Highly efficient epoxidation of olefins with hydrogen peroxide oxidant using modified silver polyoxometalate catalysts

摘要

The catalytic epoxidation of olefins is an important reaction in chemical industry since epoxides are versatile and important intermediates in the synthesis of fine chemicals and pharmaceuticals. The current epoxidation procedures often use stoichiometric organic and sometimes toxic inorganic oxidants that are less favourable from an environmental and economical point of view. In contrast to such processes, catalytic epoxidation processes employing H2O2oxidant are preferred for green processing. Herein is reported a highly efficient green process for the epoxidation of olefins using H2O2oxidant and modified silver polyoxometalate catalysts at 65°C. The preparation and activity of the catalysts are described. The method enjoys 90% conversion and ≥99% selectivity to the epoxide for a variety of cyclic and linear olefins including terminal ones. The catalysts are easily recovered by filtration and are reusable several times.