Metal‐Free Divergent Photocatalytic Cascade [4+2] Addition‐Defluorinative Annulation of gem‐Difluoroalkenes with Terminal Alkynes

Abstract A mild, metal‐free protocol for cascade [4+2] addition‐defluorinative annulation of gem ‐difluoroalkenes with alkynes was realized via photoredox catalysis. This method was feasible for a wide range of terminal alkynes, affording the 1,3‐cyclohexadiene derivatives or fluoro‐substituted arenes in moderate to good yields, respectively. The merit of this strategy was demonstrated by the late‐stage functionalization of pharmaceuticals and the synthesis of high‐value‐added complex molecules.