WO2020120936A1 - Compounds suitable for use in the polymerisation of cyclic esters - Google Patents
Compounds suitable for use in the polymerisation of cyclic esters Download PDFInfo
- Publication number
- WO2020120936A1 WO2020120936A1 PCT/GB2019/053446 GB2019053446W WO2020120936A1 WO 2020120936 A1 WO2020120936 A1 WO 2020120936A1 GB 2019053446 W GB2019053446 W GB 2019053446W WO 2020120936 A1 WO2020120936 A1 WO 2020120936A1
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- WO
- WIPO (PCT)
- Prior art keywords
- alkyl
- compound
- group
- heteroaryl
- alkoxy
- Prior art date
Links
- 150000001875 compounds Chemical class 0.000 title claims abstract description 82
- 125000004122 cyclic group Chemical group 0.000 title claims abstract description 16
- 238000000034 method Methods 0.000 claims abstract description 20
- 150000002596 lactones Chemical class 0.000 claims abstract description 8
- 125000000217 alkyl group Chemical group 0.000 claims description 77
- 125000001072 heteroaryl group Chemical group 0.000 claims description 40
- 125000003118 aryl group Chemical group 0.000 claims description 35
- 125000003545 alkoxy group Chemical group 0.000 claims description 29
- -1 amino, hydroxy Chemical group 0.000 claims description 21
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 claims description 20
- WVDDGKGOMKODPV-UHFFFAOYSA-N Benzyl alcohol Chemical compound OCC1=CC=CC=C1 WVDDGKGOMKODPV-UHFFFAOYSA-N 0.000 claims description 18
- 125000004104 aryloxy group Chemical group 0.000 claims description 17
- 238000007151 ring opening polymerisation reaction Methods 0.000 claims description 13
- 125000003342 alkenyl group Chemical group 0.000 claims description 9
- 125000000951 phenoxy group Chemical group [H]C1=C([H])C([H])=C(O*)C([H])=C1[H] 0.000 claims description 8
- 235000019445 benzyl alcohol Nutrition 0.000 claims description 6
- 239000012190 activator Substances 0.000 claims description 5
- 125000001797 benzyl group Chemical group [H]C1=C([H])C([H])=C(C([H])=C1[H])C([H])([H])* 0.000 claims description 5
- 125000005553 heteroaryloxy group Chemical group 0.000 claims description 5
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 claims description 5
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 claims description 4
- DKGAVHZHDRPRBM-UHFFFAOYSA-N Tert-Butanol Chemical compound CC(C)(C)O DKGAVHZHDRPRBM-UHFFFAOYSA-N 0.000 claims description 4
- 229910052801 chlorine Inorganic materials 0.000 claims description 3
- JJTUDXZGHPGLLC-UHFFFAOYSA-N lactide Chemical group CC1OC(=O)C(C)OC1=O JJTUDXZGHPGLLC-UHFFFAOYSA-N 0.000 claims description 3
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical group [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims description 2
- 229910052735 hafnium Chemical group 0.000 claims description 2
- VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical group [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 claims description 2
- 229960004592 isopropanol Drugs 0.000 claims description 2
- 229910052726 zirconium Inorganic materials 0.000 claims description 2
- 125000001475 halogen functional group Chemical group 0.000 claims 10
- 239000002904 solvent Substances 0.000 description 15
- 125000005843 halogen group Chemical group 0.000 description 14
- UHOVQNZJYSORNB-MZWXYZOWSA-N benzene-d6 Chemical group [2H]C1=C([2H])C([2H])=C([2H])C([2H])=C1[2H] UHOVQNZJYSORNB-MZWXYZOWSA-N 0.000 description 13
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 12
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 11
- 238000006243 chemical reaction Methods 0.000 description 10
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 9
- OFBQJSOFQDEBGM-UHFFFAOYSA-N Pentane Chemical compound CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 8
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Natural products CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 8
- 230000015572 biosynthetic process Effects 0.000 description 8
- 125000004432 carbon atom Chemical group C* 0.000 description 8
- 238000003786 synthesis reaction Methods 0.000 description 8
- 239000013078 crystal Substances 0.000 description 7
- 238000000425 proton nuclear magnetic resonance spectrum Methods 0.000 description 7
- 239000007787 solid Substances 0.000 description 7
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 6
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 6
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 6
- 238000005481 NMR spectroscopy Methods 0.000 description 5
- 238000002360 preparation method Methods 0.000 description 5
- 229910052796 boron Inorganic materials 0.000 description 4
- 125000005842 heteroatom Chemical group 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 238000005160 1H NMR spectroscopy Methods 0.000 description 3
- YBYIRNPNPLQARY-UHFFFAOYSA-N 1H-indene Natural products C1=CC=C2CC=CC2=C1 YBYIRNPNPLQARY-UHFFFAOYSA-N 0.000 description 3
- 238000002441 X-ray diffraction Methods 0.000 description 3
- 125000000304 alkynyl group Chemical group 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical group [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 125000002619 bicyclic group Chemical group 0.000 description 3
- 239000003054 catalyst Substances 0.000 description 3
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 3
- 239000003999 initiator Substances 0.000 description 3
- MZRVEZGGRBJDDB-UHFFFAOYSA-N n-Butyllithium Substances [Li]CCCC MZRVEZGGRBJDDB-UHFFFAOYSA-N 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N nitrogen Substances N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000001301 oxygen Chemical group 0.000 description 3
- 238000001953 recrystallisation Methods 0.000 description 3
- 125000001424 substituent group Chemical group 0.000 description 3
- 238000004009 13C{1H}-NMR spectroscopy Methods 0.000 description 2
- JJTUDXZGHPGLLC-IMJSIDKUSA-N 4511-42-6 Chemical compound C[C@@H]1OC(=O)[C@H](C)OC1=O JJTUDXZGHPGLLC-IMJSIDKUSA-N 0.000 description 2
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical group [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- HEDRZPFGACZZDS-MICDWDOJSA-N Trichloro(2H)methane Chemical compound [2H]C(Cl)(Cl)Cl HEDRZPFGACZZDS-MICDWDOJSA-N 0.000 description 2
- 229910007928 ZrCl2 Inorganic materials 0.000 description 2
- 238000013019 agitation Methods 0.000 description 2
- 239000011203 carbon fibre reinforced carbon Substances 0.000 description 2
- ZMMRKRFMSDTOLV-UHFFFAOYSA-N cyclopenta-1,3-diene zirconium Chemical compound [Zr].C1C=CC=C1.C1C=CC=C1 ZMMRKRFMSDTOLV-UHFFFAOYSA-N 0.000 description 2
- 238000000921 elemental analysis Methods 0.000 description 2
- 150000002148 esters Chemical class 0.000 description 2
- 239000000706 filtrate Substances 0.000 description 2
- 229910052736 halogen Inorganic materials 0.000 description 2
- 150000002367 halogens Chemical class 0.000 description 2
- 239000003446 ligand Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 125000002950 monocyclic group Chemical group 0.000 description 2
- SYSQUGFVNFXIIT-UHFFFAOYSA-N n-[4-(1,3-benzoxazol-2-yl)phenyl]-4-nitrobenzenesulfonamide Chemical class C1=CC([N+](=O)[O-])=CC=C1S(=O)(=O)NC1=CC=C(C=2OC3=CC=CC=C3N=2)C=C1 SYSQUGFVNFXIIT-UHFFFAOYSA-N 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 230000035484 reaction time Effects 0.000 description 2
- 229910052717 sulfur Chemical group 0.000 description 2
- 239000011593 sulfur Chemical group 0.000 description 2
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 2
- CTPDSKVQLSDPLC-UHFFFAOYSA-N 2-(oxolan-2-ylmethoxy)ethanol Chemical compound OCCOCC1CCCO1 CTPDSKVQLSDPLC-UHFFFAOYSA-N 0.000 description 1
- 125000003903 2-propenyl group Chemical group [H]C([*])([H])C([H])=C([H])[H] 0.000 description 1
- 238000004286 7Li NMR spectroscopy Methods 0.000 description 1
- MKYBYDHXWVHEJW-UHFFFAOYSA-N N-[1-oxo-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propan-2-yl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(C(C)NC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 MKYBYDHXWVHEJW-UHFFFAOYSA-N 0.000 description 1
