Thioxanthone-TfOH complex (9-HTXTF) photoredox enabled reduction of sulfoxides

This study presents a photoredox-mediated reduction of sulfoxides, employing 9-HTXTF as photocatalyst and THF as an external reductant. Scope investigation revealed that diverse substrates, including those with electron-donating and electron-withdrawing groups, could be transformed into corresponding sulfides. Mechanistic insights suggest a cascade of events initiated by the excited state of 9-HTXTF, involving multiple single-electron reduction steps and proton transfers. This approach enriches the toolkit for sulfoxide reduction under photoredox catalysis as sustainable synthetic strategies.