Stoichiometric and Catalytic Insights into the Lithium Nickelate Me-diated C–F Bond Alkynylation of Fluoroarenes

Low-valent nickelates have recently been shown to be key intermediates that facilitate challenging cross-coupling reac-tions under mild conditions. Expanding the synthetic poten-tial of these heterobimetallic complexes, herein we report the ability of tri-lithium nickelate Li3(TMEDA)3Ni(C≡C–Ph)3 to promote the stoichiometric C–F activation of aryl fluorides furnishing novel mixed Li/Ni(0) or Li/Ni(II) species depend-ing on the substrate and conditions employed. These stoichi-ometric insights can be upgraded to catalytic regimes to enable the atom-efficient alkynylation of aryl fluorides and polyfluoroarenes with lithium acetylides and Ni(COD)2 as pre-catalyst, and operates without the need for external lig-ands, Cu co-catalysts or additives.