Chemoselective oxidation of sulfides to sulfoxides with urea hydrogen peroxide (UHP) catalyzed by non-, partially and fully β-brominated meso-tetraphenylporphyrinatomanganese(III) acetate

Selective oxidation of sulfides to sulfoxides with urea hydrogen peroxide in the presence of the manganese complex of non-, partially and fully brominated meso-tetraphenylporphyrin, (MnTPPBrx(OAc) (x = 0, 2, 4, 6 and 8)) is reported. Although, the maximum conversion was achieved in the case of MnTPPBr4(OAc), little difference was found between the catalytic activity of MnTPP(OAc), MnTPPBr2(OAc) and MnTPPBr4(OAc). MnTPPBr8(OAc) showed an unusually very low catalytic efficiency compared to the other manganese porphyrins. The presence of small amounts of acetic acid was shown to have significant effect on the total conversion and the oxidative stability of the catalyst.