Copolymerization of Epoxides with Carbon Dioxide Catalyzed by Cobalt Complexes

摘要

The copolymerization of epoxides with CO2 has been intensively studied in the last decade as one of the most promising processes for CO2 utilization. Recently, a mixture of Co(salcy)OAc complex [salcyH2 = trans-N,N'-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediamine] and quaternary ammonium salt was reported to achieve the highest level of catalytic activity for the copolymerization of propylene oxide (PO) with CO2. However, as is the general incidental problem in the reaction of terminal epoxides, the concomitant production of cyclic carbonate proceeds at high epoxide conversion (>50%). Herein, we report the copolymerization of terminal epoxides with CO2 by using new cobalt complexes that can selectively produce the copolymer, even at high monomer conversion.