Cobalt-Catalyzed Carbonylative Polymerization of Oxetane

Abstract

Copolymerization of oxetanes with carbon monoxide (CO) provided polymers consisting of both ester and ether units. Four acetylcobalt complexes, AcCo(CO)3P(p-tolyl)3 (1), AcCo(CO)3P(OPh)3 (2), AcCo(CO)3P(NMe2)3 (3), and AcCo(CO)2dppp (4) were synthesized, characterized, and examined as catalysts. Copolymers were obtained with complexes 1 and 2 while no reaction proceeded with complexes 3 and 4. The higher ester/ether ratio and the lower molecular weight of copolymers obtained with 1 compared to those with 2 were attributed to the electron-donating nature of P(p-tolyl)3.</p