI: 10.1002 / chem.201201757. The established catalytic cycle involves the steps of converting an olefin complex with C0 ₂ to the lactone complex, converting the lactone complex to the acrylate complex, and then exchanging the acrylate ligand with the olefin ligand to give the olefin complex. When converting the lactone complex to the acrylate complex, strong bases such as sodium butanolate or NaOH are used. A disadvantage of the use of these strong bases is that in a CO2 atmosphere they tend to react with the carbon dioxide to form carbonates and thus no longer be available for the catalytic conversion. To avoid this

Side reaction must be operated relatively large effort, in which the catalytic cycle in a CO ^ rich and a CO poor part is separated. In the CO ^ rich part, the implementation of the olefin complex with C0 ₂ to the lactone complex. In the CO poor part, the conversion of the lactone complex to the acrylate complex and then the exchange of the acrylate ligand with the olefin ligand takes place. This sequential approach leads in addition to the high

As well as a significant slowdown in the reaction, since the catalytic process is achieved only gradually. Already in WO 201 1/107559 Limbach et al., Who was also involved in the above-mentioned publication as a writer, described processes for the preparation of an alkali metal or alkaline earth metal salt of an α, β-ethylenically unsaturated carboxylic acid, where a) an alkene , Converts the carbon dioxide and a carboxylation catalyst to an alkene / carbon dioxide / carboxylation catalyst adduct, b) the adduct decomposes with the release of the carboxylation catalyst with an auxiliary base to the auxiliary base salt of the α, β-ethylenically unsaturated carboxylic acid, c) the auxiliary base salt of the α, β-ethylenically unsaturated carboxylic acid with the release of the auxiliary base with an alkali or alkaline earth metal base to the alkali or alkaline earth metal salt of the α, β-ethylenically unsaturated carboxylic acid.

As auxiliary bases in WO 201 1/107559 z. B. anion bases, such as. Salts with inorganic or organic ammonium ions or alkali or alkaline earth metals, or neutral bases, inorganic anion bases including carbonates, phosphates, nitrates or halides and organic anion bases including phenolates, carboxylates, sulfates organic molecular units, sulfonates, phosphates, phosphonates can be and organic neutral bases may be, inter alia, primary, secondary or tertiary amines, furthermore ethers, esters, imines, amides, carbonyl compounds, carboxylates or carbon monoxide. The auxiliary base used is preferably a primary, secondary or tertiary amine, more preferably a tertiary amine.

A disadvantage of using the amines as auxiliary bases is that the auxiliary bases must be removed again in one or more steps. This is preferably done using alkali metal carbonates, hydroxides or oxides, preferably sodium hydroxide.

Another publication by Bernskoetter et al. "Lewis Acid Induced β-Elimination from a Nickel Alactone: Efferts toward Acrylate Production from C0 ₂ and Ethylene" (Organometallics, 2013, DOI: 10.1021 / om400025h) describes the synthesis of acrylates starting from strong (Lewis) acids such as tris (pentafluorophenyl) This compound was used in the working group to achieve additional activation of the nickelalactone.

This allowed the cycle to be disrupted and finally the acrylate attached to the complex. A disadvantage is the use of tris (pentafluorophenyl) borane. The access to these compounds is complex and not given on a large scale. In addition, the reaction was carried out step by step and the previously required for the implementation Nickelalactonkomplex previously synthesized separately. A complete implementation of the catalytic cycle has thus not taken place. The object of the present invention was to provide a process for the preparation of α, β-unsaturated carboxylic acids such. B. (meth) acrylates of olefins and C0 ₂ , which avoids one or more disadvantages of existing methods of the prior art.

Surprisingly, it has been found that the addition of salts from the group of alkali metal halides to the reaction mixture, the reaction described above can also be catalyzed. It was found that simple halides, in particular iodides such as lithium iodide, sodium iodide or potassium iodide can act as Lewis acid to destabilize or split the formed nickel alactone.

Advantageous over the method of Limbach et al. is in particular that all iodides used have only a low basicity and thus no CO bond to carbonates takes place, as is the case for strong bases (eg sodium butanolate or lithium hexamethyldisilazane (LiHMDS)). Compared to the Lewis acid tris (pentafluorophenyl) borane described above, the halides used are characterized by easy accessibility and easier handling, even when using large amounts. Since the compounds are stable even in a wider temperature range, these salts can be more easily separated and reused.

In addition, simple ammonium iodides such as tetrabutylammonium iodide are also suitable for the reaction. Last but not least, the use of sodium iodide as a salt and Lewis acid can lead directly to the formation of sodium acrylate, a precursor for the synthesis of superabsorbents.

