Purely axial-chiral amine-base Bronsted-acid organocatalyst prototypes

Binaphthyl-based compounds are widely used as efficient organocatalysts in a plethora of asymmetric organic reactions. Typically, those asymmetric organocatalysts are center-chiral or combined axial-chiral and center-chiral. Here, we describe the efficient (up to 91% yield) synthesis of purely axial-chiral binaphthoazepines usable as precursors for the build up of a novel ligand library. In particular thiourea 11 resembles a known successful organocatalyst, but of a reduced molecular complexity.