Layered crystalline chiral salen Mn(III) complexes immobilized on organic polymer–inorganic hybrid zinc phosphonate-phosphate as efficient and reusable catalysts for the unfunctionalized olefin epoxidation

• The chiral salen Mn(III) is immobilized on alkyldiamines modified ZnPS-PVPA.
• The heterogeneous catalysts display 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.

Chiral Mn(III) salen complexes grafted on ZnPS-PVPA (zinc poly(styrene-phenylvinyl-phosphonate)-phosphate) upon alkyldiamines through a facile method are evaluated by the asymmetric epoxidation of unfunctionalized olefins. Superior catalytic performances are obtained (conv%, up to > 99; ee%, up to > 99) whenever with m-CPBA or NaClO or NaIO4 as the oxidant. The additives such as NMO, PPNO as well as imidazole play different roles in the corresponding oxidation system. In addition, the supported catalysts could be reused nine times with the retention of their efficiency. These results highlight the potentiality of ZnPS-PVPA as the support for immobilizing chiral salen Mn(III) to be employed in oxidation reactions.

The catalysts that alkyldiamines modified ZnPS-PVPA are used for the immobilization of chiral salen Mn(III) display superior catalytic ability either for the experimental scale reactions or for the large-scale reactions.Figure optionsDownload as PowerPoint slide