Chromium(VI) Oxide Catalyzed Oxidation of Sulfides to Sulfones with Periodic Acid

A highly efficient and selective oxidation of sulfides to sulfones with periodic acid catalyzed by CrO₃ is described. A variety of electron-rich and electron-deficient sulfides were oxidized to sulfones with 2 mol % CrO₃ in acetonitrile at room temperature in excellent yields. Sulfides with other readily oxidized functional groups were selectively oxidized to sulfones in high yields with 10 mol % CrO₃ in ethyl acetate/acetonitrile at −35 °C.