Preparation of MCM-41 Supported Heterogenized Chiral Salen Mn (III) Complex and the Catalytic Activity in the Asymmetric Epoxidation

A chiral Manganese (III) salen complex was immobilized on the walls of MCM-41 (mobile crystalline material) through the multi-grafting method. The immobilized complex was characterized by XRD, FTIR, UV-Vis, ICP and Nitrogen sorption, and was applied to the asymmetric epoxidation of unfuctionalized alkenes including 1,2-dihydronaphthalene, α-methylstyrene, cis-β-methylstyrene, styrene using NaClO and m-chloroperbenzoic acid (m-CPBA) as oxidants respectively. The immobilized complex showed good activity and enantioselectivity in the epoxidation of 1,2-dihydronaphthalene by using NaClO as oxidant. It could also be run for 4 times in the epoxidation of α-methylstyrene without obvious loss of activity or enantiomeric excess.