Metal-free chemoselective oxidation of sulfides to sulfoxides by hydrogen peroxide catalyzed by in situ generated dodecyl hydrogen sulfate in the absence of organic co-solvents

The mild oxidation of sulfides to sulfoxides with an aqueous solution of H2O2 (35%) catalyzed by in situ generated dodecyl hydrogen sulfate as Bronsted acid surfactant in the absence of any organic cosolvents and under metal-free conditions is described. The method shows high chemoselectivity and the process is highly green for solid sulfoxides which crystallize out immediately after their formation from the reaction mixture. Liquid sulfoxides can be isolated under high vacuum by bulb-to-bulb distillation or by extraction with Et2O or EtOAc. Yields of the products are excellent.