Enantioselective Atropisomeric Anilides Synthesis via Cu-Catalyzed Intramolecular Adjacent C–N Coupling

Catalytically asymmetric synthesis
of atropisomeric compounds is
an important research area in organic synthesis. However, in comparison
with C–C atropisomers, the atropisomers caused by the restricted
rotation of C–N single bonds have been given less attention
because of the limited methods for accessing these compounds. Herein
we report a Cu-catalyzed enantioselective intramolecular Ullmann-type
amination reaction for the synthesis of C–N atropisomers. The
C–N axial chirality was induced highly efficiently by the intramolecular
adjacent C–N cross-coupling. The readily prepared N,N′-(cyclohexane-1,2-diyl)­dipicolinamides showed high efficacy
and stereoinduction (up to 99% ee).