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

Abstract

We recently reported the use of ion pairing as a key noncovalent interaction to control regioselectivity in the iridium-catalyzed C–H 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

Key words

ion pairing - iridium - borylation - meta selectivity - C–H activation

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