Bifunctional receptor triad for efficient recognition of mono- and dicarboxylic acids

An equimolar mixture of two conformers of Cinchona alkaloid based triads containing an aromatic diimide spacer is transformed with high efficiency into the syn conformer in the presence of dicarboxylic acids or into the anti conformer in the presence of monocarboxylic acids. The recognition process is readily observed by 1H NMR spectroscopy.