A surfactant-like ionic liquid with permanganate dissolved as a highly selective epoxidation system

•Permanganate in ionic liquid medium as a new catalytic epoxidation system•A ligand-free epoxidation system for a variety of aliphatic terminal alkenes•The catalytic system achieving excellent selectivity and yield for epoxides•The results reveal an unusual oxidation behavior of permanganate in ionic liquid.

A ligand-free catalytic epoxidation system using permanganate in a surfactant-like ionic liquid (IL) medium was developed. The results indicate that the IL takes crucial effects in the epoxide selectivity. The loading of permanganate is also found critical in preventing over-oxidation of epoxides. The system with 0.3 mol% permanganate and 3.5-equivalent CH3CO3H is able to achieve excellent yields and selectivity of epoxides. The study of epoxidation with KMnO4 in IL medium reveals an unusual oxidation behavior of permanganate not found in traditional solvents.

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