Photocatalytic Remote Alkenylation of Hydroxamides with Enamides: Synthesis of Trisubstituted Enamides via a Radical Pathway

Abstract

A photocatalytic radical-mediated strategy has been developed for the 1,5-hydrogen atom transfer (1,5-HAT)/alkenylation of hydroxamides with enamides, enabling the efficient synthesis of diverse, previously unreported trisubstituted enamides in moderate to good yields under mild conditions. This N-centered radical-triggered γ-C(sp3)-H alkenylation reaction demonstrates broad substrate scope, excellent functional group tolerance, and remarkable regio- and stereoselectivity. The proposed mechanism involves a sequential cascade of single-electron transfer (SET), 1,5-HAT, radical addition, oxidation, and deprotonation.