Selective and mild oxidation of sulfides to sulfoxides or sulfones using H2O2 and Cp′Mo(CO)3Cl as catalysts

Dialkyl, aryl–alkyl, benzylic, and benzothiophenic sulfides are selectively oxidized to sulfoxides or sulfones, with stoichiometric amounts of H2O2 (aq) or TBHP, in the presence of complexes Cp′Mo(CO)3Cl, CpMoO2Cl and the mesoporous material MCM-41-2 as catalysts. The use of the thianthrene 5-oxide (SSO) probe shows that CpMo(CO)3Cl/H2O2 or TBHP are electrophilic oxidants (Xso ⩽ 15). The same conclusion is drawn from competition experiments with a mixture of p-ClC6H4SCH3 and C6H5SOCH3.