Catalytic defluorinative [3 + 2] cycloaddition of trifluoromethylalkenes with alkynes via reduction of nickel(II) fluoride species.

Nickel-catalyzed [3 + 2] cycloaddition of 2-trifluoromethyl-1-alkenes with alkynes via domino C-F bond activation was achieved by sequential β-fluorine elimination. The nickel(ii) fluoride species formed in this reaction was reduced by a diboron compound, regenerating the catalytically active nickel(0) species.