Visible‐Light‐Driven Remote C−H Chlorination of Aliphatic Sulfonamides with Sodium Hypochlorite

The C(sp3)−H chlorination of aliphatic sulfonamides was realized by visible‐light photoredox catalysis with Ru(bpy)3Cl2 as photocatalsyt and NaOCl⋅5H2O crystals as the chlorinating agent. The reaction proceeds in a tandem pattern of N−H chlorination and Hofmann‐Löffler‐Freytag chlorination. A variety of differently substituted sulfonamides were chlorinated in this way in high yield. A radical‐chain mechanism is proposed for the reaction on the basis of experimental evidence. The C(sp3)−H chlorination of aliphatic sulfonamides was realized by visible light photoredox catalysis with Ru(bpy)3Cl2 as photocatalsyt and NaOCl⋅5H2O crystals as chlorinating agent. The reaction proceeds in a tandem pattern of N−H chlorination and Hofmann‐Löffler‐Freytag chlorination. A variety of differently substituted sulfonamides were chlorinated in this way in high yield. A radical chain mechanism is proposed for the reaction on the basis of experimental evidence.