Nickel-Catalyzed Allylic C(sp3)–F Bond Activation of Trifluoromethyl Groups via β-Fluorine Elimination: Synthesis of Difluoro-1,4-dienes

The nickel-catalyzed defluorinative coupling of 2-trifluoromethyl-1-alkenes and alkynes with the aid of Et 3 SiH provides 1,1-difluoro-1,4-dienes under mild reaction conditions. This reaction involves selective allylic C(sp 3 )–F bond activation via β-fluorine elimination from nickelacyclopentenes.