Catalytic carbonylation catalysts and methods
In one aspect, the present invention provides catalysts for the carbonylation of heterocycles. The inventive catalysts feature metal-ligand complexes having cationic functional groups tethered to the ligand, wherein the tethered cationic groups are associated with anionic metal carbonyl species. The invention also provides methods of using the inventive catalysts to affect the ring opening carbonylation of epoxides.
1. A catalyst for the carbonylation of heterocycles comprising the combination of:
i) one or more cationic functional moieties, where each cationic functional moiety independently comprises a linker and 1 to 4 cationic functional groups;
ii) a tetraphenyl porphyrin ligand to which at least one cationic functional moiety is covalently tethered; and
iii) at least one anionic metal carbonyl species associated with a cation functional group.
2. The catalyst of claim 1 , wherein the catalyst comprises a tetraphenyl porphyrin complex of a metal selected from the group consisting of: Zn(II), Cu(II), Mn(II), Co(II), Ru(II), Fe(II), Co(II), Rh(II), Ni(II), Pd(II), Mg(II), Al(III), Cr(III)—Cr(IV), Ti(IV), Fe(III), Co(III), Ti(III), In(III), Ga(III), and Mn(III).
3. The catalyst of claim 1 , wherein the catalyst comprises a tetraphenyl porphyrin complex of aluminum.
4. The catalyst of claim 1 , wherein the catalyst comprises a tetraphenyl porphyrin complex of chromium.
5. The catalyst of claim 1 , wherein one or more cationic functional groups comprise onium salts.
6. The catalyst of claim 5 , wherein the onium salts comprise at least one of nitrogen and phosphorous.
7. The catalyst of claim 1 , wherein the one or more cationic functional groups are independently selected from the group consisting of:
wherein:
each R 1 and R 2 is independently hydrogen or an optionally substituted radical selected from the group consisting of C 1-20 aliphatic; C 1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; phenyl; and an 8- to 14-membered polycyclic aryl ring; or wherein R 1 and R 2 can be taken together with intervening atoms to form one or more optionally substituted rings optionally containing one or more additional heteroatoms;
each R 3 is independently hydrogen or an optionally substituted radical selected from the group consisting of C 1-20 aliphatic; C 1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; phenyl; and an 8- to 14-membered polycyclic aryl ring; or wherein an R 3 group can be taken with an R 1 or R 2 group to form one or more optionally substituted rings; and
R 5 is R 2 or hydroxyl; or wherein R 1 and R 5 can be taken together with intervening atoms to form one or more optionally substituted carbocyclic, heterocyclic, aryl, or heteroaryl rings;
each R 6 and R 7 is independently hydrogen or an optionally substituted radical selected from the group consisting of C 1-20 aliphatic; C 1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; phenyl; and an 8- to 14-membered polycyclic aryl ring; or wherein R 6 and R 7 can be taken together with intervening atoms to form one or more optionally substituted rings optionally containing one or more heteroatoms, or an R 6 and R 7 group can be taken with an R 1 or R 2 group to form one or more optionally substituted rings;
each occurrence of R 8 is independently selected from the group consisting of: halogen, —NO 2 , —CN, —SR y , —S(O)R y , —S(O) 2 R y , —NR y C(O)R y , —OC(O)R y , —CO 2 R y , —NCO, —N 3 , —OR 7 , —OC(O)N(R y ) 2 , —N(R y ) 2 , —NR y C(O)R y , —NR y C(O)OR y ; an optionally substituted radical selected from the group consisting of C 1-20 aliphatic; C 1-20 heteroaliphatic; a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle; a 7- to 14-membered saturated or partially unsaturated polycyclic carbocycle; a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; phenyl; and an 8- to 14-membered polycyclic aryl ring; wherein each R y is independently —H, or an optionally substituted radical selected from the group consisting of C 1-6 aliphatic, phenyl, a 3-7 membered saturated or partially unsaturated carbocyclic ring, a 3-7 membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-2 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur, a 5-6 membered heteroaryl ring having 1-3 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur, and an 8- to 10-membered aryl, or wherein two or more adjacent R 8 groups can be taken together to form an optionally substituted saturated, partially unsaturated, or aromatic 5- to 12-membered ring containing 0 to 4 heteroatoms;
X − is any anionic metal carbonyl compound;
Ring A is an optionally substituted, 5- to 10-membered heteroaryl group; and
Ring B is an optionally substituted, 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 0-2 heteroatoms in addition to the depicted ring nitrogen atom independently selected from the group consisting of nitrogen, oxygen, and sulfur.
8. The catalyst of claim 7 , wherein one or more cationic functional groups are selected from the group consisting of:
9. The catalyst of claim 8 , wherein one or more cationic functional groups are selected from the group consisting of:
10. The catalyst of claim 8 , wherein one or more cationic functional groups are selected from the group consisting of:
11. The catalyst of claim 8 , wherein one or more cationic functional groups are selected from the group consisting of:
12. The catalyst of claim 1 , wherein each cationic functional moiety is independently a bond, or a moiety comprising 1-30 atoms including at least one carbon atom and optionally one or more atoms selected from the group consisting of N, O, S, Si, B, and P.
