Ni/Cu-Catalyzed Defluoroborylation of Fluoroarenes

Niwa and Hosoya et al. have reported the Ni(cod)₂/CuI-catalyzed transformation of fluoroarenes to arylboronic acid pinacol esters via C−F bond cleavage. In this report, the desired arylboronic ester products are successfully synthesized by mixing fluoroarenes, bis(pinacolato)diboron ((Bpin)₂), bis(1,5-cyclooctadiene)nickel(0) (Ni(cod)₂), tricyclohexylphosphine (PCy₃), CuI and CsF in toluene with heating at 80 °C. The ester products can be converted into various functionalized arenes through C−C, C−O, C−I, and C−N bond-forming transformations. This synthetic approach can be applied to the preparation of ¹⁸F-labeled probes for positron emission tomography (PET) imaging, and the isotope exchange of ¹⁹F-antilipemic fluvastatin derivative to the related ¹⁸F-derivative has also been achieved.