Iron complexes and methods for polymerization

摘要

Provided are methods of preparing polymers, such as polyisoprene, polybutadiene, polypiperylene, polycyclohexadiene, poly-β-farnesene, or poly-β-myrcene, using iron complexes. Also provided are novel iron complexes, pre-catalysts, intermediates, and ligands useful in the inventive polymerization system.

主权项

1. A method of preparing a polymer, the method comprising polymerizing one or more alkenes in the presence of an iron complex, wherein the iron complex comprises a ligand of the Formula (BI-a):wherein:
m is 0 or 1, provided that when m is 0, X is selected from N—R4; and when m is 1, X is selected from N or C—R4; each instance of R1, R2, R3, R4, and R5 is independently selected from the group consisting of hydrogen, halogen, —CN, —NO2, —N3, —SO2H, —SO3H, —OH, —SH, —NH2, substituted hydroxyl, substituted thiol, monosubstituted amino, disubstituted amino, trisubstituted amino, sulfonyl, sulfinyl, carbonyl, silyl, phosphino, boronyl, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted carbocyclyl, optionally substituted heterocyclyl, optionally substituted aryl, and optionally substituted heteroaryl; or R1 and R2, or R2 and R3, or R2 and R4, or R3 and R4, are optionally joined to form a ring selected from the group consisting of optionally substituted carbocyclyl, optionally substituted heterocyclyl, optionally substituted aryl, and optionally substituted heteroaryl ring; R7 is optionally substituted aryl or optionally substituted —CH2aryl; R8 and R9 are each independently selected from the group consisting of hydrogen, halogen, —CN, —NO2, —N3, —SO2H, —SO3H, —OH, —SH, —NH2, substituted hydroxyl, substituted thiol, monosubstituted amino, disubstituted amino, trisubstituted amino, sulfonyl, sulfinyl, carbonyl, silyl, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted carbocyclyl, optionally substituted heterocyclyl, optionally substituted aryl, and optionally substituted heteroaryl, and the one or more alkenes are independently an optionally substituted 1,3-diene of formula (i):wherein:
each instance of Ra, Rb, Rc, Rd, Re, and Rf is independently selected from the group consisting of hydrogen, silyl, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted carbocyclyl, optionally substituted heterocyclyl, optionally substituted aryl, and optionally substituted heteroaryl; or Ra and Rf are joined to form an optionally substituted heterocyclyl or optionally substituted carbocyclyl ring.