Influence of the Transmetalating Agent in Difficult Coupling Reactions: Control in the Selectivity of C–F Bond Activation by Ni(0) Complexes in the Presence of AlMe3

Although Ni­(PEt3)4 does not react with di- or trifluoroarenes at room temperature, upon the addition of aluminum hydrocarbons such as AlMe3 an immediate reaction occurs, to give AlMe2F and Ni­(II) complexes from C–F bond activation and transmetalation. The influence of additional Lewis basic compounds, such as pyridine, on selectivity in these systems provides insight into how selectivity in a cross-coupling reaction is controlled by the transmetalating agent and how the oxidative addition and transmetalation steps are not necessarily distinct.