- YBGCOFSXTRUWOR-UHFFFAOYSA-N [Th]CC1=CC=CC=C1 Chemical compound [Th]CC1=CC=CC=C1 YBGCOFSXTRUWOR-UHFFFAOYSA-N 0.000 description 1
- 239000008186 active pharmaceutical agent Substances 0.000 description 1
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 description 1
- 125000004429 atom Chemical group 0.000 description 1
- 229910052794 bromium Inorganic materials 0.000 description 1
- 125000001246 bromo group Chemical group Br* 0.000 description 1
- 125000004369 butenyl group Chemical group C(=CCC)* 0.000 description 1
- 125000000484 butyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 125000000480 butynyl group Chemical group [*]C#CC([H])([H])C([H])([H])[H] 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 125000001309 chloro group Chemical group Cl* 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000000599 controlled substance Substances 0.000 description 1
- 125000000058 cyclopentadienyl group Chemical group C1(=CC=CC1)* 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 230000005595 deprotonation Effects 0.000 description 1
- 238000010537 deprotonation reaction Methods 0.000 description 1
- 239000011903 deuterated solvents Substances 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 238000012377 drug delivery Methods 0.000 description 1
- ZSWFCLXCOIISFI-UHFFFAOYSA-N endo-cyclopentadiene Natural products C1C=CC=C1 ZSWFCLXCOIISFI-UHFFFAOYSA-N 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 238000001640 fractional crystallisation Methods 0.000 description 1
- 125000006038 hexenyl group Chemical group 0.000 description 1
- 125000004051 hexyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 125000005980 hexynyl group Chemical group 0.000 description 1
- 238000001727 in vivo Methods 0.000 description 1
- 125000003454 indenyl group Chemical group C1(C=CC2=CC=CC=C12)* 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 229910052740 iodine Inorganic materials 0.000 description 1
- 125000001449 isopropyl group Chemical group [H]C([H])([H])C([H])(*)C([H])([H])[H] 0.000 description 1
- JVTAAEKCZFNVCJ-UHFFFAOYSA-N lactic acid Chemical group CC(O)C(O)=O JVTAAEKCZFNVCJ-UHFFFAOYSA-N 0.000 description 1
- DLEDOFVPSDKWEF-UHFFFAOYSA-N lithium butane Chemical compound [Li+].CCC[CH2-] DLEDOFVPSDKWEF-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 125000004108 n-butyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 125000004123 n-propyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 125000001624 naphthyl group Chemical group 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 150000002902 organometallic compounds Chemical class 0.000 description 1
- 125000002524 organometallic group Chemical group 0.000 description 1
- 125000002255 pentenyl group Chemical group C(=CCCC)* 0.000 description 1
- 125000001147 pentyl group Chemical group C(CCCC)* 0.000 description 1
- 125000005981 pentynyl group Chemical group 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 238000006068 polycondensation reaction Methods 0.000 description 1
- 125000003367 polycyclic group Chemical group 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 125000004368 propenyl group Chemical group C(=CC)* 0.000 description 1
- 125000001436 propyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 125000002568 propynyl group Chemical group [*]C#CC([H])([H])[H] 0.000 description 1
- JUJWROOIHBZHMG-RALIUCGRSA-N pyridine-d5 Chemical compound [2H]C1=NC([2H])=C([2H])C([2H])=C1[2H] JUJWROOIHBZHMG-RALIUCGRSA-N 0.000 description 1
- 239000011541 reaction mixture Substances 0.000 description 1
- 125000002914 sec-butyl group Chemical group [H]C([H])([H])C([H])([H])C([H])(*)C([H])([H])[H] 0.000 description 1
- 238000004467 single crystal X-ray diffraction Methods 0.000 description 1
- 239000012453 solvate Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 125000000999 tert-butyl group Chemical group [H]C([H])([H])C(*)(C([H])([H])[H])C([H])([H])[H] 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 125000003944 tolyl group Chemical group 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- PAPBSGBWRJIAAV-UHFFFAOYSA-N ε-Caprolactone Chemical compound O=C1CCCCCO1 PAPBSGBWRJIAAV-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
- C08G63/06—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from hydroxycarboxylic acids
- C08G63/08—Lactones or lactides
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
- C07F17/00—Metallocenes
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
- C07F5/00—Compounds containing elements of Groups 3 or 13 of the Periodic Table
- C07F5/02—Boron compounds
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/78—Preparation processes
- C08G63/82—Preparation processes characterised by the catalyst used
- C08G63/823—Preparation processes characterised by the catalyst used for the preparation of polylactones or polylactides
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/78—Preparation processes
- C08G63/82—Preparation processes characterised by the catalyst used
- C08G63/85—Germanium, tin, lead, arsenic, antimony, bismuth, titanium, zirconium, hafnium, vanadium, niobium, tantalum, or compounds thereof
Definitions
- the present invention relates to compounds that are suitable for use in the polymerisation of cyclic esters, such as lactides and lactones. More specifically, the present invention relates to ansa-metallocene compounds that are suitable for this use. The invention also relates to a process for the ring opening polymerisation (ROP) of cyclic esters, such as lactides and lactones.
- ROP ring opening polymerisation
- PLAs Poly(lactic acids)
- PLAs Poly(lactic acids)
- PLAs are both biodegradable and biocompatible, they are of equal value to the field of medicine, wherein their versatile physical properties make them suitable for in vivo applications (e.g. as media for controlled drug delivery devices).
- a process for the ring opening polymerisation (ROP) of a cyclic ester comprising the step of contacting a compound according to the first aspect with one or more cyclic esters.
- (m-nC) or "(m-nC) group” used alone or as a prefix, refers to any group having m to n carbon atoms.
- alkyl refers to straight or branched chain alkyl moieties, typically having 1 , 2, 3, 4, 5 or 6 carbon atoms. This term includes reference to groups such as methyl, ethyl, propyl (n-propyl or isopropyl), butyl (n-butyl, sec-butyl or tert-butyl), pentyl, hexyl and the like. In particular, an alkyl may have 1 , 2, 3 or 4 carbon atoms.
- alkenyl refers to straight or branched chain alkenyl moieties, typically having 1 , 2, 3, 4, 5 or 6 carbon atoms.
- This term includes reference to groups such as ethenyl (vinyl), propenyl (allyl), butenyl, pentenyl and hexenyl, as well as both the cis and trans isomers thereof.
- alkynyl refers to straight or branched chain alkynyl moieties, typically having 1 , 2, 3, 4, 5 or 6 carbon atoms.
- the term includes reference to alkynyl moieties containing 1 , 2 or 3 carbon-carbon triple bonds (CoC). This term includes reference to groups such as ethynyl, propynyl, butynyl, pentynyl and hexynyl.
- alkoxy refers to -O-alkyl, wherein alkyl is straight or branched chain and comprises 1 , 2, 3, 4, 5 or 6 carbon atoms.
- alkoxy has 1 , 2, 3 or 4 carbon atoms. This term includes reference to groups such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, tert-butoxy, pentoxy, hexoxy and the like.
- aryl or“aromatic” as used herein means an aromatic ring system comprising 6, 7, 8, 9 or 10 ring carbon atoms.
- Aryl is often phenyl but may be a polycyclic ring system, having two or more rings, at least one of which is aromatic. This term includes reference to groups such as phenyl, naphthyl and the like. A particularly suitable aryl group is phenyl.
- aryl(m-nC)alky refers to group -(CH 2 )m-n-aryl, wherein aryl has any of definitions outlined above.
