RhIII‐Catalyzed Directed C−H Bromination and Iodination to Synthesize Atropisomeric Biaryls

The [RhIIICp*]-catalyzed directed C−H bromination and iodination reactions of 2-aryl isoquinolines/pyridines are highly efficient and afford atropisomeric biaryl compounds (Cp*=1,2,3,4,5-pentamethylcyclopenta-2,4-dienyl) in good yields. Among several reported C−H bond halogenation methods, the combination of [RhIIICp*Cl2]2/AgSbF6, N-halosuccinimide, and pivalic acid in 1,2-dichloroethane is found to be the only effective catalytic system to provide atropisomeric 2′-halogenated 2-aryl isoquinolines/pyridines.