Enantioselective hydrolytic kinetic resolution of epoxides catalyzed by chiral Co(III) salen complexes immobilized in the membrane reactor

The supported ZSM-5 film was synthesized hydrothermally on the porous supports such as Anodisc and alumina tube. The enantioselective hydrolytic resolution of racemic epoxides was performed in the ZSM-5/Anodisc membrane reactor containing chiral salen complexes. The chiral (Co-salen)+PF6- and (Co-salen)+BF4- complexes immobilized on the membrane showed a very high enantioselectivity and recyclability in the hydrolysis of epichlorohydrine, 1,2-epoxybutane, 1,2-epoxyhexane and styrene oxide. It was easy to separate the products, and the catalysts could be recycled without observable loss in activity and enantioselectivity using the batch-type and continuous-type membrane reactor. The obtained epoxide product remained in the organic phase and the hydrophilic water-soluble diols diffused into the aqueous phase through the ZSM-5 film layer.