Electrophilic C–H Borylation and Related Reactions of B–H Boron Cations

Catalytic procedures are described for the amine-directed borylation of aliphatic and aromatic tertiary amine–boranes. Sequential double borylation is observed in cases where two or more C–H bonds are available that allow 5-center or 6-center intramolecular borylation. The HNTf<sub>2</sub>-catalyzed borylation of benzylamine–boranes provides a practical means for the synthesis of ortho-substituted arylboronic acid derivatives, suitable for Suzuki–Miyaura cross-coupling applications.