Catalytic asymmetric epoxidation of unfunctionalized olefins using a series novel type of layered crystalline organic polymer-inorganic hybrid zinc phosphonate-phosphate immobilized aryldiamine modified chiral salen Mn(III) complex

In this report we demonstrate the suitability of layered crystalline organic polymer-inorganic hybrid material ZnPS-PVPA with different content of the organic group and different inorganic phosphate as catalyst supports for asymmetric catalysis. A series of the chiral salen Mn(III) complex immobilized onto ZnPS-PVPA modified by aryldiamine were synthesized and characterized by FT-IR, diffusion reflection UV-vis, AAS, N(2) volumetric adsorption, SEM, TEM, XRD and TG. The supported catalysts displayed superior catalytic activities in the asymmetric epoxidation of alpha-methylstyrene and indene with m-CPBA and NaIO(4) as oxidants, compared with the corresponding homogeneous catalyst (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 alpha-methylstyrene. These results revealed that the special structure of ZnPS-PVPA played vital impacts on the conversion and enantioselectivity. Furthermore, this novel type of catalyst can also be validly used in large-scale reactions with superior catalytic disposition being maintained at the same level, which possessed the potentiality for application in industry. (C) 2011 Elsevier B.V. All rights reserved.