Visible-light-induced defluorinative allylation of difluoromethyl ketones using alkylamines as bifunctional agents

A visible-light-induced alkylamine-facilitated reductive defluoroallylation of difluoromethyl ketones with allylic chlorides is reported, enabling efficient access to & alpha;-fluoro alkenylketones with high efficiency under catalyst-free and mild conditions. In this reaction, alkyl amines function as bifunctional agents: an electron donor for forming an electron donor-acceptor complex to trigger the selective C-F bond cleavage of CF2H-ketones and a halogen-atom transfer agent for activating the C-Cl bond of allylic chlorides. This protocol exhibits a broad substrate scope of CF2H-ketones and allylic halides. Synthetic derivatizations of the resulting & alpha;-fluoro alkenylketones and preliminary mechanistic studies have been presented.