A high efficient large-scale asymmetric epoxidation of unfunctionalized olefins employing a novel type of chiral salen Mn(III) immobilized onto layered crystalline aryldiamine modified zinc poly(styrene-phenylvinylphosphonate)-phosphate

A series of chiral salen Mn(III) catalysts immobilized onto aryldiamine modified ZnPS-PVPA with different ratio of phosphonate/phosphate for asymmetric epoxidation were synthesized and characterized by FT-IR, diffusion reflection UV–Vis, AAS, N2 volumetric adsorption, SEM, TEM, XPS, XRD and TG. The supported catalysts displayed superior catalytic activities in the asymmetric epoxidation of α-methylstyrene and indene with m-CPBA and NaIO4 as oxidants. Moreover, the heterogeneous catalysts were relatively stable and could be recycled nine times in the asymmetric epoxidation of α-methylstyrene. Furthermore, this novel type of catalyst could 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.

Graphical abstractThe catalysts immobilized salen Mn(III) onto ZnPS-PVPA displayed superior catalytic ability both for experimental scale and for large-scale reactions.Figure optionsDownload full-size imageDownload high-quality image (118 K)Download as PowerPoint slideHighlights► Organic polymer–inorganic hybrid material layered crystalline ZnPS-PVPA was synthesized and characterized. ► The chiral salen Mn(III) was immobilized on aryldiamine modified ZnPS-PVPA. ► The heterogeneous catalysts displayed superior activity according to the homogeneous catalysts. ► The heterogeneous catalysts could be reused at least nine times without significant loss of activity. ► The catalysts could be used in large-scale reactions with superior catalytic disposition.