Controllable Double Difluoromethylene Insertions into S−Cu Bonds: (Arylthio)tetrafluoroethylation of Aryl Iodides with TMSCF2Br.

A new method of constructing "ArSCF2CF2Cu" from ArSCu and TMSCF2Br (TMS=trimethylsilyl) has been developed. The cross‐coupling reactions of the obtained "ArSCF2CF2Cu" with diverse aryl iodides (Ar′I) provide an efficient access to Ar′CF2CF2SAr. Mechanistic studies demonstrate that the "ArSCF2CF2Cu" species were generated through controllable double difluoromethylene insertions into ArS−Cu bonds rather than the 1,2‐addition of ArSCu to tetrafluoroethylene. [ABSTRACT FROM AUTHOR]