Catalysts and methods for polymer synthesis

• US 8,946,109 B2
• Filed: 01/31/2013
• Issued: 02/03/2015
• Est. Priority Date: 08/22/2008
• Status: Active Grant

• Current Assignee: Saudi Aramco Technologies Company
• Original Assignee: Novomer, Inc (Danimer Scientific, Inc.)
• Inventors: Allen, Scott D., Cherian, Anna E., Simoneau, Chris A., Farmer, Jay J., Coates, Geoffrey W., Gridnev, Alexei, LaPointe, Robert E.
• Primary Examiner(s): Truong, Duc
• Application Number:
  US13/755,120
• Publication Number:
  US 20130144032A1
• Time in Patent Office: 733 Days
• Field of Search: 502/102, 502/104, 528/405, 528/412, 528/480
• US Class Current: 502/102
• CPC Class Codes: B01J 2531/0238 Complexes comprising multidentate ligands, i.e. more than 2 ionic or coordinative bonds from the central metal to the ligand, the latter having at least two donor atoms, e.g. N, O, S, P
• CPC Class Codes: B01J 2531/025 Ligands with a porphyrin ring system or analogues thereof, e.g. phthalocyanines, corroles
• CPC Class Codes: B01J 2531/0252 Salen ligands or analogues, e.g. derived from ethylenediamine and salicylaldehyde
• CPC Class Codes: B01J 2531/0294 "Non-innocent" or "non-spectator" ligands, i.e. ligands described as, or evidently, taking part in the catalytic reaction beyond merely stabilizing the central metal as spectator or ancilliary ligands, e.g. by electron transfer to or from the central metal or by intra-/intermolecular chemical reactions, e.g. disulfide coupling, H-abstraction
• CPC Class Codes: B01J 2531/31 Aluminium
• CPC Class Codes: B01J 2531/62 Chromium
• CPC Class Codes: B01J 2531/845 Cobalt
• CPC Class Codes: B01J 31/0239 Quaternary ammonium compounds
• CPC Class Codes: B01J 31/0259 comprising phosphorous acid (-ester) groups ((RO)P(OR')2) or the isomeric phosphonic acid (-ester) groups (R(R'O)2P=O), i.e. R= C, R'= C, H
• CPC Class Codes: B01J 31/0265 Phosphazenes, oligomers thereof or the corresponding phosphazenium salts polyphosphazenes per se C07F9/067
• CPC Class Codes: B01J 31/182 comprising aliphatic or saturated rings
• CPC Class Codes: B01J 31/183 with more than one complexing nitrogen atom, e.g. phenanthroline
• CPC Class Codes: B01J 31/1835 comprising aliphatic or saturated rings
• CPC Class Codes: B01J 31/2243 At least one oxygen and one nitrogen atom present as complexing atoms in an at least bidentate or bridging ligand
• CPC Class Codes: C07C 251/24 having carbon atoms of imino groups bound to carbon atoms of six-membered aromatic rings
• CPC Class Codes: C07C 2601/14 The ring being saturated
• CPC Class Codes: C07C 279/12 being further substituted by nitrogen atoms not being part of nitro or nitroso groups
• CPC Class Codes: C07D 213/53 Nitrogen atoms
• CPC Class Codes: C07D 487/04 Ortho-condensed systems
• CPC Class Codes: C07D 487/22 in which the condensed system contains four or more hetero rings
• CPC Class Codes: C07F 15/065 : without a metal-carbon linkage
• CPC Class Codes: C07F 19/005 : without metal-C linkages
• CPC Class Codes: C07F 9/5355 : Phosphoranes containing the structure P=N-
• CPC Class Codes: C07F 9/6561 : containing systems of two or more relevant hetero rings condensed among themselves or condensed with a common carbocyclic ring or ring system, with or without other non-condensed hetero rings
• CPC Class Codes: C08F 4/80 : selected from iron group metals or platinum group metals
• CPC Class Codes: C08G 64/34 : and cyclic ethers

Abstract

The present invention provides unimolecular metal complexes having increased activity in the copolymerization of carbon dioxide and epoxides. Also provided are methods of using such metal complexes in the synthesis of polymers. According to one aspect, the present invention provides metal complexes comprising an activating species with co-catalytic activity tethered to a multidentate ligand that is coordinated to the active metal center of the complex.

