Acetylacetone–metal catalyst modified by pyridinium salt group applied to the NHPI-catalyzed oxidation of cholesteryl acetate

Abstract

Acetylacetone–metal catalysts modified by ionic compounds were used as co-catalysts in the NHPI-catalyzed oxidation of cholesteryl acetate by molecular oxygen under mild conditions. When cholesteryl acetate was oxidized at 30 °C for 10 h, a 79% isolated yield for 7-ketocholesteryl acetate was achieved. The dual role of pyridinium salt group onto the acetylacetone ligand, serving as an electron-withdrawing group and at the same time as a co-catalyst for the decomposition of alkyl hydroperoxide, was responsible for the high isolated yield.