Retracted Article: A series of novel types of immobilized chiral salen Mn(iii) on different organic polymer-inorganic hybrid crystalline zinc phosphonate-phosphate act as catalysts for asymmetric epoxidation of unfunctionalized olefins

Abstract

A novel type of layered crystalline organic polymer-inorganic hybrid material, zinc poly(styrene-phenylvinylphosphonate)-phosphate (ZnPS-PVPA) was synthesized and an array of new heterogeneous catalysts were gained by grafting chiral salen Mn(III) onto the ZnPS-PVPA, and characterized by FT-IR, diffusion reflection UV-vis, AAS, N₂ volumetric adsorption, SEM, TEM, XPS, XRD and TG. The immobilized chiral salen Mn(III) catalysts exhibited higher chiral induction in the asymmetric epoxidation of α-methylstyrene and indene with m-CPBA and NaIO₄ as oxidants than the corresponding homogeneous catalyst did (ee, >99% vs. 54% and >99% vs. 65%). And the heterogeneous catalysts are relatively stable and can be recycled nine times in the asymmetric epoxidation of α-methylstyrene. Furthermore, this novel type of catalyst can also be efficiently used in large-scale reactions with superior catalytic ability being maintained at the same level, which possessed the potentiality for application in industry.