Catalysts and methods for polymer synthesis

A metal complex:

• wherein:
• R2a and R2a′, are independently a (Z)m group,
• hydrogen, —OR, —NR2, —SR, —CN, —NO2, —SO2R, —SOR, —SO2NR2;
• —CNO, —NRSO2R, —NCO, —N3, —SiR3;
• or an optionally substituted radical selected from the group consisting of C1-20 aliphatic;
• C1-20 heteroaliphatic;
• phenyl;
• a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle;
• a 7-14 carbon saturated, partially unsaturated or aromatic polycyclic carbocycle;
• a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 3- to 8-membered saturated or partially unsaturated heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 6- to 12-membered polycyclic saturated or partially unsaturated heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• and an 8- to 10-membered bicyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• R1a, R1a′, R3a, and R3a′ are independently a (Z)m group hydrogen, or an optionally substituted radical selected from the group consisting of C1-20 aliphatic;
• C1-20 heteroaliphatic;
• phenyl;
• a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle a 7-14 carbon saturated, partially unsaturated or aromatic polycyclic carbocycle;
• a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 3- to 8-membered saturated or partially unsaturated heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 6- to 12-membered polycyclic saturated or partially unsaturated heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• and an 8- to 10-membered bicyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur, where any of [R2a′ and R3a′], [R2a and R3a], [R1a and R2a], and [R1a′ and R2a′] may optionally be taken together with intervening atoms to form one or more rings which may in turn be substituted with one or more Rd groups;
• R4b is selected from the group consisting of:
• Rc at each occurrence is independently a (Z)m group, hydrogen, halogen, —OR, —NR2, —SR, —CN, —NO2, —SO2R, —SOR, —SO2NR2;
• —CNO, —NRSO2R, —NCO, —N3, —SiR3;
• or an optionally substituted radical selected from the group consisting of C1-20 aliphatic;
• C1-20 heteroaliphatic;
• phenyl;
• a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle a 7-14 carbon saturated, partially unsaturated or aromatic polycyclic carbocycle;
• a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 3- to 8-membered saturated or partially unsaturated heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 6- to 12-membered polycyclic saturated or partially unsaturated heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• and an 8- to 10-membered bicyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• where two or more le groups may be taken together with the carbon atoms to which they are attached and any intervening atoms to form one or more optionally substituted rings;
• when two le groups are attached to the same carbon atom, they may optionally be taken together along with the carbon atom to which they are attached to form an optionally substituted moiety selected from the group consisting of:
• a 3- to 8-membered spirocyclic ring, a carbonyl, an oxime, a hydrazone, and an imine;
• Rd at each occurrence is independently a (Z)m group, hydrogen,
• halogen, —OR, —NR2, —SR, —CN, —NO2, —SO2R, —SOR, —SO2NR2;
• —CNO, —NRSO2R, —NCO, —N3, —SiR3;
• or an optionally substituted radical selected from the group consisting of C1-20 aliphatic;
• C1-20 heteroaliphatic;
• phenyl;
• a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle;
• a 7-14 carbon saturated, partially unsaturated or aromatic polycyclic carbocycle;
• a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 3- to 8-membered saturated or partially unsaturated heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 6- to 12-membered polycyclic saturated or partially unsaturated heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• and an 8- to 10-membered bicyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• where two or more Rd groups may be taken together with intervening atoms to form one or more optionally substituted rings optionally containing one or more heteroatoms,
• R at each occurrence is independently hydrogen or an optionally substituted radical selected the group consisting of acyl;
• C1-6 aliphatic;
• C1-6 heteroaliphatic;
• carbamoyl;
• arylalkyl;
• phenyl;
• a 3- to 8-membered saturated or partially unsaturated monocyclic carbocycle a 7-14 carbon saturated, partially unsaturated or aromatic polycyclic carbocycle;
• a 5- to 6-membered monocyclic heteroaryl ring having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 3- to 8-membered saturated or partially unsaturated heterocyclic ring having 1-3 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• a 6- to 12-membered polycyclic saturated or partially unsaturated heterocycle having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• an 8- to 10-membered bicyclic heteroaryl ring having 1-5 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• an oxygen protecting group;
• and a nitrogen protecting group, where two R groups on the same nitrogen atom can optionally be taken together to form an optionally substituted 3- to 7-membered ring,
• X is a nucleophile capable of ring opening an epoxide;
• Y is a divalent linker selected from the group consisting
• of:
• —NR—, —N(R)C(O)—, —C(O)NR—, —O—, —C(O)—, —OC(O)—, —C(O)O—, —S—, —SO—, —SO2—, —SiR2—, —C(═S)—, —C(═NR)—, or —N═N—;
• a polyether;
• a C3 to C8 substituted or unsubstituted carbocycle;
• and a C1 to C8 substituted or unsubstituted heterocycle;
• m′ is 0 or an integer from 1 to 4, inclusive;
• q is 0 or an integer from 1 to 4, inclusive;
• x is 0, 1, or 2;
• and
• (Z)m represents one or more activating moieties tethered to the multidentate ligand, where represents a linker moiety;
• m represents the number of Z groups present on a linker moiety and is an integer between 1 and 4 inclusive;
• and each (Z) represents an activating moiety.