A Key Intermediate in Copper-Mediated Arene Trifluoromethylation, [nBu4 N][Cu(Ar)(CF3 )3 ]: Synthesis, Characterization, and C(sp2 )-CF3 Reductive Elimination.

The synthesis, characterization, and C(sp2 )-CF3 reductive elimination of stable aryl[tris(trifluoromethyl)]cuprate(III) complexes [nBu4 N][Cu(Ar)(CF3 )3 ] are described. Mechanistic investigations, including kinetic studies, studies of the effect of temperature, solvent, and the para substituent of the aryl group, as well as DFT calculations, suggest that the C(sp2 )-CF3 reductive elimination proceeds through a concerted carbon-carbon bond-forming pathway.