Synthesis of chiral 2,2′-dimethyl-1,1′-binaphthyl-8,8′-diamine and barriers of atropisomerization of the related binaphthyls

Chiral 2,2′-dimethyl-1,1′-binaphthyl-8,8′-diamine 3b was synthesized via a diastereomeric resolution and determination of the absolute configurations, and the barriers compared for atropisomerization amongst binaphthyl skeletons.