Copper-Mediated Aromatic 1,1-Difluoroethylation with (1,1-Difluoroethyl)trimethylsilane (TMSCF2 CH3 ).

A new method for the formation of 1,1-difluoroethyl copper species ("CuCF2 CH3 ") with 1,1-difluoroethylsilane (TMSCF2 CH3 ) has been developed. The "CuCF2 CH3 " species can be applied to the efficient 1,1-difluoroethylation of diaryliodonium salts under mild conditions, affording (1,1-difluoroethyl)arenes in good to excellent yields. This convenient procedure tolerates a wide range of functional groups and thus serves as a practical synthetic tool for the introduction of CF2 CH3 group(s) into complex molecules.