Me3SiCF3/AgF/Cu—A new reagents combination for selective trifluoromethylation of various organic halides by trifluoromethylcopper, CuCF3

An alternative copper halide-free route to obtain highly reactive trifluoromethylcopper species has been developed via the reaction of silver fluoride and trimethyl(trifluoromethyl)silane followed by a redox transmetallation with elemental copper. The composition of the reactive intermediate was investigated by means of UV/Vis/NIR, ESR, 19F NMR spectroscopy and ESI mass spectrometry. “Trifluoromethylcopper” prepared by the oxidative transmetallation route exhibits excellent reactivity and selectivity in substitutions of iodine or bromine bond to aromatic or heterocyclic compounds for trifluoromethyl groups without any additional catalyst.

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► Convenient halide-free synthesis of trifluoromethyl silver–copper couples.
► Involvement of CuI, CuII and CuIII species.
► Efficient reagents for the introduction of trifluoromethyl groups.
► Effective C–C couplings with aromatics and activated sp3 carbons.