Catalysts and methods for polymer synthesis

A method comprising the step of contacting an epoxide and carbon dioxide with a bimetallic complex having the structure:

• wherein:
• M1 is a first metal atom;
• M2 is a second metal atom;
• comprises a multidentate ligand system capable of coordinating both metal atoms;
• represents one or more activating moieties attached to the multidentate ligand system, where
• is a linker moiety covalently coupled to the ligand system, m is an integer from 1 to 4 representing the number of Z groups present on an individual linker moiety;
• and each (Z) is an activating functional group independently selected from the group consisting of:
• wherein:
• each R1 and R2 is independently hydrogen or an optionally substituted radical selected from the group consisting of C1-20 aliphatic;
• C1-20 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 nitrogen, oxygen, or sulfur;
• an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• phenyl;
• or an 8- to 14-membered polycyclic aryl ring;
• wherein R1 and R2 can be taken together with intervening atoms to form one or more optionally substituted rings optionally containing one or more additional heteroatoms;
• each R3 is independently hydrogen or an optionally substituted radical selected from the group consisting of C1-20 aliphatic;
• C1-20 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 nitrogen, oxygen, or sulfur;
• an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• phenyl;
• or an 8- to 14-membered polycyclic aryl ring;
• wherein an R3 group can be taken with an R1 or R2 group to form one or more optionally substituted rings;
• and
• each R4 is independently hydrogen, a hydroxyl protecting group, or an optionally substituted radical selected from the group consisting of C1-20 acyl;
• C1-20 aliphatic;
• C1-20 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 nitrogen, oxygen, or sulfur;
• an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• phenyl;
• or an 8- to 14-membered polycyclic aryl ring;
• R5 is R2 or hydroxyl;
• wherein R1 and R5 can be taken together with intervening atoms to form one or more optionally substituted carbocyclic, heterocyclic, aryl, or heteroaryl rings;
• each R6 and R7 is independently hydrogen or an optionally substituted radical selected from the group consisting of C1-20 aliphatic;
• C1-20 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 nitrogen, oxygen, or sulfur;
• an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• phenyl;
• or an 8- to 14-membered polycyclic aryl ring;
• wherein R6 and R7 can be taken together with intervening atoms to form one or more optionally substituted rings optionally containing one or more heteroatoms, and an R6 and R7 group can be taken with an R1 or R2 group to form one or more optionally substituted rings;
• each occurrence of R8 is independently selected from the group consisting of:
• halogen, —NO2, —CN, —SRy, —S(O)Ry, —S(O)2Ry, —NRyC(O)Ry, —OC(O)Ry, —CO2Ry, —NCO, —N3, —OR7, —OC(O)N(Ry)2, —N(Ry)2, —NRyC(O)Ry, —NRyC(O)ORy;
• or an optionally substituted radical selected from the group consisting of C1-20 aliphatic;
• C1-20 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 nitrogen, oxygen, or sulfur;
• an 8- to 14-membered polycyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 3- to 8-membered saturated or partially unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 6- to 14-membered saturated or partially unsaturated polycyclic heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• phenyl;
• or an 8- to 14-membered polycyclic aryl ring;
• and where two or more adjacent R8 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;
• each Ry is independently —H, or an optionally substituted radical selected from the group consisting of C1-6 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 nitrogen, oxygen, or sulfur, a 5-6 membered heteroaryl ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur, and 8- to 10-membered aryl;
• X− is any anion;
• 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 nitrogen, oxygen, or sulfur.