Photoinduced copper catalyzed nitrogen-to-alkyl radical relay Sonogashira-type coupling of o -alkylbenzamides with alkynes.

This report describes a copper-catalyzed, photoinduced N -to-alkyl radical relay Sonogashira-type reactions at benzylic sites in o -alkylbenzamides with alkynes. The process employs an N -to-alkyl radical mechanism, initiated through the copper-catalyzed reductive generation of nitrogen radicals. Radical translocation is facilitated by a 1,5-hydrogen atom transfer (1,5-HAT), leading to the formation of translocated carbon radicals. These radicals are then subjected to copper-catalyzed alkynylation. The methodology exhibits broad sub-strate scope and applicability to the synthesis of complex natural products.