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 comprising:
i) a metal complex of formula (III-a), (III-b), (III-c), (IV-a), (IV-b), (IV-c), (V-a), (V-b), (VI-a), (VI-b), or (VI-c):
wherein:
R c , R d and R e at each occurrence is independently:
(Z + ) b , wherein:
is a bond or a linker;
Z + is a cationic functional group; and
b is an integer from 1 to 4 inclusive; or
hydrogen, halogen, —OR 4 , —NR y 2 , —SR y , —CN, —NO 2 , —SO 2 R y , —SOR y , —SO 2 NR y 2 ; —CNO, —NR y SO 2 R y , —NCO, —N 3 ; or 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 nitrogen, oxygen, or sulfur; and 4- to 7-membered heterocyclic having 1-2 heteroatoms independently selected from the group consisting of nitrogen, oxygen, and sulfur,
wherein two or more R c groups, or two or more R d groups may be taken together to form one or more optionally substituted rings,
wherein each R y is independently hydrogen, or 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;
R 4 is a hydroxyl protecting group or R y ;
R 12 is selected from the group consisting of: a (Z + ) b group; or an optionally substituted radical selected from the group consisting of C 1-20 aliphatic; C 1-20 heteroaliphatic; and phenyl; and
M 1 and M 2 comprise metal atoms, and may be the same or different; and
ii) at least one anionic metal carbonyl species associated with at least one of Z + .
2. The catalyst of claim 1 , wherein M 1 and M 2 are independently selected from the group consisting of Zn(II), Cu(II), Mn(II), Co(II), Ru(II), Fe(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 M 1 and M 2 are aluminum.
4. The catalyst of claim 1 , wherein M 1 and M 2 are chromium.
5. The catalyst of claim 1 , wherein Z + comprises an atom selected from the group consisting of nitrogen, phosphorous, arsenic, and sulfur.
6. The catalyst of claim 1 , wherein at least one anionic metal carbonyl species is X − and is associated with at least one of Z + , wherein Z + X − is selected from the group consisting of:
wherein:
each R 1 and R 2 is independently hydrogen or an optionally substituted group 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 are 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 group 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 are 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 are 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 group 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 are 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 are taken with an R 1 or R 2 group to form one or more optionally substituted rings;
each occurrence of R 8 is independently:
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 , or —NR y C(O)OR y ; or an optionally substituted group 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 group 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 are taken together to form an optionally substituted saturated, partially unsaturated, or aromatic 5- to 12-membered ring containing 0 to 4 heteroatoms;
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;
wherein:
when is a bond, is the site of attachment of Z + to the metal complex;
when is a linker, is the site of attachment of Z + to the linker.
7. The catalyst of claim 1 , wherein the linker comprises 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.
8. The catalyst of claim 1 , wherein the linker is an 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 group 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.
9. 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− , wherein:
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 species.
10. The catalyst of claim 9 , wherein Q is a phosphine ligand or a cyclopentadienyl (cp) ligand.
11. 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.
12. The catalyst of claim 1 , wherein the at least one anionic metal carbonyl 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 ] − .
13. The catalyst of claim 1 , wherein the at least one anionic metal carbonyl species is [Co(CO) 4 ].
14. A catalyst selected from the group consisting of:
wherein each M independently comprises a metal atom.
15. The catalyst of claim 14 , wherein each M is independently selected from the group consisting of Zn(II), Cu(II), Mn(II), Co(II), Ru(II), Fe(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).
16. The catalyst of claim 14 , wherein each M is independently aluminum or chromium.
17. A method comprising contacting ethylene oxide with carbon monoxide in the presence of a catalyst of claim 1 , to provide a product comprising beta propiolactone, succinic anhydride, or polypropiolactone, or a mixture of any two or more of these.
18. The method of claim 17 , wherein the product comprises beta propiolactone, polypropiolactone, or a combination thereof.
19. A method comprising contacting propylene oxide with carbon monoxide in the presence of a catalyst of claim 1 , to provide a product comprising beta butyrolactone, methyl succinic anhydride, or poly-3-hydroxybutyrate, or a mixture of any two or more of these.
20. The method of claim 19 , wherein the product comprises beta butyrolactone, poly-3-hydroxybutyrate, or combination thereof.
21. A method comprising contacting ethylene oxide with carbon monoxide in the presence of a catalyst of claim 14 , to provide a product comprising beta propiolactone, succinic anhydride, or polypropiolactone, or a mixture of any two or more of these.
22. The method of claim 21 , wherein the product comprises beta propiolactone, polypropiolactone, or a combination thereof.
23. A method comprising contacting propylene oxide with carbon monoxide in the presence of a catalyst of claim 14 , to provide a product comprising beta butyrolactone, methyl succinic anhydride, or poly-3-hydroxybutyrate, or a mixture of any two or more of these.
24. The method of claim 23 , wherein the product comprises beta butyrolactone, poly-3-hydroxybutyrate, or a combination thereof.