Tetra-(tetraalkylammonium)octamolybdate catalysts for selective oxidation of sulfides to sulfoxides with hydrogen peroxide

Tetra-(tetraalkylammonium)octamolybdate catalysts are successfully applied in the selective oxidation of various sulfides to sulfoxides with 30% aqueous hydrogen peroxide as oxidant under mild reaction conditions in 94-100% yield and 95-100% selectivity. The octamolybdate catalysts show high catalytic activity in a high ratio of substrate to catalyst (up to 10000:1) and are recyclable, with actively functional groups, including hydroxyl group and C[double bond, length as m-dash]C bonds, tolerated in the oxidation.