- a particular aryl(m-nC)alkyl group is benzyl.
- aryloxy refers to -O-aryl, wherein aryl has any of the definitions discussed herein.
- heteroaryl or“heteroaromatic” means an aromatic mono-, bi-, or polycyclic ring incorporating one or more (for example 1-4, particularly 1 , 2 or 3) heteroatoms selected from nitrogen, oxygen or sulfur.
- heteroaryl groups are monocyclic and bicyclic groups containing from five to twelve ring members, and more usually from five to ten ring members.
- the heteroaryl group can be, for example, a 5- or 6-membered monocyclic ring or a 9- or 10-membered bicyclic ring, for example a bicyclic structure formed from fused five and six membered rings or two fused six membered rings.
- Each ring may contain up to about four heteroatoms typically selected from nitrogen, sulfur and oxygen.
- the heteroaryl ring will contain up to 3 heteroatoms, more usually up to 2, for example a single heteroatom.
- heteroaryl(m-nC)alkyl refers to group -(Ch V n -heteroaryl, wherein heteroaryl has any of definitions outlined above.
- heteroaryloxy refers to -O-heteroaryl, wherein heteroaryl has any of the definitions discussed herein.
- halogen or“halo” as used herein refers to F, Cl, Br or I. In particular, halogen may Cl.
- substituted as used herein in reference to a moiety means that one or more, especially up to 5, more especially 1 , 2 or 3, of the hydrogen atoms in said moiety are replaced independently of each other by the corresponding number of the described substituents.
- optionally substituted as used herein means substituted or unsubstituted.
- R 1 is selected from the group consisting of (1-4C)alkyl, (2-4C)alkenyl, (1- 4C)alkoxy, aryloxy, aryl, aryl(1-2C)alkyl, heteroaryloxy, heteroaryl and heteroaryl(1- 2C)alkyl, wherein said (1-4C)alkyl, (2-4C)alkenyl, (1-4C)alkoxy, aryloxy, aryl, aryl(1- 2C)alkyl, heteroaryloxy, heteroaryl and heteroaryl(1-2C)alkyl are optionally substituted with one or more groups selected from the group consisting of halo, amino, hydroxy, (1- 4C)alkyl, (2-4C)alkenyl and (1-4C)alkoxy;
- X is selected from zirconium or hafnium
- each Y is independently selected from the group consisting of halo, (1-4C)alkyl, (1-4C)alkoxy and aryloxy, wherein said (1-4C)alkyl, (1-4C)alkoxy and aryloxy are optionally substituted with one or more groups selected from the group consisting of halo, amino, hydroxy and (1-4C)alkyl.
- the compounds of formula I are effective initiators/catalysts in the polymerisation of cyclic esters, such as lactides and lactones.
- boron tends to form electron deficient configurations in which a trivalent boron atom has an incomplete outer shell of electrons.
- trivalent boron atoms typically have an affinity for an additional 2 electrons (e.g. an atom having a lone pair).
- the present invention encompasses compounds of formula I wherein the boron atom is optionally coordinated to a lone pair-donating species.
- a lone pair-donating species is a solvent (e.g. an oxygen-containing solvent) in which the compound may have been synthesised, such as diethyl ether or tetrahydrofuran.
- the compounds of the invention may be present in one or more isomeric forms.
- the compounds of the invention may be present as meso or rac isomers, and the invention includes both such isomeric forms.
- a person skilled in the art will appreciate that a mixture of isomers of the compound of the invention may be used for catalysis applications, or the isomers may be separated and used individually (using techniques well known in the art, such as, for example, fractional crystallisation).
- R 1 is selected from the group consisting of (1-4C)alkyl, (1-4C)alkoxy, aryloxy, aryl, aryl(1-2C)alkyl, heteroaryl and heteroaryl(1-2C)alkyl, wherein said (1-4C)alkyl, (1- 4C)alkoxy, aryloxy, aryl, aryl(1-2C)alkyl, heteroaryl and heteroaryl(1-2C)alkyl are optionally substituted with one or more groups selected from the group consisting of halo, amino, hydroxy, (1-4C)alkyl and (1-4C)alkoxy.
- R 1 is selected from the group consisting of aryloxy, aryl, aryl(1-2C)alkyl, heteroaryl and heteroaryl(1-2C)alkyl, wherein said aryloxy, aryl, aryl(1-2C)alkyl, heteroaryl and heteroaryl(1-2C)alkyl are optionally substituted with one or more groups selected from the group consisting of halo, (1-4C)alkyl and (1-4C)alkoxy.
- R 1 is selected from the group consisting of phenoxy, phenyl, benzyl, 6- membered heteroaryl and 6-membered heteroaryl(1-2C)alkyl, wherein said phenoxy, phenyl, benzyl, 6-membered heteroaryl and 6-membered heteroaryl(1-2C)alkyl are optionally substituted with one or more groups selected from the group consisting of (1-4C)alkyl and (1- 4C)alkoxy.
- R 1 is selected from the group consisting of phenoxy and phenyl, wherein said phenoxy and phenyl are optionally substituted with one or more groups selected from the group consisting of (1-4C)alkyl and (1-4C)alkoxy.
- R 1 is phenyl optionally substituted with one or more (e.g. 1 , 2 or 3) groups selected from the group consisting of (1-4C)alkyl.
- R 1 is phenyl
- X is Hf.
- X is Zr.
- the Y groups may be identical or different.
- both Y groups are identical.
- each Y is independently selected from the group consisting of halo, (1-4C)alkyl, (1-4C)alkoxy and phenoxy, wherein said (1-4C)alkyl, (1-4C)alkoxy and phenoxy are optionally substituted with one or more groups selected from the group consisting of halo and (1-4C)alkyl.
- each Y is independently selected from the group consisting of halo and (1- 4C)alkyl, wherein said (1-4C)alkyl is optionally substituted with one or more groups selected from the group consisting of halo and (1-2C)alkyl.
- each Y is independently selected from the group consisting of halo and (1-2C)alkyl.
- each Y is independently selected from the group consisting of Cl and methyl.
- both Y groups are Cl.
- the compound having a structure according to formula I has a structure according to formula la shown below:
- each Y independently has any of those definitions appearing hereinbefore;
- Ph denotes phenyl
- Q is selected from the group consisting of absent (in which case B is bonded directly to Ph), O and (Chhj n , wherein n is 1 or 2.
- the compound has a structure according to formula la, wherein Q is absent.
- the compound has a structure according to formula la, wherein Q is -(CH 2 )-.
- the compound has a structure according to formula la, wherein Q is O.
- the compound having a structure according to formula I has a structure according to formula lb shown below:
- each Y independently has any of those definitions appearing hereinbefore; Ph denotes phenyl; and
- Q is selected from the group consisting of absent (in which case B is bonded directly to Ph), O and (CH 2 ) n , wherein n is 1 or 2.
- the compound has a structure according to formula lb, wherein Q is absent. [0051] In an embodiment, the compound has a structure according to formula lb, wherein Q is -(CH 2 )-.
- the compound has a structure according to formula lb, wherein Q is O.
- the compound having a structure according to formula I has a structure according to formula lc shown below:
- Ph denotes phenyl
- Q is selected from the group consisting of absent (in which case B is bonded directly to Ph), O and (CH 2 ) n , wherein n is 1 or 2.
- the compound has a structure according to formula lc, wherein Q is absent.
- the compound has a structure according to formula lc, wherein Q is -(CH 2 )-.
- the compound has a structure according to formula lc, wherein Q is O.
- the compound has the following structure: wherein Ph notes phenyl.
- the compounds of the invention may be formed by any suitable process known in the art. Particular examples of processes for the preparation of compounds of the invention are set out in the accompanying examples.
- M is Li in step (i) of the process defined above.
- the compound of formula B may be provided as a solvate, such as X(Y’) .THF P , where p is an integer (e.g. 2).
