Synthesis of polymeric salen complexes and application in the enantioselective hydrolytic kinetic resolution of epoxides as catalysts

The polymeric (salen) Co(III) catalysts containing various counter anions have been synthesized, and the asymmetric catalytic activities of these newly synthesized polymer-type salen complexes were investigated in the HKR of terminal epoxides. The polymeric chiral salen Co(III) complexes catalyze the hydrolysis of epichlorohydrine, 1,2-epoxybutane, 1,2-epoxyhexane and epoxystyrene with very high enantioselectivities under mild conditions. The catalysts could be recovered and reused several times without further treatment after reaction, showing no loss of activity and enantioselectivity.