Visible-light-promoted aerobic oxidation of sulfides and sulfoxides in ketone solvents

Simple and readily available ketones have been identified to promote the visible-light-promoted aerobic oxidation of sulfides and sulfoxides to sulfones. We report a simple and environmental-friendly oxidation protocol of sulfides to sulfones. Various sulfides were efficiently oxidized into sulfones with O2 as sustainable terminate oxidant, readily available thioxanthone as the photocatalyst and 3-pentanone (DEK) as the solvent. The protocol tolerates diverse functional groups, including halogens, ketone, ester, cyano, heterocycle and even cyclopropyl groups. The detection of the aerobic oxidation reaction in DEK by GC and HRMS disclosed that the key active intermediates were generated.