Chemodivergent Synthesis of Benzothiadiazin-3-one 1-Oxides and Benzisothiazol-3-ones via Visible Light-Promoted Intramolecular N–S Bond Formation

We reported a versatile protocol to chemodivergently construct significant heterocyclic scaffolds of benzothiadiazin-3-one 1-oxides and benzisothiazol-3-ones by visible light-promoted photocatalysis. This substrate-dependent chemoselective strategy enables N-(2-mercaptophenyl)-N'-substituted ureas through the N–S bond coupling/oxidation cascade to selectively produce benzothiadiazin-3-one 1-oxides; however, the transformation of 2-mercaptobenzamides only occurs via N–S bond coupling to access benzisothiazol-3-ones with moderate to good yields. This strategy features mild conditions, excellent chemoselectivity, and functional group compatibility, which has potential applications in organic and medicinal chemistry.