Pentafluoroethylation of Arenediazonium Tetrafluoroborates Using On‐Site Generated Tetrafluoroethylene

Summary of main observation and conclusion Copper‐mediated pentafluoroethylation of arenediazonium tetrafluoroborates with tetrafluoroethylene (TFE) on‐site generated from TMSCF3 has been developed as a new method to prepare pentafluoroethyl arenes. The active pentafluoroethylation reagent “CuC2F5” is pre‐generated from CuSCN, TFE and CsF, and its generation and further reaction are strongly solvent‐dependent. This pentafluoroethylation reaction represents the first example of Sandmeyer‐type pentafluoroethylation, which exhibits good functional group tolerance and potential applications for the synthesis of complicated bioactive compounds. Copper‐mediated pentafluoroethylation of arenediazonium tetrafluoroborates with tetrafluoroethylene (on‐site generated from TMSCF3) has been developed as a new method to prepare pentafluoroethyl arenes.