- Any suitable solvent may be used for step (i) of the process defined above.
- a particularly suitable solvent is toluene, benzene or THF.
- step (ii) If a compound of formula I in which Y is other than halo is required, then the compound of formula I’ above may be further reacted in the manner defined in step (ii) to provide a compound of formula I”.
- Any suitable solvent may be used for step (ii) of the process defined above.
- a suitable solvent may be, for example, diethyl ether, toluene, THF, dichloromethane, chloroform, hexane DMF, benzene etc.
- suitable reaction conditions e.g. temperature, pressures, reaction times, agitation etc.
- Compounds of formula A may generally be prepared by:
- step (ii) reacting, in a suitable solvent (such as diethyl ether), the product of step (i) above with a basic organometallic compound (such as n-BuLi).
- a suitable solvent such as diethyl ether
- a basic organometallic compound such as n-BuLi
- reaction conditions e.g. temperature, pressures, reaction times, agitation etc.
- a process for the ring opening polymerisation (ROP) of a cyclic ester comprising the step of contacting a compound according to the first aspect with one or more cyclic esters.
- the compounds of formula I are effective initiators/catalysts in the polymerisation of cyclic esters, such as lactides and lactones.
- the cyclic ester is selected from the group consisting of lactides and lactones.
- the cyclic ester is a lactide having any one of the following structures:
- the compound of formula I is used in combination with a hydroxylated activator compound.
- the hydroxylated activator compound is selected from the group consisting of tert-butanol, benzyl alcohol and iso-propanol. More suitably, the hydroxylated activator compound is benzyl alcohol.
- the compound of formula I may be contacted with the one or more cyclic esters in any suitable solvent.
- the solvent is deuterated benzene or deuterated chloroform.
- the compound of formula I may be contacted with the one or more cyclic esters at any suitable temperature.
- the compound of formula I is contacted with the one or more cyclic esters at 50 - 100°C (e.g. 70 - 90°C).
- Fig. 1 shows the 1 H NMR spectrum of ( Ph BBI * )H2 in O Q O Q.
- Fig. 2 shows the solid state structure of ( Ph BBI*)H 2 . Thermal ellipsoids are drawn at 50% probability and hydrogen atoms have been omitted for clarity.
- Fig. 3 shows the 1 H NMR spectrum of ( Ph BBI * )Li 2 .
- Fig. 4 shows the 1 H NMR spectrum of rac-( Ph BBI*)ZrCI 2 in C 6 D 6 .
- Fig. 5 shows the solid state structure of rac-( Ph BBI*)ZrCl2 obtained by recrystallisation from Et 2 0. Thermal ellipsoids are drawn at 50% probability and hydrogen atoms have been omitted for clarity.
- Fig. 6 shows the polymerisation of L- Lactide using rac- BBI*ZrCI 2 in chloroform-di (black square), benzene-cfe (black circle) and in chloroform-cfi with 3 equivalent of benzyl alcohol (black triangle).
- Figure 6 shows that the polymerisation of /.-lactide using rac- BBIVrC is faster in benzene-d 6 than in chloroform-di . Flowever, the polymerisation reaction is seen to proceed even faster when 3 equivalent of benzyl alcohol were added, suggesting the use of an activated monomer mechanism.
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Abstract
Compounds suitable for use in the polymerisation of cyclic esters, such as lactides and lactones, are described. Also described is a process for polymerising cyclic esters using the described compounds.
Description
COMPOUNDS SUITABLE FOR USE IN THE POLYMERISATION OF CYCLIC ESTERS
INTRODUCTION
[0001] The present invention relates to compounds that are suitable for use in the polymerisation of cyclic esters, such as lactides and lactones. More specifically, the present invention relates to ansa-metallocene compounds that are suitable for this use. The invention also relates to a process for the ring opening polymerisation (ROP) of cyclic esters, such as lactides and lactones.
BACKGROUND OF THE INVENTION
[0002] Poly(lactic acids) (PLAs) have been studied intensively over the past few decades due to the promise they have shown as potential alternatives to petroleum-based polymers for uses as plastics, fibres and coatings. Moreover, since PLAs are both biodegradable and biocompatible, they are of equal value to the field of medicine, wherein their versatile physical properties make them suitable for in vivo applications (e.g. as media for controlled drug delivery devices).
[0003] Lactic acid forms PLA upon polycondensation. However, the fact that this reaction is in equilibrium, and the difficulties in completely removing water, makes it difficult to obtain PLAs of high molecular weight. With this in mind, ring opening polymerisation (ROP) of lactides is the most efficient route to PLAs.
[0004] Metal complexes useful for initiating ring opening polymerisation of lactides are known.
[0005] Wenshan Ren et al, Inorganic Chemistry Communications, 30, (2013), 26-28 report that benzyl thorium metallocenes [q5-1 ,3-(Me3C)2C5H3]2 Th(CH2Ph)2 (1 ) and [n5-1 ,2,4-(Me3C)3CsH2]2 Th(CH2Ph)2 (2) can initiate the ring opening polymerisation of racemic-lactide (rac-LA) under mild conditions. Complete conversion of 500 equiv of lactide occurs within 5h at 40°C in dichloromethane at [rac-LA]=1.0 mol L \ and the molecular weight distribution is very narrow (ca.1.15) over the entire monomer-to-initiator range, indicating a single-site catalyst system.
[0006] Yalan Ning et a/, Organometallics 2008, 27, 5632-5640 report four neutral zirconocene bis(ester enolate) and non-zirconocene bis(alkoxy) complexes employed for ring-opening polymerisations and chain transfer polymerisations of L-lactide ( -LA) and e-caprolactone (e- CL).
[0007] WO2017/060691 describes asymmetrical ansa-metallocene complexes containing an indenyl ligands and a cyclopentadienyl ligand linked to one another via a dimethylsilyene bridging group.
[0008] In spite of the above, due to the high value that industry places on materials such as PLAs, there remains a need for compounds effective in the polymerisation of cyclic esters, such as lactides and lactones.
[0009] The present invention was devised with the foregoing in mind.
SUMMARY OF THE INVENTION
[0010] According to a first aspect of the present invention there is provided a compound having a structure according to formula I defined herein.
[0011] According to a second aspect of the present invention there is provided a process for the ring opening polymerisation (ROP) of a cyclic ester, the process comprising the step of contacting a compound according to the first aspect with one or more cyclic esters.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0012] The term "(m-nC)" or "(m-nC) group" used alone or as a prefix, refers to any group having m to n carbon atoms.
[0013] The term “alkyl” as used herein refers to straight or branched chain alkyl moieties, typically having 1 , 2, 3, 4, 5 or 6 carbon atoms. This term includes reference to groups such as methyl, ethyl, propyl (n-propyl or isopropyl), butyl (n-butyl, sec-butyl or tert-butyl), pentyl, hexyl and the like. In particular, an alkyl may have 1 , 2, 3 or 4 carbon atoms.
[0014] The term“alkenyl” as used herein refers to straight or branched chain alkenyl moieties, typically having 1 , 2, 3, 4, 5 or 6 carbon atoms. The term includes reference to alkenyl moieties containing 1 , 2 or 3 carbon-carbon double bonds (C=C). This term includes reference to groups such as ethenyl (vinyl), propenyl (allyl), butenyl, pentenyl and hexenyl, as well as both the cis and trans isomers thereof.
[0015] The term“alkynyl” as used herein refers to straight or branched chain alkynyl moieties, typically having 1 , 2, 3, 4, 5 or 6 carbon atoms. The term includes reference to alkynyl moieties containing 1 , 2 or 3 carbon-carbon triple bonds (CºC). This term includes reference to groups such as ethynyl, propynyl, butynyl, pentynyl and hexynyl.
[0016] The term“alkoxy” as used herein refers to -O-alkyl, wherein alkyl is straight or branched chain and comprises 1 , 2, 3, 4, 5 or 6 carbon atoms. In one class of embodiments, alkoxy has 1 , 2, 3 or 4 carbon atoms. This term includes reference to groups such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, tert-butoxy, pentoxy, hexoxy and the like.
