An Acceleration Effect of a Carbene Catalyst Toward C–F Bond Cleavage at a Gallium Center

An acceleration effect of a carbene catalyst toward oxidative addition (OA) of a C–F bond in hexafluorobenzene to gallylenes is reported. It was shown that the catalytic amount of IMe 4 (1,3,4,5‐tetramethylimidazol‐2‐ylidene) enables the OA of C–F bond to a neutral Ga(I) center of two‐coordinate gallylenes having NacNac (1,3‐diketiminate) or Boxm [bis(oxazolinyl)methanide] ligand under significantly milder conditions than those previously reported. Tri‐coordinate Ga(I)–IMe 4 adducts were successfully isolated as an intermediate and structurally characterized. Compared with the reaction of NacNac‐gallylene, IMe 4 is more efficient in the catalytic reaction of Boxm‐gallylene, which may relate to Boxm‐gallylene‐IMe 4 adduct immune to deprotonation of the ligand. DFT calculations supported that the coordination of IMe 4 to the Ga(I) center significantly raises the HOMO energy of the gallylene to increase the nucleophilicity at the Ga center.