Harnessing applied potential to oxidation in water

Abstract

Oxidation is one of the most important types of transformation in chemistry, and practical mild oxidation without added reagents or solvents has been a long-standing challenge. We have developed a highly practical solvent-free (biphasic) electrochemically driven oxidation system for the selective conversion of sulfides to the corresponding sulfoxides, and alkenes to the corresponding epoxides, in a very simple reactor system. Excellent yields are obtained for a variety of substrates, and neither over-oxidation to sulfone nor formation of diol by-products from alkene oxidation is observed. This simple system has excellent potential for scale-up, requires no storing or transport of stoichiometric oxidants, no heavy metals, and can be carried out with just water, sodium carbonate, hydrochloric acid, and an applied potential in a single cell. The electrolyte solution can be recycled and reused with no loss in activity.