OXIDATIONS OF BENZYL AND PHENETHYL PHENYL SULFIDES - IMPLICATIONS FORTHE MECHANISM OF THE MICROSOMAL AND BIOMIMETIC OXIDATION OF SULFIDES

The study of the oxidation of 4-methoxyphenethyl phenyl sulfide and 3, 4-dimethoxyphenethyl phenyl sulfide with potassium 12-tungstocobalt(II I)ate [Co(III)W] suggests that in the radical cations of 3,4,5-(MeO)(3 )PhCH2SPh (4) and 2,4,6(MeO)(3)PhCH2SPh (5) the positive charge is not localized on the sulfur atom, but in the benzylic aromatic ring. Neve rtheless, in the biomimetic and microsomal oxidation of 4 and 5 the pr oducts observed are exclusively sulfoxides and sulfones, which appears in contrast with a mechanism involving the formation of an intermedia te sulfide radical cation followed by a fast oxygen rebound. A direct oxygen transfer mechanism seems most likely. (C) 1997 Elsevier Science Ltd.