Triarylboranes Bearing ( <i>ortho</i> -Carboran-1-yl)aryl Groups for Catalytic Hydrogenation with Pure or Crude H ₂

Structural diversification of triarylboranes with unexplored substituents can expand their applications in organic synthesis. We synthesized triarylboranes that bear 2,6-F₂-4-(<i>o</i>-carboran-1-yl)phenyl (Ar) groups and evaluated their Lewis acidity and catalytic activity. B(2,6-Cl₂C₆H₃)Ar₂ exhibited high activity in the hydrogenation of <i>N</i>-heteroaromatics using pure (TON = up to 3960) and crude H₂ (TON = up to 2400). This borane also catalyzes the dehydrogenation of tetrahydroquinoline and the reductive alkylation of aliphatic amino-acid esters with H₂, demonstrating the first catalytic applications of carboranyl-substituted triarylboranes in diverse molecular transformations.