Photoinduced Site-Selective C(sp)-H Chlorination of Aliphatic Amides.

Herein, we report a new photochemical method for C(sp)-H chlorination of amides which employs -butyl hypochlorite as the chlorinating agent and a household compact fluorescent lamp as the light source. The reaction proceeds via N-heterocyclic carbene SIPr·HCl-promoted N-H chlorination and subsequent photoinduced Hofmann-Löffler-Freytag chlorine atom transfer. The latter process is facilitated by (diacetoxyiodo)benzene. This protocol exhibits a broad scope and is suitable for site-selective chlorination of methyl hydrogen as well as methylene and methine hydrogen.