Chiral Salen Mn(III) complex axial coordination immobilized on diamine modified ZSPP and their catalytic epoxidation of styrene

Abstract

Abstract Chiral Salen Mn(III) complex axial coordination immobilized on diamine modified zirconium oligo-styrenyl phosphonate hydrogen phosphate (ZSPP) were prepared by a covalent grafting method. All the supported heterogeneous chiral Salen Mn(III) complexes prepared were characterized by FT-IR, diffusion reflection UV–vis, AAS, N 2 volumetric adsorption, SEM, TEM and TG. These supported chiral catalysts showed a little lower chiral induction (ee, 72%) contrast of its homogeneous counterpart 1 (ee, 86%) for asymmetric epoxidation of styrene in presence of NMO as axial ligands with m -CPBA as an oxidant. The catalysts were easily recovered by filtration and could be reused at least five times with little loss of activity and enantioselectivity.