Copper-Mediated Oxidative Chloro- and Bromodifluoromethylation of Phenols

The first oxidative chloro- and bromodifluoromethylation of phenols with (CH 3 ) 3 SiCF 2 X and CuX (X = Cl or Br) in the presence of Selectfluor under mild reaction conditions was developed. This protocol provided a practical and efficient method for the synthesis of a diverse range of biologically valuable and synthetically challenging chloro- and bromodifluoromethyl aryl ethers. Preliminary mechanistic studies suggest that this reaction proceeded through a difluorocarbene-involved oxidative coupling process.