Studies on the Synthesis of a Chiral Salen Mn (III) Complex Immobilised onto Zirconium Aminophosphonates and Catalytic Asymmetric Epoxidation of α–methylstyrene

Abstract

A chiral salen Mn (III) complex has been immobilised onto zirconium aminophosphonates by axial coordination with different linkage arm lengths (CH2) n ( n = 2–6), to give a series of heterogeneous catalysts. The catalysts exhibited good to excellent catalytic efficiency in the asymmetric epoxidation of α–methylstyrene. One heterogeneous catalyst, with n = 6, gave higher catalytic properties than the original chiral salen Mn (III) complex in the NaClO/PPNO system. It can be easily recovered and reused several times without significant loss of activity.