Atypical Outcome of the Giese Reaction with Halogenated Enones

An atypical pathway in the Giese reaction is being reported. Photoredox-mediated 1,4-addition of α-amino radicals onto an α'-fluorinated enone was found to proceed with a loss of fluoride and retention of the acceptor C═C bond. Experimental observations and computational analysis are consistent with the initially formed fluorinated α-carbonyl radical intermediate undergoing rapid deprotonation rather than the typically observed one-electron reduction. This underexplored reactivity may aid the development of an oxidative Giese reaction.