Claims

1. A metal complex of the formula:

2. The metal complex of claim 1, wherein the activating moiety comprises an amidinium group.

3. The metal complex of claim 2, wherein the amidinium group has a formula:

4. The metal complex of claim 3, wherein each occurrence of R¹ and R² is independently an optionally substituted C_1-20 aliphatic group.

5. The metal complex of claim 3, wherein each occurrence of R¹ and R² is independently an optionally substituted phenyl group.

6. The metal complex of claim 3, wherein R¹ and R² are taken together with intervening atoms to form one or more optionally substituted rings.

7. The metal complex of claim 6, wherein R¹ and R² are taken together to form a ring fragment selected from the group consisting of:

—

C(R^y)₂—

, —

C(R^y)₂C(R^y)₂—

, —

C(R^y)₂C(R^y)₂C(R^y)₂—

, —

C(R^y)₂OC(R^y)₂—

, and —

C(R^y)₂NR^yC(R^y)₂—

, wherein each occurrence of R^y is independently -H, or an optionally substituted radical selected from the group consisting of C₁-₆ aliphatic, 3- to 7-membered heterocyclic, phenyl, and 8- to 10- membered aryl.

8. The metal complex of claim 7, wherein R¹ and R² are taken together to form a ring fragment selected from the group consisting of:

—

CH₂—

, —

CH₂CH₂—

, —

CH₂CH₂CH₂—

, —

CH₂OCH₂—

, and —

CH₂NR^yCH₂—

.

9. The metal complex of claim 8, wherein the resulting nitrogen-containing ring formed by the combination of R¹ and R² is partially unsaturated.

10. The metal complex of claim 8, wherein the resulting nitrogen-containing ring formed by the combination of R¹ and R² comprises a fused polycyclic heterocycle.

11. The metal complex of claim 3, wherein R⁵ is H.

12. The metal complex of claim 3, wherein R⁵ is optionally substituted C_1-20 aliphatic.

13. The metal complex of claim 3, wherein R⁵ is optionally substituted C_1-6 aliphatic.

14. The metal complex of claim 3, wherein one or more R¹ or R² groups are taken together with R⁵ and intervening atoms to form an optionally substituted ring.

15. The metal complex of claim 14, wherein R¹ and R⁵ are taken together to form an optionally substituted 5- or 6-membered ring.

16. The metal complex of claim 14, wherein R² and R⁵ are taken together to form an optionally substituted 5- or 6-membered ring optionally containing one or more additional heteroatoms.

17. The metal complex of claim 3, wherein R¹, R² and R⁵ are taken together to form an optionally substituted fused ring system.

18. The metal complex of claim 17, wherein a ring in the fused ring system formed by combinations of any of R¹, R² and R⁵ is partially unsaturated or aromatic.

19. The metal complex of claim 1, wherein the activating moiety comprises an amidine.

20. The metal complex of claim 19, wherein the amidine has a formula:

21. The metal complex of claim 20, wherein each R¹ and R² is independently an optionally substituted radical selected from the group consisting of C_1-20 aliphatic;

C_1-20 heteroaliphatic, 5- to 14-membered heteroaryl, phenyl, 8- to 10-membered aryl and 3- to 7-membered heterocyclic.

22. The metal complex of claim 20, wherein R¹ and R² are each independently an optionally substituted radical selected from the group consisting of C_1-12 aliphatic and C_1-12 heteroaliphatic.

23. The metal complex of claim 20, wherein each occurrence of R¹ and R² is independently an optionally substituted C_1-12 aliphatic.

24. The metal complex of claim 20, wherein R¹ and R² are each independently optionally substituted C_1-6 aliphatic.

25. The catalyst of claim 20, wherein R¹ and R² are both methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, phenyl or benzyl.

26. The metal complex of claim 20, wherein R¹ and R² are taken together with intervening atoms to form one or more optionally substituted rings.