The process according to the invention has the particular advantage that the synthesis of α, β-unsaturated carboxylic acids or their salts can be carried out directly from the starting materials of an olefin and C0 ₂ without isolation of special intermediates. The process according to the invention, the composition according to the invention and the use thereof are described below by way of example, without the invention being restricted to these exemplary embodiments. Given below, ranges, general formulas, or classes of compounds are intended to encompass not only the corresponding regions or groups of compounds explicitly mentioned, but also all sub-regions and sub-groups of compounds obtained by removing individual values (ranges) or compounds can be. If documents are cited in the context of the present description, their content, in particular with regard to the matters referred to, should form part of the disclosure content of the present invention. If the following information is given as a percentage, it is, unless stated otherwise, in% by weight. If mean values are given below, this is the number average, unless otherwise stated. Are below material properties such. As viscosities or the like, it is, unless otherwise stated, the material properties at 25 ° C. In the present invention, when chemical (sum) rolls are used, the indices given may represent both absolute numbers and average values. [0022] In the case of polymeric compounds, the indices are preferably average values. If in the present application the term "(meth) acrylic acid" or ( Meth) acrylate is to be understood as meaning both methacrylic acid and acrylic acid or both methacrylate and acrylate The process according to the invention for the production of α, β-unsaturated carboxylic acids or a salt of the α, β-unsaturated carboxylic acid, preferably (meth) acrylic acid or a salt of (meth) acrylic acid, preferably acrylic acid or a salt of acrylic acid, is characterized in that it comprises a process step in which, preferably intermediately (or in the meantime), a substance of the formula (I)

With

E = element of groups 4, 6, 7, 8, 9 or 10 of the Periodic Table of the Elements, preferably nickel,

L = nitrogen or phosphorus-containing, preferably bidentate phosphoric ligand, n = 1 to 4, preferably 1,

R is H or an aryl or alkyl radical, preferably H or a branched or unbranched alkyl radical having 1 to 10 carbon atoms, particularly preferably H or a methyl group and very particularly preferably H,

in a solvent in the presence of a halide, preferably selected from the group of alkali earth alkaline and ammonium halides, is reacted. The halides used are preferably Nal, LiCl, Lil and (nBu) ₄ NI. Particularly preferred halides are iodides, in particular Nal and / or Lil. In the process according to the invention, L is preferably a ligand selected from phosphanes or phosphonates, preferably bisphosphanes or bisphosphonates, preferably selected from trialkyl, dialkyl-aryl, alkyl-diaryl and triaryl-bisphosphane ligands. Most preferably, L is selected from bis (dicyclohexylphosphino) ethane (Dcpe), bis (di-tert-butylphosphino) ethane and bis (diphenylphosphino) ethane.

As solvents, it is possible to use all known solvents, preferably the solvent is selected from halogenated hydrocarbons, halogenated aromatics and cyclic ethers, preferably chlorobenzene or dichloromethane or tetrahydrofuran. Chloroform, dichloromethane or chlorobenzene, preferably chlorobenzene, is particularly preferably used as the solvent.

In the process according to the invention, the process step is very particularly preferably carried out in such a way that a substance of the formula (I) where E = nickel (Ni °), n = 1, L = bis (diphenylphosphino) ethane or bis (dicyclohexylphosphino) ethane in one Solvent, preferably chlorobenzene, dichloromethane or tetrahydrofuran, preferably chlorobenzene, in the presence of a iodide selected from Nal, Lil and (nBu) ₄ NI is reacted. The reaction can be carried out at atmospheric pressure or elevated pressure. The reaction of the compound of the formula (I) (of the nickelalactone) is preferably carried out at partial pressures of from 1 to 50 bar C0 ₂ and from 1 to 50 bar of the corresponding olefin.

The reaction can be carried out at any temperature. Preferably, the reaction is carried out at a temperature of 0 to 150 ° C, preferably 15 to 100 ° C and more preferably at a temperature of 25 to 60 ° C.

The molar ratio of halide ions to element E is preferably from 0.1 to 1 to 50 to 1, preferably from 1 to 1 to 20 to 1.

