Photoredox-catalyzed reaction of thianthrenium salts, sulfur dioxide and hydrazines

Abstract

A photoredox-catalyzed three-component reaction of thianthrenium salts, hydrazines and DABCO·(SO₂)₂ is accomplished, providing facile access to diverse arenesulfonohydrazides in moderate to good yields. Broad substrate scope generality is demonstrated, and excellent functional group compatibility is observed under mild reaction conditions. A radical pathway is proposed that is initiated from thianthrenium salts irradiated with visible light.