27. The metal complex of claim 26, wherein R¹ and R² are taken together to form a ring fragment selected from the group consisting of:

—

C(R^y)₂—

, —

C(R^y)₂C(R^y)₂—

, —

C(R^y)₂C(R^y)₂C(R^y)₂—

, —

C(R^y)₂OC(R^y)₂—

, and —

C(R^y)₂NR^yC(R^y)₂—

, wherein each occurrence of R^y is independently -H, or an optionally substituted radical selected from the group consisting of C₁-₆ aliphatic, 3- to 7-membered heterocyclic, phenyl, and 8- to 10- membered aryl.

28. The metal complex of claim 27, wherein R¹ and R² are taken together to form a ring fragment selected from the group consisting of:

—

CH₂—

, —

CH₂CH₂—

, —

CH₂CH₂CH₂—

, —

CH₂OCH₂—

, and —

CH₂NR^yCH₂—

.

29. The metal complex of claim 20, wherein R⁵ is H.

30. The metal complex of claim 20, wherein R⁵ is optionally substituted C_1-12 aliphatic.

31. The metal complex of claim 20, wherein R⁵ is optionally substituted phenyl.

32. The metal complex of claim 20, wherein one or more R¹ or R² groups are taken together with R⁵ and intervening atoms to form an optionally substituted ring.

33. The metal complex of claim 32, wherein R¹ and R⁵ are taken together to form an optionally substituted 5- or 6-membered ring.

34. The metal complex of claim 33, wherein R¹, R² and R⁵ are taken together to form an optionally substituted fused ring system.

35. The metal complex of claim 34, wherein a ring formed by combinations of any of R¹, R² and R⁵ is partially unsaturated or aromatic.

36. The metal complex of claim 20, wherein the amidine is selected from the group consisting of:

37. The metal complex of claim 1, wherein

38. The metal complex of claim 1, wherein

39. The metal complex of claim 38, wherein the catalyst comprises a substructure conforming to a formula selected from the group consisting of:

40. The metal complex of claim 39, wherein comprises an optionally substituted C_2-30 aliphatic group wherein one or more methylene units are optionally and independently replaced by —

NR^y—

, —

N(R^y)C(O)—

, —

C(O)N(R^y)—

, —

O—

, —

C(O)—

, —

OC(O)—

, —

C(O)O—

, —

S—

, —

SO—

, —

SO₂—

, —

C(═

S)—

, —

C(═

NR^y)—

, or —

N═

N—

, where each occurrence of R^y is independently —

H, or an optionally substituted radical selected from the group consisting of C_1-6 aliphatic 3- to 7-membered heterocyclic, phenyl, and 8- to 10-membered aryl.

41. The metal complex of claim 39, wherein comprises a C_3-30 aliphatic group.

42. The metal complex of claim 39, wherein comprises a C_4-8 aliphatic group.

43. The metal complex of claim 39, wherein comprises a C₃ aliphatic group.

44. The metal complex of claim 39, wherein is selected from the group consisting of:

45. The metal complex of claim 37, wherein X′

is selected from the group consisting of;

chlorine, bromine, an optionally substituted C_1-12 carboxylate, azide, an optionally substituted phenoxide, and sulfonate.

46. The metal complex of claim 37, wherein X′

is selected from the group consisting of;

chloride, acetate, trifluoroacetate, azide, pentafluorobenzoate, and a nitrophenolate.

47. A method for the synthesis of aliphatic polycarbonate polymers comprising the step of contacting one or more epoxides with carbon dioxide in the presence of a metal complex of claim 1.

48. The method of claim 47, where the activating moiety comprises an amidinium group.

49. The method of claim 47, where the activating moiety comprises an amidine group.

50. The method of claim 47, wherein the epoxide is ethylene oxide, propylene oxide, or cyclohexene oxide.

51. The method of claim 47, wherein the epoxide is ethylene oxide.

52. The method of claim 47, wherein the epoxide is propylene oxide.

53. The method of claim 47, wherein a pressure of carbon dioxide is between about 50 and 800 psi.

54. The method of claim 47, wherein a molar ratio of catalyst to epoxide is between about 1:

1000 and about 1;

100,000.