Metalloporphyrin catalysts for living and immortal polymerizations

The living polymerization of methyl methacrylate with aluminium porphyrin ( 1 ) proceeded dramatically rapidly at room temperature in the presence of sterically crowded organoaluminium compounds such as methylaluminium ortho ‐substituted diphenolates ( 3a − 3g ), bis(triphenylmethanolate) ( 4a ), and triphenylaluminium, where undesired reaction between the growing species and the Lewis acids was sterically suppressed. On the basis of this Lewis acid ‐ assisted high‐speed living polymerization, various monomers such as ethyl, propyl, butyl, and dodecyl methacrylates, methacrylonitrile, and 1,2‐epoxypropane were polymerized very rapidly with the aluminium porphyrin ‐ Lewis acid systems.