[0017] The term "aryl" or“aromatic” as used herein means an aromatic ring system comprising 6, 7, 8, 9 or 10 ring carbon atoms. Aryl is often phenyl but may be a polycyclic ring system, having two or more rings, at least one of which is aromatic. This term includes reference to groups such as phenyl, naphthyl and the like. A particularly suitable aryl group is phenyl.
[0018] The term “aryl(m-nC)alky refers to group -(CH2)m-n-aryl, wherein aryl has any of definitions outlined above. A particular aryl(m-nC)alkyl group is benzyl.
[0019] The term “aryloxy” as used herein refers to -O-aryl, wherein aryl has any of the definitions discussed herein.
[0020] The term“heteroaryl” or“heteroaromatic” means an aromatic mono-, bi-, or polycyclic ring incorporating one or more (for example 1-4, particularly 1 , 2 or 3) heteroatoms selected from nitrogen, oxygen or sulfur. Examples of heteroaryl groups are monocyclic and bicyclic groups containing from five to twelve ring members, and more usually from five to ten ring members. The heteroaryl group can be, for example, a 5- or 6-membered monocyclic ring or a 9- or 10-membered bicyclic ring, for example a bicyclic structure formed from fused five and six membered rings or two fused six membered rings. Each ring may contain up to about four heteroatoms typically selected from nitrogen, sulfur and oxygen. Typically the heteroaryl ring will contain up to 3 heteroatoms, more usually up to 2, for example a single heteroatom.
[0021] The term “heteroaryl(m-nC)alkyl” refers to group -(Ch Vn-heteroaryl, wherein heteroaryl has any of definitions outlined above.
[0022] The term“heteroaryloxy” as used herein refers to -O-heteroaryl, wherein heteroaryl has any of the definitions discussed herein.
[0023] The term "halogen" or“halo” as used herein refers to F, Cl, Br or I. In particular, halogen may Cl.
[0024] The term“substituted” as used herein in reference to a moiety means that one or more, especially up to 5, more especially 1 , 2 or 3, of the hydrogen atoms in said moiety are replaced independently of each other by the corresponding number of the described substituents. The term“optionally substituted” as used herein means substituted or unsubstituted.
[0025] It will, of course, be understood that substituents are only at positions where they are chemically possible, the person skilled in the art being able to decide (either experimentally or theoretically) without inappropriate effort whether a particular substitution is possible.
Compounds of the invention
[0026] According to a first aspect of the present invention there is provided a compound having a structure according to formula I shown below:
R1 is selected from the group consisting of (1-4C)alkyl, (2-4C)alkenyl, (1- 4C)alkoxy, aryloxy, aryl, aryl(1-2C)alkyl, heteroaryloxy, heteroaryl and heteroaryl(1- 2C)alkyl, wherein said (1-4C)alkyl, (2-4C)alkenyl, (1-4C)alkoxy, aryloxy, aryl, aryl(1- 2C)alkyl, heteroaryloxy, heteroaryl and heteroaryl(1-2C)alkyl are optionally substituted with one or more groups selected from the group consisting of halo, amino, hydroxy, (1- 4C)alkyl, (2-4C)alkenyl and (1-4C)alkoxy;
X is selected from zirconium or hafnium; and
each Y is independently selected from the group consisting of halo, (1-4C)alkyl, (1-4C)alkoxy and aryloxy, wherein said (1-4C)alkyl, (1-4C)alkoxy and aryloxy are optionally substituted with one or more groups selected from the group consisting of halo, amino, hydroxy and (1-4C)alkyl.
[0027] The compounds of formula I are effective initiators/catalysts in the polymerisation of cyclic esters, such as lactides and lactones.
[0028] It will be understood by one of ordinary skill in the art that boron tends to form electron deficient configurations in which a trivalent boron atom has an incomplete outer shell of electrons. As a consequence, trivalent boron atoms typically have an affinity for an additional 2 electrons (e.g. an atom having a lone pair). It will therefore be understood that the present invention encompasses compounds of formula I wherein the boron atom is optionally coordinated to a lone pair-donating species. A particular example of such a lone pair-donating
species is a solvent (e.g. an oxygen-containing solvent) in which the compound may have been synthesised, such as diethyl ether or tetrahydrofuran.
[0029] The compounds of the invention may be present in one or more isomeric forms. In particular, the compounds of the invention may be present as meso or rac isomers, and the invention includes both such isomeric forms. A person skilled in the art will appreciate that a mixture of isomers of the compound of the invention may be used for catalysis applications, or the isomers may be separated and used individually (using techniques well known in the art, such as, for example, fractional crystallisation).
[0030] It will be appreciated that the structural formula I presented above is intended to show the substituent groups in a clear manner. More representative illustrations of the spatial arrangement of the groups are shown below:
[0031] In an embodiment, R1 is selected from the group consisting of (1-4C)alkyl, (1-4C)alkoxy, aryloxy, aryl, aryl(1-2C)alkyl, heteroaryl and heteroaryl(1-2C)alkyl, wherein said (1-4C)alkyl, (1- 4C)alkoxy, aryloxy, aryl, aryl(1-2C)alkyl, heteroaryl and heteroaryl(1-2C)alkyl are optionally substituted with one or more groups selected from the group consisting of halo, amino, hydroxy, (1-4C)alkyl and (1-4C)alkoxy.
[0032] Suitably, R1 is selected from the group consisting of aryloxy, aryl, aryl(1-2C)alkyl, heteroaryl and heteroaryl(1-2C)alkyl, wherein said aryloxy, aryl, aryl(1-2C)alkyl, heteroaryl and heteroaryl(1-2C)alkyl are optionally substituted with one or more groups selected from the group consisting of halo, (1-4C)alkyl and (1-4C)alkoxy.
[0033] More suitably, R1 is selected from the group consisting of phenoxy, phenyl, benzyl, 6- membered heteroaryl and 6-membered heteroaryl(1-2C)alkyl, wherein said phenoxy, phenyl, benzyl, 6-membered heteroaryl and 6-membered heteroaryl(1-2C)alkyl are optionally substituted with one or more groups selected from the group consisting of (1-4C)alkyl and (1- 4C)alkoxy.
[0034] Even more suitably, R1 is selected from the group consisting of phenoxy and phenyl, wherein said phenoxy and phenyl are optionally substituted with one or more groups selected from the group consisting of (1-4C)alkyl and (1-4C)alkoxy.
[0035] Yet more suitably, R1 is phenyl optionally substituted with one or more (e.g. 1 , 2 or 3) groups selected from the group consisting of (1-4C)alkyl.
[0036] Most suitably, R1 is phenyl.
[0037] In an embodiment, X is Hf.
[0038] Most suitably, X is Zr.
[0039] The Y groups may be identical or different. Suitably, both Y groups are identical.
[0040] In an embodiment, each Y is independently selected from the group consisting of halo, (1-4C)alkyl, (1-4C)alkoxy and phenoxy, wherein said (1-4C)alkyl, (1-4C)alkoxy and phenoxy are optionally substituted with one or more groups selected from the group consisting of halo and (1-4C)alkyl.
[0041] Suitably, each Y is independently selected from the group consisting of halo and (1- 4C)alkyl, wherein said (1-4C)alkyl is optionally substituted with one or more groups selected from the group consisting of halo and (1-2C)alkyl.
[0042] More suitably, each Y is independently selected from the group consisting of halo and (1-2C)alkyl.
[0043] Even more suitably, each Y is independently selected from the group consisting of Cl and methyl.
[0044] Most suitably, both Y groups are Cl.
