Tantalum(V) or niobium(V) catalyzed oxidation of sulfides with 30% hydrogen peroxide

Tantalum(V) and niobium(V) are effective catalysts for the oxidation of sulfides with 30% hydrogen peroxide. The reaction of sulfides with 30% hydrogen peroxide catalyzed by tantalum(V) chloride or niobium(V) chloride in acetonitrile, i-propanol or t-butanol selectively provided the corresponding sulfoxides in high yields. The corresponding sulfones are efficiently obtained from the reaction of sulfides with 30% hydrogen peroxide in methanol catalyzed by tantalum(V) or niobium(V).