Rh-III-Catalyzed Directed C-H Bromination and Iodination to Synthesize Atropisomeric Biaryls

Abstract

The [(RhCp)-Cp-III*]-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 [(RhCp)-Cp-III*Cl-2](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