[0045] In an embodiment, the compound having a structure according to formula I has a structure according to formula la shown below:
each Y independently has any of those definitions appearing hereinbefore;
X has any of those definitions appearing hereinbefore;
Ph denotes phenyl; and
Q is selected from the group consisting of absent (in which case B is bonded directly to Ph), O and (Chhjn, wherein n is 1 or 2.
[0046] In an embodiment, the compound has a structure according to formula la, wherein Q is absent.
[0047] In an embodiment, the compound has a structure according to formula la, wherein Q is -(CH2)-.
[0048] In an embodiment, the compound has a structure according to formula la, wherein Q is O.
[0049] In an embodiment, the compound having a structure according to formula I has a structure according to formula lb shown below:
each Y independently has any of those definitions appearing hereinbefore; Ph denotes phenyl; and
Q is selected from the group consisting of absent (in which case B is bonded directly to Ph), O and (CH2)n, wherein n is 1 or 2.
[0050] In an embodiment, the compound has a structure according to formula lb, wherein Q is absent.
[0051] In an embodiment, the compound has a structure according to formula lb, wherein Q is -(CH2)-.
[0052] In an embodiment, the compound has a structure according to formula lb, wherein Q is O.
[0053] In an embodiment, the compound having a structure according to formula I has a structure according to formula lc shown below:
X has any of those definitions appearing hereinbefore;
Ph denotes phenyl; and
Q is selected from the group consisting of absent (in which case B is bonded directly to Ph), O and (CH2)n, wherein n is 1 or 2.
[0054] In an embodiment, the compound has a structure according to formula lc, wherein Q is absent.
[0055] In an embodiment, the compound has a structure according to formula lc, wherein Q is -(CH2)-.
[0056] In an embodiment, the compound has a structure according to formula lc, wherein Q is O.
[0057] In an embodiment, the compound has the following structure:
wherein Ph notes phenyl.
Synthesis of compounds
[0058] The compounds of the invention may be formed by any suitable process known in the art. Particular examples of processes for the preparation of compounds of the invention are set out in the accompanying examples.
[0059] Generally, the processes of preparing a compound of the invention as defined herein comprises:
(i) reacting a compound of formula A:
A
(wherein Ri is as defined hereinbefore and M is Li, Na or K)
with a compound of the formula B:
X(Y')4
B
(wherein X is as defined hereinbefore and Y’ is halo (particularly chloro or bromo)) in the presence of a suitable solvent to form a compound of formula I’:
I’
and optionally thereafter:
(ii) reacting the compound of formula G above with MY” (wherein M is as defined above and Y” is a group Y as defined herein other than halo), in the presence of a suitable solvent to form the compound of the formula I” shown below
[0060] Suitably, M is Li in step (i) of the process defined above.
[0061] The compound of formula B may be provided as a solvate, such as X(Y’) .THFP, where p is an integer (e.g. 2).
[0062] Any suitable solvent may be used for step (i) of the process defined above. A particularly suitable solvent is toluene, benzene or THF.
[0063] If a compound of formula I in which Y is other than halo is required, then the compound of formula I’ above may be further reacted in the manner defined in step (ii) to provide a compound of formula I”.
[0064] Any suitable solvent may be used for step (ii) of the process defined above. A suitable solvent may be, for example, diethyl ether, toluene, THF, dichloromethane, chloroform, hexane DMF, benzene etc.
A person of skill in the art will be able to select suitable reaction conditions (e.g. temperature, pressures, reaction times, agitation etc.) for such a synthesis.
[0065] Compounds of formula A may generally be prepared by:
(i) reacting, in a suitable solvent (such as diethyl ether), two equivalents of a compound having formula C shown below
(wherein M is Li, Na or K) with one equivalent of a compound having formula D shown below:
R
LG \ LG
D
(wherein R1 has any of those definitions appearing hereinbefore; and each LG is independently a leaving group, e.g. Cl); and
(ii) reacting, in a suitable solvent (such as diethyl ether), the product of step (i) above with a basic organometallic compound (such as n-BuLi).
[0066] Compounds of formula D can be readily synthesised by techniques well known in the art.
[0067] A person of skill in the art will be able to select suitable reaction conditions (e.g. temperature, pressures, reaction times, agitation etc.) for such a synthesis.
Polymerisation of cyclic esters
[0068] According to a second aspect of the present invention there is provided a process for the ring opening polymerisation (ROP) of a cyclic ester, the process comprising the step of contacting a compound according to the first aspect with one or more cyclic esters.
[0069] The compounds of formula I are effective initiators/catalysts in the polymerisation of cyclic esters, such as lactides and lactones.
[0070] In an embodiment, the cyclic ester is selected from the group consisting of lactides and lactones.
[0071] In an embodiment, the cyclic ester is a lactide having any one of the following structures:
[0072] In an embodiment, the compound of formula I is used in combination with a hydroxylated activator compound. Suitably, the hydroxylated activator compound is selected from the group consisting of tert-butanol, benzyl alcohol and iso-propanol. More suitably, the hydroxylated activator compound is benzyl alcohol.
[0073] The compound of formula I may be contacted with the one or more cyclic esters in any suitable solvent. In an embodiment, the solvent is deuterated benzene or deuterated chloroform.
[0074] The compound of formula I may be contacted with the one or more cyclic esters at any suitable temperature. In an embodiment, the compound of formula I is contacted with the one or more cyclic esters at 50 - 100°C (e.g. 70 - 90°C).
EXAMPLES
[0075] One or more examples of the invention will now be described, for the purpose of illustration only, with reference to the accompanying figures, in which:
Fig. 1 shows the 1 H NMR spectrum of (PhBBI*)H2 in OQOQ.
Fig. 2 shows the solid state structure of (PhBBI*)H2. Thermal ellipsoids are drawn at 50% probability and hydrogen atoms have been omitted for clarity.
Fig. 3 shows the 1 H NMR spectrum of (PhBBI*)Li2.
Fig. 4 shows the 1 H NMR spectrum of rac-(Ph BBI*)ZrCI2 in C6D6.
Fig. 5 shows the solid state structure of rac-(Ph BBI*)ZrCl2 obtained by recrystallisation from Et20. Thermal ellipsoids are drawn at 50% probability and hydrogen atoms have been omitted for clarity.
Fig. 6 shows the polymerisation of L- Lactide using rac- BBI*ZrCI2 in chloroform-di (black square), benzene-cfe (black circle) and in chloroform-cfi with 3 equivalent of benzyl alcohol (black triangle). Polymerisation conditions: 80 °C, [LA]0/[Zr]]o = 50, [LA]0 = 0.5 M.
Example 1 - Preparation of (PhBBI*)ZrCI2
Synthesis of (PhBBI*lH?
[0076] Having regard to Scheme 1 below, to a solution of lnd#Li (2 g, 9.70 mmol) in Et20 (40 mL) at 0 °C, was added dropwise a solution of PhBCI2 (0.6 mL, 4.79 mmol) in Et20 (20 mL) at 0 °C. The suspension turned yellow and was allowed to warm to room temperature and stir for 18 h. The reaction was filtered and the residual solids were washed with Et20 (3 x 20 mL). The combined filtrates were dried in vacuo and the crude solids washed with pentane at 0 °C (3 x 20 mL). The bulk yellow solid was redissolved in Et20 and stored at -35 °C to afford yellow crystals suitable for X-ray diffraction analysis. A second crop of (PhBBI*)H2 was obtained by storing the pentane washings at -35 °C. Compound (PhBBI*)H2 was isolated in a total yield of 28% (640 mg, 1.32 mmol).
