Enantiodifferentiating Photodimerization of a 2,6‐Disubstituted Anthracene Assisted by Supramolecular Double‐Helix Formation with Chiral Amines

Abstract

Abstract A novel 2,6‐anthrylene‐linked bis( m ‐terphenylcarboxylic acid) strand ( 1 ) self‐associates into a racemic double‐helix. In the presence of chiral mono‐ and diamines, either a right‐ or left‐handed double‐helix was predominantly induced by chiral amines sandwiched between the carboxylic acid strands with accompanying stacking of the two prochiral anthracene linker units in an enantiotopic face‐selective way, as revealed by circular dichroism and NMR spectral analyses. The photoirradiation of the optically active double helices complexed with chiral amines proceeded in a diastereo‐ ( anti or syn ) and enantiodifferentiating way to afford the chiral anti ‐photodimer with up to 98 % enantiomeric excess when ( R )‐phenylethylamine was used as a chiral double‐helix inducer. The resulting optically active anti ‐photodimer can recognize the chirality of amines and diastereoselectively complex with chiral amines.