It may be advantageous if the substance of the formula (I) by reaction of a

Complex compound of the formula (II)

EL _n (II)

with E, L and n as defined above, with an olefin and carbon dioxide. The olefins used are preferably hydrocarbons which have at least one unsaturated carbon-carbon bond. Preferred olefins are those Hydrocarbons used which have 1 to 10 carbon atoms. Particular preference is given to using ethene or propene as olefins, ethene being very particularly preferred. This implementation can z. Example, as in Michael L. Lejkowski et al., "The First Catalytic Synthesis of an acrylate from C0 ₂ and to alkenes - A Rational Approach", Chem. Eur. J. 2012; Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim; Wiley Online Library; DOI: 10.1002 / chem.201201757. In addition, a simple method of preparation of the compound of formula (I) is in an article by Heinz Hoberg and Dietmar Schäfer "Nickel (0) -induced CC linkage between carbon dioxide and ethylene and mono- or di-substituted alkenes" J. Organomet. Chem., 1983, 251, C51-C53 (Elsevier Sequoia).

Preferably, nickel (1, 5-cyclooctadiene) 2 (Ni (cod) 2) is used for the preparation of the compound of formula (I) and ligand L, preferably 1, 2-bis (dicyclohexylphosphino) ethane, bis (di-) tert-butylphosphino) ethane or

Dissolved bis (diphenylphosphino) ethane in tetrahydrofuan. Subsequently, olefin, preferably ethene or propene, preferably ethene and C0 _{2 is} added. The molar ratio of the compounds to one another is complex compound of the formula (II): C0 ₂ : Olefin, preferably ethene = 1: 1: 5. After removal of tetrahydrofuran, the compound of the formula (I) can be obtained as a yellow-green compound in 50% yield ,

Preference is given to the substance of the formula (I) by direct reaction of a catalyst precursor of the element E with a preferably bidentate phosphane or phosphonate ligand in a halogenated solvent or cyclic ether in a

C0 ₂ / olefin atmosphere, preferably a C0 ₂ / ethene or C0 ₂ / propene atmosphere, preferably prepared in a C0 ₂ / ethene atmosphere.

Particular preference is given to a complex compound of the formula (II) where E = nickel (Ni °), n = 2 and L = bis (diphenylphosphino) ethane or bis (dicyclohexylphosphino) ethane, preferably

Bis (dicyclohexylphosphino) ethane with an olefin, preferably ethene or propene, preferably ethene and carbon dioxide with a molar ratio of 10/40 at 1 to 75 bar, preferably 30 to 60 bar, preferably about 50 bar in chlorobenzene, dichloromethane or tetrahydrofuran, preferably chlorobenzene, reacted at 30 to 60 ° C. The inventive compositions are obtainable, the halide ions and α, β-unsaturated carboxylic acid, preferably (meth) acrylic acid, particularly preferably acrylic acid or its salts (with alkali, alkaline earth metal ammonium), in particular the inventive compositions described below ,

The compositions according to the invention containing the α, β-unsaturated carboxylic acid or its salt are characterized in that they have halide ions, preferably iodide ions. The proportion of halide ions, preferably iodide ions, is preferably from 20 to 1000 mol%, preferably from 50 to 500 mol%, based on the substance of the formula (I).

Even in the case of compositions according to the invention obtained by a process according to the invention in which the substance of the formula (I) is not isolated, the compositions according to the invention have .alpha.,. Beta.-unsaturated carboxylic acid or a salt thereof and a halide ion, preferably iodide ions , on. The proportion of halide ions, preferably iodide ions, is preferably 50 to 5000 mol%, preferably 100 mol% to 500 mol%, based on E before. In this method, preference is given to using ligands L which are selected from the group comprising bis (dicyclohexylphosphino) ethane and bis (di-tert-butylphosphino) ethane (d'Bupe). The determination of the content of E, can be carried out by known suitable analytical methods. Represents E z. As nickel, the nickel content z. B. by atomic absorption spectrometry (AAS) at 232.0 nm, z. As in Welz, B .; Sperling, M., atomic absorption spectrometry, Wiley-VHC: Weinheim, (1997); P. 565, described. The halide determination can be carried out by known suitable analytical methods. The determination of chloride, iodide and bromide is preferably carried out by the method "Titration Volhard", as in known

Textbooks of chemistry is described.

The compositions according to the invention, in particular those which contain acrylic acid or salts thereof, may, for. For the production of superabsorbent materials or as monomer compositions for the preparation of polymers. The

Preparation of such polymers or superabsorbent materials may e.g. The book "Modem Superabsorbent Polymer Technology", John Wiley &Sons; Edition: 1st edition (11 December 1997), ISBN 13: 978-0471 1941 18. The compositions of the invention, in particular those containing methacrylic acid or salts thereof, may, for. B. for the production of polymethylmethacrylates and semifinished products or plates produced therefrom. In the examples given below, the present invention is described by way of example, without the invention, the scope of application of which is apparent from the entire description and the claims, to be limited to the embodiments mentioned in the examples.