1H NMR (400 MHz, C6D6, 298 K): 5 8.10 (2H, m, o-PhH), 7.35 (3H, m, m, p-PhH), 4.18 (2H, s, IndH), 2.35 (6H, s, IndMe), 2.19 (6H, s, IndMe), 2.05 (6H, s, IndMe), 1.98 (6H, s, IndMe) and 1.67 (12H, s, IndMe). 13C{1 H} NMR (125 MHz, C6D6, 298 K): d 143.44 (Ind), 136.96 (Ind), 136.47 (Ind), 133.53 (o-Ph), 132.34 (Ind), 131.73 (p-Ph), 129.08 (Ind), 128.72 (m-Ph), 127.62 (Ind), 125.37 (Ind), 46.81 (IndH), 18.32 (IndMe), 16.51 (IndMe), 16.19 (IndMe), 16.16 (IndMe), 15.57 (IndMe) and 15.36 (IndMe). An additional Ind 13C resonance was expected, but was not observed, presumably obscured by the solvent resonance. Elemental analysis (%): Expected: C 88.87, H 8.91 ; found: C 88.76, H 8.60.
Scheme 1. Preparation of (PhBBI*)H2 from lnd#Li
[0077] The 1 H NMR spectrum of (PhBBI*)H2 in CsD6 (Figure 1) shows five singlets between 1.67 and 2.35 ppm (with one signal twice the intensity of the others) for the methyl groups. A resonance was observed for the allylic indenyl protons at 4.18 ppm, and two multiplets at 7.35 and 8.10 ppm correspond to the meta-lpara- and o/f/70-protons of the phenyl rings respectively.
[0078] Yellow crystals suitable for single crystal X-ray diffraction were grown from Et20 at -35 °C in the triclinic space group P-1. The molecular structure is shown in Figure 2.
Synthesis of (PhBBI*M_i?
[0079] Having regard to Scheme 2 shown below, to a solution of (PhBBI*)H2 (500 mg, 1.03 mmol) in Et20 (20 mL) at 0 °C was added "BuLi (1.6 ml_, 1.6 M in hexanes, 2.56 mmol) dropwise, and the reaction left to warm to room temperature and stir for 2 h. A colour change from yellow to red was observed. The solvent was removed in vacuo and the residues were washed with pentane at 0 °C (2 x 20 mL), to afford an orange powder in 68% yield (350 mg, 0.70 mmol).
Ή NMR (400 MHz, C6D5N, 298 K): <5 8.18 (2H, m, o-PhH), 7.14 (3H, m, m, p-PhH), 3.05 (6H, s, IndMe), 2.98 (6H, s, IndMe), 2.70 (6H, s, IndMe), 2.58 (6H, s, IndMe), 1 .41 (6H, s, IndMe) and 1.27 (6H, s, IndMe). 7Li NMR (156 MHz, C6D5N, 298 K): 6 -0.74.
Scheme 2. Preparation of (PhBBI*)Li2from (PhBBI*)H2
[0080] The 1 H NMR spectrum in C5D5N of (PhBBI*)Li2 (Figure 3) showed 6 singlets between 1.27 and 3.05 ppm corresponding to the indenyl methyl groups, a multiplet at 7.14 ppm assigned to the meta- and para- phenyl protons, and a multiplet at 8.18 ppm assigned to the ortho- phenyl protons. The chemical shift for the indenyl methyl and phenyl protons have not significantly changed from (PhBBI*)H2, however the resonance at 4.18 ppm for the allylic indenyl proton is no longer observed in (PhBBI*)Li2, indicating total deprotonation by "BuLi.
Synthesis of (PhBBnZrCI?
[0081] Having regard to Scheme 3 below, ZrCU (164 mg, 0.70 mmol) was added to (PhBBI*)Li2 (350 mg, 0.70 mmol), followed by toluene (30 mL) and Et20 (1 ml_). The reaction was allowed to stir for 18 h and a colour change from pale to dark red was observed. The reaction was filtered, and the filtrate was dried under vacuum, yielding a red solid. This solid was washed with pentane (3 x 20 mL), then dissolved in a minimum volume of Et20 and stored at -35 °C to obtain red crystals of isomerically pure rac-(Ph BBI*)ZrCI2, which were suitable for X-ray diffraction analysis, in a crystalline yield of 4% (20 mg, 0.030 mmol).
[0082] When ZrCU (164 mg, 0.70 mmol) was added to (PhBBI*)Li2 (350 mg, 0.70 mmol), followed by benzene (30 mL) and the reaction was allowed to stir for 18 h, a colour change from pale to dark red was again observed. The reaction was dried, and washed with hexane (3 x 60 mL). The reaction mixture was filtered and stored at -35 °C to obtain red crystals. 1 H NMR spectroscopy showed a 2:1 rac- to meso- ratio of isomers.
Ή NMR (rac-(Ph BBI*)ZrCI2) (400 MHz, C6D6, 298 K): d 8.50 (2H, m, o-PhH), 7.38 (3H, m, m-, p-PhH), 2.53 (6H, s, IndMe), 2.50 (6H, s, IndMe), 2.20 (6H, s, IndMe), 2.03 (6H, s, IndMe), 1.91 (6H, s, IndMe) and 1.79 (6H, s, IndMe). 1 H NMR (meso-(PhBBI*)ZrCI2) (400 MHz, CSD6, 298 K): d 8.55 (2H, m, o-PhH), 7.35 (3H, m, m -, p-PhH), 2.53 (6H, s, IndMe), 2.46 (6H, s, IndMe), 2.29 (6H, s, IndMe), 2.00 (6H, s, IndMe) and 1.87 (6H, s, IndMe) and 1 .65 (6H, s,
IndMe). 13C{1H} NMR (rac-2.3) (125 MHz, C6DS, 298 K): d 139.25 (o-Ph), 135.50 (m- Ph), 133.34 (Ind), 133.28 (Ind), 130.55 (Ind), 130.53 (Ind), 129.16 (Ind), 128.76 (p-Ph), 126.95 (Ind), 125.78 (Ind), 23.43 (IndMe), 17.26 (IndMe), 16.62 (IndMe), 16.27 (IndMe), 15.78 (IndMe) and 15.37 (IndMe). An additional two Ind 13C resonances were expected, but were not observed, presumably obscured by the solvent resonance. 11B{1H} NMR (rac-(Ph BBI*)ZrCl2) (160 MHz, CeDe, 298 K): d 73.5. MS (El) (rac-(PhBBI*)ZrCI2): Predicted: m/z 643.1781. Observed: m/z 643.1756. Elemental analysis (%) (rac-(PhBBI*)ZrCI2): Expected: C 66.87, H 6.39; found: C 66.85, H 6.47
Scheme 3. Preparation of (PhBBI*)ZrCI2 from (PhBBI*)Li2
[0083] The 1H NMR spectrum of rac-(PhBBI*)ZrCI2 in C6D6, (Figure 4) shows 6 singlets of equal intensity between 1.79 and 2.53 ppm corresponding to the six methyl groups. Two multiplets observed at 7.38 and 8.50 ppm were attributed to the meta /para- and orfPo-phenyl protons respectively.
[0084] Recrystallisation from Et20 at -35 °C afforded single crystals of rac-(Ph BBI*)ZrCI2 suitable for X-ray diffraction, in the monoclinic space group P2i/c. The molecular structure is shown in Figure 5. In this synthesis, isomerically pure crystals were obtained in a 4% crystalline yield. Synthesis of rac-(PhBBI*)ZrCI2 from (PhBBI*)Li2 in the absence of Et20 with recrystallisation from hexane afforded a mixture of rac- and meso- products in a 2:1 ratio.
[0085] It was expected that the Et20 would act as a donor group to the boron atom. However there was no evidence of any tetra coordinated boron atoms in (PflBBI*)ZrCI2, either in the crystal structure or in the 1H NMR spectrum.
Example 2 - Lactide polymerisation
[0086] 40 mg of L-lactide and 3.6 mg of rac- BBFZrCh (Example 1) were introduced into an NMR tube and dissolve into 0.56 mL of the chosen deuterated solvent. Where required, 1.2 mg of benzyl alcohol was added. The polymerisation kinetics were followed by 1H NMR spectroscopy. The results are presented in Figure 6.
