Ion-Pair-Directed meta-Selective C-H Borylation of Aromatic Quaternary Ammonium Salts

We recently reported the use of ion pairing as a key noncovalent interaction to control regioselectivity in the iridium-catalyzed CH borylation of aromatic quaternary ammonium salts. Two classes of substrates, benzylamine- and aniline-derived ammonium salts were selectively borylated at the meta position by employing a newly developed anionic ligand for the iridium. It was proposed that the ligand interacts with the cationic substrate via an ion-pairing interaction, positioning the substrate in the optimal orientation for selective activation of the meta C-H bond. 1 Introduction 2 Ion-Pair-Directed meta C-H Borylation 3 Control Experiments 4 Unexpected Selectivity with dtbpy in Cyclohexane 5 Conclusions