3H‐Phenothiazin‐3‐one: A Photocatalyst for the Aerobic Photochemical Oxidation of Sulfides to Sulfoxides

Abstract In this study, 3 H ‐phenothiazin‐3‐one is identified as a photocatalyst for the photochemical oxidation of sulfides to sulfoxides. This photocatalytic method uses a low catalyst loading (0.05 mol%), molecular oxygen as the sole oxidant, and a blue LED lamp as the irradiation source. It can be applied to the oxidation of both alkyl‐aryl and alkyl‐alkyl sulfides. Moreover, the method is also applicable in the synthesis of the known pharmaceutically active compounds Modafinil and Sulforaphane.