Copper-Mediated Aromatic 1,1-Difluoroethylation with (1,1-Difluoroethyl)trimethylsilane (TMSCF₂CH₃)

A new method for the formation of 1,1-difluoroethyl copper species (“CuCF₂CH₃”) with 1,1-difluoroethylsilane (TMSCF₂CH₃) has been developed. The “CuCF₂CH₃” 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 CF₂CH₃ group(s) into complex molecules.