Biphasic oxidation of sulfides with hydrogen peroxide, catalyzed by partially water-soluble cationic salphen complex

Sulfides were selectively oxidized to the corresponding sulfoxides or sulfones in good yields by hydrogen peroxide using a partially water-soluble cationic manganese(III)–salphen complex as an efficient phase transfer catalyst for chemoselective oxidation, under mild conditions. The experimental data show that the cationic salt is more active than its neutral form. The acceleration of the reaction rate is attributed to the phase transfer capability of the built-in phenazinium salt of the Mn(III)–salphen catalyst.