[0087] Figure 6 shows that the polymerisation of /.-lactide using rac- BBIVrC is faster in benzene-d6 than in chloroform-di . Flowever, the polymerisation reaction is seen to proceed even faster when 3 equivalent of benzyl alcohol were added, suggesting the use of an activated monomer mechanism.
[0088] While specific embodiments of the invention have been described herein for the purpose of reference and illustration, various modifications will be apparent to a person skilled in the art without departing from the scope of the invention as defined by the appended claims.
Claims
1. A compound suitable for use in the polymerisation of cyclic esters, the compound
having a structure according to formula I shown below:
R1 is selected from the group consisting of (1-4C)alkyl, (2-4C)alkenyl, (1- 4C)alkoxy, aryloxy, aryl, aryl(1-2C)alkyl, heteroaryloxy, heteroaryl and heteroaryl(1- 2C)alkyl, wherein said (1-4C)alkyl, (2-4C)alkenyl, (1-4C)alkoxy, aryloxy, aryl, aryl(1- 2C)alkyl, heteroaryloxy, heteroaryl and heteroaryl(1-2C)alkyl are optionally substituted with one or more groups selected from the group consisting of halo, amino, hydroxy, (1- 4C)alkyl, (2-4C)alkenyl and (1-4C)alkoxy;
X is selected from zirconium or hafnium; and
each Y is independently selected from the group consisting of halo, (1-4C)alkyl, (1-4C)alkoxy and aryloxy, wherein said (1-4C)alkyl, (1-4C)alkoxy and aryloxy are optionally substituted with one or more groups selected from the group consisting of halo, amino, hydroxy and (1-4C)alkyl.
2. The compound of claim 1 , wherein R1 is selected from the group consisting of (1- 4C)alkyl, (1-4C)alkoxy, aryloxy, aryl, aryl(1-2C)alkyl, heteroaryl and heteroaryl(1- 2C)alkyl, wherein said (1-4C)alkyl, (1-4C)alkoxy, aryloxy, aryl, aryl(1-2C)alkyl, heteroaryl and heteroaryl(1-2C)alkyl are optionally substituted with one or more groups selected from the group consisting of halo, amino, hydroxy, (1-4C)alkyl and (1- 4C)alkoxy.
3. The compound of claim 1 or 2, wherein R1 is selected from the group consisting of aryloxy, aryl, aryl(1-2C)alkyl, heteroaryl and heteroaryl(1-2C)alkyl, wherein said aryloxy,
aryl, aryl(1-2C)alkyl, heteroaryl and heteroaryl(1-2C)alkyl are optionally substituted with one or more groups selected from the group consisting of halo, (1-4C)alkyl and (1- 4C)alkoxy.
4. The compound of claim 1 , 2 or 3, wherein R1 is selected from the group consisting of phenoxy, phenyl, benzyl, 6-membered heteroaryl and 6-membered heteroaryl(1- 2C)alkyl, wherein said phenoxy, phenyl, benzyl, 6-membered heteroaryl and 6- membered heteroaryl(1-2C)alkyl are optionally substituted with one or more groups selected from the group consisting of (1-4C)alkyl and (1-4C)alkoxy.
5. The compound of any preceding claim, wherein R1 is selected from the group consisting of phenoxy and phenyl, wherein said phenoxy and phenyl are optionally substituted with one or more groups selected from the group consisting of (1-4C)alkyl and (1-4C)alkoxy.
6. The compound of any preceding claim, wherein R1 is phenyl.
7. The compound of any preceding claim, wherein X is Zr.
8. The compound of any preceding claim, wherein each Y is independently selected from the group consisting of halo, (1-4C)alkyl, (1-4C)alkoxy and phenoxy, wherein said (1- 4C)alkyl, (1-4C)alkoxy and phenoxy are optionally substituted with one or more groups selected from the group consisting of halo and (1-4C)alkyl.
9. The compound of any preceding claim, wherein each Y is independently selected from the group consisting of halo and (1-4C)alkyl, wherein said (1-4C)alkyl is optionally substituted with one or more groups selected from the group consisting of halo and (1- 2C) alkyl.
10. The compound of any preceding claim, wherein each Y is independently selected from the group consisting of halo and (1-2C)alkyl.
11. The compound of any preceding claim, wherein each Y is independently selected from the group consisting of Cl and methyl.
12. The compound of any preceding claim, wherein both Y are identical.
13. The compound of any preceding claim, wherein the compound has a structure according to formula la shown below:
Ph denotes phenyl; and
Q is selected from the group consisting of absent, O and (CH2)n, wherein n is 1 or 2.
14. The compound of any preceding claim, wherein the compound has a structure
according to formula lb shown below:
Ph denotes phenyl; and
Q is selected from the group consisting of absent, O and (CH2)„, wherein n is 1 or 2.
15. The compound of any preceding claim, wherein the compound has a structure
according to formula lc shown below:
wherein
Ph denotes phenyl; and
Q is selected from the group consisting of absent, O and (CH2)n, wherein n is i or 2.
16. The compound of any preceding claim, wherein the compound has the following
structure:
17. A process for the ring opening polymerisation (ROP) of a cyclic ester, the process comprising the step of contacting a compound as defined in any preceding claim with one or more cyclic esters.
18. The process of claim 17, wherein the cyclic ester is selected from the group consisting of lactides and lactones.
19. The process of claim 17 or 18, wherein the cyclic ester is a lactide having any one of the following structures:
20. The process of claim 17, 18 or 19, wherein the compound of formula I is used with a hydroxylated activator compound.
21. The process of claim 20, wherein the hydroxylated activator compound is selected from the group consisting of tert-butanol, benzyl alcohol and iso-propanol.
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| GB1820100.4 | 2018-12-10 |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0629631A2 (en) * | 1993-06-07 | 1994-12-21 | Mitsui Petrochemical Industries, Ltd. | Novel transition metal compound, and polymerization catalyst containing it |
| WO2016075488A1 (en) * | 2014-11-13 | 2016-05-19 | Scg Chemicals Co., Ltd. | Catalysts |
| WO2016075486A1 (en) * | 2014-11-13 | 2016-05-19 | Scg Chemicals Co., Ltd. | Catalysts |
| WO2017060691A1 (en) | 2015-10-06 | 2017-04-13 | Scg Chemicals Co., Ltd. | Use of compounds in polymerisation reactions |
-
2018
- 2018-12-10 GB GBGB1820100.4A patent/GB201820100D0/en not_active Ceased
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2019
- 2019-12-06 WO PCT/GB2019/053446 patent/WO2020120936A1/en active Application Filing
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0629631A2 (en) * | 1993-06-07 | 1994-12-21 | Mitsui Petrochemical Industries, Ltd. | Novel transition metal compound, and polymerization catalyst containing it |
| WO2016075488A1 (en) * | 2014-11-13 | 2016-05-19 | Scg Chemicals Co., Ltd. | Catalysts |
| WO2016075486A1 (en) * | 2014-11-13 | 2016-05-19 | Scg Chemicals Co., Ltd. | Catalysts |
| WO2017060691A1 (en) | 2015-10-06 | 2017-04-13 | Scg Chemicals Co., Ltd. | Use of compounds in polymerisation reactions |
Non-Patent Citations (3)
| Title |
|---|
| REETZ M T ET AL: "DONOR COMPLEXES OF BIS(1-INDENYL)PHENYLBORANE DICHLOROZIRCONIUM AS ISOSPECIFIC CATALYSTS IN PROPENE POLYMERIZATION", CHEMICAL COMMUNICATIONS, ROYAL SOCIETY OF CHEMISTRY, UK, 1 January 1999 (1999-01-01), XP000826595, ISSN: 1359-7345, DOI: 10.1039/A902543J * |
| WENSHAN REN ET AL., INORGANIC CHEMISTRY COMMUNICATIONS, vol. 30, 2013, pages 26 - 28 |
| YALAN NING ET AL., ORGANOMETALLICS, vol. 27, 2008, pages 5632 - 5640 |
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