Highly efficient utilization of H2O2 for oxygenation of organic sulfides catalyzed by [γ-SiW10O34(H2O)2]4−

Remarkable efficiency of hydrogen peroxide utilization is reported for oxygenation of four organic sulfides catalyzed by a divacant lacunary silicotungstate, (Bu4N)4[γ-SiW10O34(H2O)2] (1), under mild conditions. The addition of imidazole, phosphate, or carboxylates significantly enhances the rate of organic sulfide oxygenation. Most notably, use of 1 and imidazole, both at 1% molar concentration, resulted in the quantitative conversion of phenylsulfide to sulfoxide with 1 equiv of H2O2 in 3 h, and to sulfone with 2 equiv of H2O2 in 6 h.