Asymmetric epoxidation of unfactionalized olefins catalyzed by chiral salen Mn(III) immobilized onto sulfoalkyl modified zirconium poly(styrene-isopropenyl phosphonate)-phosphate and zirconium poly(styrene-phenylvinyl phosphonate)-phosphate

Chiral salen Mn(III) complex has been supported onto sulfoalkyl-modified zirconium poly(styrene-isopropenyl phosphonate)-phosphate and zirconium poly(styrene-phenylvinyl phosphonate)-phosphate (ZPS-IPPA and ZPS-PVPA) by axial coordination. The supported catalysts showed higher chiral induction for enantioselective epoxidation of styrene, α-methylstyrene and indene than its homogeneous chiral salen Mn(III). In addition, ZPS-PVPA-supported catalyst (4c), with a larger pore diameter, was found to be more active than ZPS-IPPA-based catalyst (3c). The influence of the linkage lengths on the catalytic performance was investigated. Whatʹs more, the catalysts were easily separated from the reaction systems and could be reused for several times without significant loss of catalytic activity.