Recoverable MnIII(salen) supported on diamine modified zirconium poly(styrene-isopropenyl phosphonate)-phosphate as an efficient catalyst for epoxidation of unfunctionalized olefins

Chiral Mn III (salen) (Jacobsen’s catalyst) was axially immobilized onto a new type of organic polymer-inorganic hybrid material-zirconium poly(styrene-isopropenyl phosphonate)-phosphate(ZPS-IPPA) with different linkage lengths and evaluated as catalysts for the epoxidation of unfunctionalized olefins. The results demonstrated that the prepared catalysts exhibited moderate to good activity and enantioselectivity in the asymmetric epoxidation of unfunctionalized olefins. Furthermore, the immobilized catalysts were relatively stable and could be conveniently separated from the reaction system by simple precipitation in hexane. Moreover, higher enantioselectivity was obtained with catalyst 2c than that of homogeneous counterpart catalyzed even after eight times. The excellent recycling of the catalyst was attributed to its structure feature of ZPS-IPPA which is different from either pure polystyrene or pure zirconium phosphates.