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.