Cobalt-based complexes for the copolymerization of propylene oxide and CO2:: Active and selective catalysts for polycarbonate synthesis

CO2 is an ideal feedstock for chemical synthesis; unfortunately its thermodynamic stability is a barrier to widespread use. Active cobalt catalysts for the copolymerization of propylene oxide and CO2 are reported (see scheme; L = N,N′ -bis(3,5-di-tert-butylsalicylidene)-1,2-cyclo-hexanediamine), which have excellent regioselectivity for polycarbonate synthesis without concomitant production of cyclic carbonate by-products.