Supramolecular enantiomeric and structural differentiation of amino acid derivatives with achiral pillar[5]arene homologs.

Complexation of achiral pillar[5]arenes with chiral amines induced strong circular dichroism (CD) signals. The CD responses differed drastically depending on the nature of the amino acid guest, and they significantly varied and part of them even inverted, upon increasing the length of the alkyl chains of the pillar[5]arenes guests. Accordingly, this tactic allowed for the unprecedented simultaneous enantiomeric and structural differentiation of α-amino esters with homologous molecular hosts.