meta-Selective C-H Borylation of Benzamides and Pyridines by an Iridium-Lewis Acid Bifunctional Catalyst

Abstract

We report herein the iridium-catalyzed meta-selective C-H borylation of benzamides by using a newly designed 2,2'-bipyridine (bpy) ligand bearing an alkylaluminum biphenoxide moiety. We also demonstrate the iridium-catalyzed C3-selective C-H borylation of pyridine with a 1,10-phenanthroline (Phen) ligand bearing an alkylborane moiety. It is proposed that the Lewis acid-base interaction between the Lewis acid moiety and the aminocarbonyl group or the sp²-hybridized nitrogen atom accelerates the reaction and controls the site-selectivity.