Examples:

Measurement method:

1 1 ^ 1

H, C and P-NMR spectra were recorded at room temperature by means of an NMR spectrometer (Avance III, 400 MHz, Bruker). All spectra were referenced by TMS or by the solvent peak of the deuterated solvent. Infrared measurements were taken with an IR spectrometer (2000 FT-IR, Perkin-Elmer). Acrylic acid was detected by GC using a gas chromatograph Shimadzu GC-2010 (Shimadzu) and a CP-Wax (ffap) cb column (Agilent).

Example 1: Preparation of a substance of the formula (I) for decomposition experiments

300 mg (1.21 mmol) of tetramethylethylenediamine nickelalactone were dissolved in 15 ml of tetrahydrofuran under an inert gas atmosphere in a glass flask, and 488.8 mg (1.23 mmol) of diphenyldiphosphinoethane were added. The yellow suspension was then stirred at 22 ° C for 16 h. Subsequently, the solvent was removed in vacuo and the remaining yellow solid was washed 5 times with 10 mL of tetrahydrofuran. Subsequently, the product was dried in vacuo. Example 2: In situ production of a substance of formula (I) for catalytic experiments with simultaneous reaction in acrylic acid

In a 4 mL magnetic stirrer reactor, 13.5 mg (0.049 mmol) of nickel (1, 5-cyclooctadiene) ₂ (Ni (cod) ₂ ) was added 0.049 mmol of the corresponding ligand (1 equivalent) and 0.25 mmol (5 equivalents) of halide salt mixed with 2 mL of solvent and then placed in an autoclave. The pressure of the autoclave was used at 10 bar of ethylene. After one hour, the pressure was adjusted to 50 bar C0 ₂ and the system was heated to 50 ° C. After 96 hours, the pressure was removed and the mixture of substances was analyzed. For this, the reaction was stopped by the addition of 0.02 ml of trifluoroacetic acid and converted unreacted Nickelalacton in free propionic acid. The reaction mixture was dissolved in 1.0 mL of tetrahydrofuran and treated with 1 mg of acetic acid in 0.5 mL of tetrahydrofuran (internal standard). The mixture was filtered through silica gel and analyzed by GC and NMR. Example 3: Reaction of a substance of the formula (I) in a solvent in the presence of a halide In a reaction vessel with a total volume of 2 mL was added under an inert gas atmosphere to a solution consisting of 1 mL dichloromethane (DCM) and 13.3 mg (0.025 mmol) (diphenylphosphinoethane) Ni (C ₃ H ₄ O 2) (I) became 5 , 3 mg (0.125 mmol) of lithium chloride. Subsequently, the mixture was stirred at 22 ° C for 20 hours. Subsequently, the substance mixture was worked up and analyzed according to Example 2.

Analogous to Example 3, further investigations of the decomposition reaction were carried out by varying the salt and solvent at 50 ° C. according to Table 1. The results for the decomposition reaction of the substance of formula (I) with E = nickel (Ni °), n = 1, L = bis (diphenylphosphino) ethane using different salts and solvents are shown in Table 1.

Table 1: Variation of the solvent and the salts at 50 ° C according to Example 3.

Relative GC peaks were determined by correlation between acrylate and ropionate with acetic acid as internal standard. Analogous to Example 3, further investigations of the decomposition reaction were carried out by varying the salt and solvent at 22 ° C. according to Table 2. The results for the decomposition reaction of the substance of the formula (I) with E = nickel (Ni °), n = 1, L = bis (diphenylphosphino) ethane using different salts and solvents are shown in Table 2. Table 2: Variation of the solvent and the salts at 22 ° C according to Example 3.

a Relative GC peaks were determined by correlation between acrylate and propionate with acetic acid as internal standard.

Analogous to Example 3, further investigations of the decomposition reaction were carried out by varying the salt and solvent at 100 ° C. according to Table 3. The results for the decomposition reaction of the substance of the formula (I) with E = nickel (Ni °), n = 1, L = bis (diphenylphosphino) ethane using different salts and solvents are shown in Table 3. Table 3: Variation of the solvent and the salts at 100 ° C according to Example 3.

In the experiments at elevated temperature showed that the best results can be achieved with halide-containing salts, in particular with iodides, while only comparatively low yields of acrylates were obtained with the comparatively used triflates (OTf). In this case, only halide-free solvents such as alcohols or ethers such as tetrahydrofuran were used.

