Hydrogen Bond Directed ortho-Selective C-H Borylation of Secondary Aromatic Amides

摘要

Reported is an iridium catalyst for ortho-selective C-H borylation of challenging secondary aromatic amide substrates, and the regioselectivity is controlled by hydrogen-bond interactions. The BAIPy-Ir catalyst forms three hydrogen bonds with the substrate during the crucial activation step, and allows ortho-C-H borylation with high selectivity. The catalyst displays unprecedented ortho selectivities for a wide variety of substrates that differ in electronic and steric properties, and the catalyst tolerates various functional groups. The regioselective C-H borylation catalyst is readily accessible and converts substrates on gram scale with high selectivity and conversion.