Copper Catalyzed Defluoroarylation of gem-Difluoroallenes to Allenyl Monofluorides with Aryl Boronic Esters

Few studies have been performed on allenyl monofluorides, especially on aryl-substituted frames, due to concerns about their stability. Here we report a copper-catalyzed regioselective synthesis of such structures with inexpensive and accessible aryl boronic esters under mild conditions. Arylated allenyl monofluorides were stable enough to be isolated and easily converted to various other fluorine-containing blueprints. Preliminary asymmetric attempts demonstrate that the reaction could proceed via a selective β-fluorine elimination process.