The synthesis of optically active N-C axially chiral tetrahydroquinoline and its response to an acid-accelerated molecular rotor

Optically active atropisomeric N-(2,5-di-tert-butylphenyl)-1,2,3,4-tetrahydroquinoline with an N–C chiral axis was prepared via a catalytic enantioselective reaction. The addition of methane sulfonic acid to this axially chiral quinoline dramatically lowered the barrier to rotation around the chiral axis.