Photoinduced C(sp3)-H chlorination of amides with tetrabutyl ammonium chloride.

A new protocol was developed for the site-selective C(sp3)-H chlorination of amides with tetrabutyl ammonium chloride as the chlorinating agent. The reaction features a tandem sequence that involves a (diacetoxyiodo)benzene-mediated and chloride anion-involved N-H chlorination followed by photoinitiated chlorine atom transfer. A wide variety of carboxamides and sulfonamides were chlorinated at the δ-position by using this method.