Copper-Catalyzed ipso-Borylation of Fluoroarenes

ipso-Borylation of fluoroarenes has been achieved using an air-stable copper complex as a catalyst. Mechanistic studies suggest that the reaction proceeds via an S_RN1 mechanism involving a single-electron-transfer (SET) process and not via the typical S_NAr mechanism. This method differs from the previously reported nickel/copper-cocatalyzed system in terms of scope of the substrate and has exhibited good scalability. Double and triple ipso-borylations of several di- and trifluoroarenes have been also achieved efficiently, enhancing the synthetic utility of this method.