URONIUM HYDROGEN SULFATE/UREA-HYDROGEN PEROXIDE AS A GREEN AND METAL-FREE CATALYTIC SYSTEM FOR THE EFFICIENT, CHEMO-, AND HOMOSELECTIVE OXIDATION OF SULFIDES TO SULFOXIDES

An efficient, chemoselective, and metal-free oxidation of sulfides is described using urea-hydrogen proxide (UHP) adduct as a stable, inexpensive, and easily handled reagent in the presence of uronium hydrogen sulfate (UHS). Both UHP and UHS release urea as an environmentally benign byproduct. The advantages of the described method are generality, chemoselectivity, short reaction time, low cost, high atom economy, and green chemistry protocols.