13. The catalyst of claim 12 , wherein each cationic functional moiety comprises a linker comprising optionally substituted C 2-30 aliphatic group wherein one or more methylene units are optionally and independently replaced by:
-Cy-, —NR y —, —N(R y )C(O)—, —C(O)N(R y )—, —O—, —C(O)—, —OC(O)—, —C(O)O—, —S—, —SO—, —SO 2 —, —C(═S)—, —C(═NR y )—, or —N═N—,
wherein each -Cy- is independently an optionally substituted 5-8 membered bivalent, saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur, or an optionally substituted 8-10 membered bivalent saturated, partially unsaturated, or aryl bicyclic ring having 0-5 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; and
each R y is independently —H, or an optionally substituted radical selected from the group consisting of C 1-6 aliphatic, phenyl, a 3-7 membered saturated or partially unsaturated carbocyclic ring, a 3-7 membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-2 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur, a 5-6 membered heteroaryl ring having 1-3 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur, and an 8- to 10-membered aryl.
14. The catalyst of claim 1 , wherein the at least one anionic metal carbonyl species is a compound of formula: [Q d M′ e (CO) w ] y− , where Q is a ligand and need not be present, M′ is a metal atom, d is an integer between 0 and 8 inclusive, e is an integer between 1 and 6 inclusive, w is a number such as to provide a stable anionic metal carbonyl complex, and y is the charge of the anionic metal carbonyl compound.
15. The catalyst of claim 1 , wherein the at least one anionic metal carbonyl species is selected from the group consisting of: monoanionic carbonyl complexes of metals from groups 5, 7 or 9 of the periodic table, and dianionic carbonyl complexes of metals from groups 4 or 8 of the periodic table.
16. The catalyst of claim 1 , wherein the at least one anionic metal species is selected from the group consisting of: [Co(CO) 4 ] − , [Ti(CO) 6 ] 2− , [V(CO) 6 ] − , [Rh(CO) 4 ] − , [Fe(CO) 4 ] 2− , [Ru(CO) 4 ] 2− , [Os(CO) 4 ] 2− , [Cr 2 (CO) 10 ] 2 , [Fe 2 (CO) 8 ] 2− , [Tc(CO) 5 ] − , [Re(CO) 5 ] − , and [Mn(CO) 5 ] − .
17. The catalyst of claim 1 , wherein the at least one anionic carbonyl species is [Co(CO) 4 ] − .
18. The catalyst of claim 1 , wherein the tetraphenyl porphyrin ligand to which at least one cationic functional moiety is covalently tethered has a structure selected from the group consisting of:
where, each represents a cationic functional moiety, where is a bond or a linker moiety, Z is a cationic functional group, and b is an integer from 1 to 4 representing the number of cationic functional groups present on the cationic functional moiety;
M is a metal atom;
R d at each occurrence is independently a cationic functional moiety ( ), hydrogen, halogen, —OR 4 , —NR y 2 , —SR y , —CN, —NO 2 , —SO 2 R y , —SOR y , —SO 2 NR y 2 ; —CNO, —NRSO 2 R y , —NCO, —N 3 , —SiR y 3 ; an optionally substituted group selected from the group consisting of C 1-20 aliphatic; C 1-20 heteroaliphatic having 1-4 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; 6- to 10-membered aryl; 5- to 10-membered heteroaryl having 1-4 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; and 4- to 7-membered heterocyclic having 1-2 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur, or where two or more R d groups may be taken together to form one or more optionally substituted rings, where each R y is independently hydrogen, an optionally substituted group selected the group consisting of acyl; carbamoyl, arylalkyl; 6- to 10-membered aryl; C 1-12 aliphatic; C 1-12 heteroaliphatic having 1-2 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; 5- to 10-membered heteroaryl having 1-4 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; 4- to 7-membered heterocyclic having 1-2 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; an oxygen protecting group; and a nitrogen protecting group; or wherein two R y on the same nitrogen atom are taken with the nitrogen atom to form an optionally substituted 4- to 7-membered heterocyclic ring having 0-2 additional heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur; and
each R 4 is a hydroxyl protecting group or R y ;
each So is optionally present, and if present is a neutral two electron donor; and
a is an integer from 0 to 4 inclusive.
19. A catalyst for the carbonylation of heterocycles comprising a compound selected from the group consisting of:
wherein M is selected from the group consisting of:
20. A method comprising contacting ethylene oxide with carbon monoxide in the presence of a catalyst of claim 1 , to produce a product comprising beta propiolactone, succinic anhydride, or polypropiolactone, or a mixture thereof.
21. The method of claim 20 , wherein the product consists substantially of beta propiolactone.
22. The method claim 20 , wherein the product consists substantially of polypropiolactone.
23. The catalyst of claim 7 , wherein the linker of each cationic functional moiety is independently selected from the group consisting of:
wherein each s is independently 0-6, t is 0-4, each * represents the site of attachment to a ligand, and each # represents a site of attachment of a cationic functional group.