Analogous to Example 3, further investigations of the decomposition reaction by varying the salt were carried out according to Table 4 at 22 ° C. The results for the decomposition reaction of the substance of formula (I) with E = nickel (NiO), n = 1, L = bis (diphenylphosphino) ethane used with different salts using dichloromethane (DCM).

Table 4: Variation of the salts in dichloromethane at 22 ° C according to Example 3.

Relative GC 'peaks were determined by correlation between acrylate and propionate with acetic acid as internal standard. In the experiments, the particular suitability of halides, especially iodides clearly. By using lithium iodide or tetrabutylammonium iodide (TBAI), high acrylate yields could already be achieved at room temperature. In addition, halogenated solvents are preferred for the reaction.

Due to the low suitability of dichloromethane as a solvent in large-scale industrial applications, experiments were carried out with chlorobenzene as a solvent.

Analogously to Example 2, experiments were carried out according to Table 5 for the in situ formation of acrylic acid starting from the starting materials. In this case, the corresponding intermediate (I) was not isolated but converted by addition of the halide directly into the acrylate.

Table 5: Variation of the salts in chlorobenzene at 50 ° C for the in situ experiments according to Example 2.

From the results in Table 5 it can be seen that in halogenated solvents a direct conversion of ethylene and C0 ₂ via the intermediate formed in situ (I) in the presence of lithium chloride and lithium iodide is possible.

Claims

claims:

1. Process for the preparation of α, β-unsaturated carboxylic acids or their salts, characterized in that it comprises a process step in which a substance of the formula (I)

With

E = element of groups 4, 6, 7, 8, 9 or 10 of the Periodic Table of the Elements,

L = nitrogen- or phosphorus-containing ligand

n = 1 to 4, preferably 1,

R = H or an aryl or alkyl radical,

is reacted in a solvent in the presence of a halide.

A method according to claim 1, characterized in that R in formula (I) is H or an alkyl radical having 1 to 10 carbon atoms.

A method according to claim 1 and 2, characterized in that R in formula (I) is H or a methyl radical, preferably H.

A method according to claim 1 to 3, characterized in that E in formula (I) is nickel. 5. The method according to claim 1 or 4, characterized in that L is a bidentate ligand.

Process according to at least one of Claims 1 to 5, characterized in that L is a bisphosphane or bisphosphonate ligand, preferably selected from trialkyl, dialkylaryl, akyl-diaryl, triaryl-bisphosphane ligands.

Method according to at least one of claims 1 to 6, characterized in that the L is a ligand selected from bis (di-tert-butylphosphino) ethane, bis (dicyclohexylphosphino) ethane or bis (diphenylphosphino) ethane.

8. The method according to at least one of claims 1 to 7, characterized in that the halide is an iodide. 9. The method according to at least one of claims 1 to 8, characterized in that the halide is selected from Nal, Lil and (nBu) ₄ NI.

10. The method according to at least one of claims 1 to 9, characterized in that the solvent is selected from cyclic ethers, chlorinated aromatics and aliphatic chlorohydrocarbons, more preferably chloroform, chlorobenzene and dichloromethane.

1 1. The method according to at least one of claims 1 to 10, characterized in that the compound of formula (I) by reacting a complex compound of the formula (II)

EL _n (II) with E, L and n as defined in any one of the preceding claims

is obtained with an olefin and carbon dioxide. 12. The method according to claim 1 1, characterized in that the method without

Isolation of the compound of formula (I) is performed.

13. The method of claim 10 or 1 1, characterized in that is used as the olefin propene or ethene, preferably ethene.

Composition comprising E, an α, β-unsaturated carboxylic acid or its salt, characterized in that it comprises halide ions, with E as defined in any one of the preceding claims.

15. The composition according to claim 14, characterized in that the α, β-unsaturated carboxylic acid or its salt is acrylic acid or methacrylic acid or its salts, preferably acrylic acid or its salt.

16. The composition according to claim 14 or 15, characterized in that the proportion of iodide ions from 20 to 1000 mol .-% based on 100 mol .-% E is.

17. The composition of claim 14 to 16, characterized in that the proportion of the α, β-unsaturated carboxylic acid or its salt from 2 to 100 wt .-% based on the composition less the amount of halide ions, solvents, E and L. , with L as defined in any one of the preceding claims.

18. Use of a composition according to at least one of the claims

16 for the production of superabsorbent materials or monomer composition for the production of polymers.