Qualitatively, it was found that the catalysts were more active across the series 1-B > 1-Al > 1-Ga. With the heavier group 13 catalysts requiring more forcing conditions and showing more limited scope than the lightest boron analogue. Reaction trends are consistent with a nucleophilic mechanism with regioselectivity determined by the most electrophilic position of the aromatic ring. In contrast to known Lewis acid catalysts based on group 13, these reactions are selective for sp 2 C-F over sp 3 C-F bonds with CF3 groups being tolerated under catalytic conditions. Less electron-deficient arenes, i.e. those with lower fluorine content, do not react under the optimised conditions.