Kinetic and mechanism of the aqueous selective oxidation of sulfides to sulfoxides: insight into the cytochrome P450-like oxidative metabolic process

Abstract

The selective oxidation of sulfides with hydrogen peroxide to give sulfoxides was carried out in aqueous solution by water-soluble manganese porphyrin as mimics of cytochrome P450-like catalyst. Different factors that influencing the selective oxidation of sulfides, for example, catalyst, amount of catalyst, solvent and reaction temperature were investigated. MnTE4PyP (meso-tetrakis(N-ethylpyridinium-4-yl) manganese porphyrin) was efficient and selective catalyst for oxidation of various sulfides. The reaction showed first-order dependence in both [sulfide] and [ H 2 O 2], and a fractional order respect to catalyst. Oxygen atom transfer mechanism involves high-valence intermediate was proposed, which was supported by kinetic orders and spectrophotometric evidences.