Oxygen Transfer Processes to Sulfides and Sulfoxides Mediated by Cetylpyridinium Tetrakis (Diperoxomolybdo) Phosphate

Oxidation of some aryl methyl sulfides and aryl methyl sulfoxides with hydrogen peroxide, mediated by cetylpyridinium tetrakis(diperoxomolybdo)phosphate (PCMP), was performed in chloroform/ethanol. In addition, the stoichiometric oxidation of sulfoxides to sulfones by PCMP was carried out in chloroform. Second-order rate laws, first order with respect to substrate and to PCMP, were observed in both catalytic and stoichiometric processes. Kinetic data seem to indicate that sulfides are oxidized by a bimolecular process which involves a nucleophilic attack of the substrate on the peroxidic oxygen. On the other hand, the possibility of radical incursion is suggested in the oxidation of sulfoxides. © 1991.