Selectivity in Oxidation of Sulfides with Hydrogen Peroxide by [π-C5H5N+(CH2)15CH3]3PM12O403− and [π-C5H5N+(CH2)15CH3]3{PO4[M(O)(O2)2]4}3− (M = Mo or W)

Dramatical difference in selectivity was observed in the hydrogen peroxide oxidation of sulfides by [π-C5H5N+(CH2)15CH3]3PW12O403− (CWP) and [π-C5H5N+(CH2)15CH3]3{PO4[W(O)(O2)2]4}3− (PCWP) under the two-phase system using chloroform as the solvent. The oxidation of sulfides with 35% H2O2 by CWP afforded the corresponding sulfoxides in high selectivity (93–99%), while the same oxidation by PCWP gave sulfones exclusively.