Activation of Bis(trimethylsilyl) Peroxide and tert ‐Butyl Hydroperoxide with Oxo and Peroxo Complexes of Vanadium, Molybdenum, and Tungsten for the Sulfoxidation of Thianthrene 5‐Oxide

Bis(trimethylsilyl) peroxide (BTSP) and tert ‐butyl hydroperoxide ( t BuOOH) were activated by various oxo and peroxo complexes of molybdenum, tungsten, and vanadium as catalysts for the sulfoxidation of thianthrene 5‐oxide (SSO). A screening of a number of phosphane oxide and amine oxide ligands revealed that BTSP was most efficiently activated by the [MoO 5 (OP t Bu 3 )] complex. The best results for t BuOOH as oxygen source were achieved with the vanadates [VO(OR) 3 ] (R = t Bu, i Pr). Comparative selectivity and rate data for the stoichiometric and catalytic sulfoxidations of SSO mediated by the MoO 5 L complex (L = OP t Bu 3 , OP n Oct 3 , ON n Bu 3 , ON n Oct 3 ) suggest that the bisperoxo metal complex is the active oxygen transfer species.