Chiral salen Mn(III) immobilized on sulfoalkyl modified ZSP-IPPA as an effective catalyst for asymmetric epoxidation of unfunctionalized olefins

Sulfoalkyl modified zirconium poly (styrene-isopropenyl phosphonate)-phosphate (ZPS-IPPA), with special structures of new type of organic–inorganic hybrid material were designed and synthesized for immobilization of the chiral salen Mn(III) Jacobsen’s homogenous catalyst by axial coordination. All the heterogeneous chiral salen Mn(III) catalysts with different linkage lengths obtained exhibited great catalytic activity and enantioselectivity in the asymmetric epoxidation of unfunctionalized olefins. The influence of the linkage lengths on the catalytic performance was investigated. What’s more, the catalysts were easily separated from the reaction systems and could be reused for several times without significant loss of catalytic activity.

Sulfoalkyl modified zirconium poly (styrene-isopropenyl phosphonate)-phosphate (ZPS-IPPA) were designed and synthesized for immobilization of the chiral homogenous salen Mn(III) catalyst by axial coordination. The linkage lengths of the sulfoalkyl modified ZPS-IPPA play an important role in ee values and yields of epoxidations. The heterogeneous catalysts are relatively stable and can be recycled nine times.Figure optionsDownload as PowerPoint slide