Visible-Light\nPhotoredox-Catalyzed Radical-Polar Crossover\n1,4-Hydrofluoromethylation of 1,3-Enynes

We report herein a visible-light\nphotoredox-catalyzed\n1,4-hydrofluoromethylation\nof terminal-alkene-derived 1,3-enynes with sodium fluoromethylsulfinate,\nproviding an effective protocol to access a diversity of di- and trisubstituted\nallenes under mild conditions. The synthetic utility of the present\nprotocol was demonstrated by a large-scale reaction as well as the\nsynthetic derivatization of the allene product.