Enantioselective recognition of amino acids by chiral peptido-calix[4]arenes and thiacalix[4]arenes

In order to prepare new molecular hosts able to discriminate enantiomers of amino-acid derivatives, we have synthesized chiral thiacalix[4]arenes. Extensive studies using NMR and mass spectrometry techniques allow us to determine the major supramolecular interactions involved in the recognition process. Moreover, a titration study enables us to determine the binding constant between these new hosts and a series of amino-acid derivatives. Finally, we have also demonstrated that these calixarenes are able to discriminate enantiomers of amino-acid guests.