The development of structurally simple chiral hosts for the enantioselective recognition of α-amino acids by an unified approach still represents an open challenge in the field of molecular recognition and sensing. Successful chiral hosts developed hitherto1 depend on two different binding motifs for the recognition of the amine moiety and the carboxylate moiety of α-amino acids.
Herein, we report the design and synthesis of a simple homoditopic binaphthyl based chiral receptor 1 for the chiral discrimination of α-amino acids. The chiral receptor 1 utilizes o-(carboxamido)trifluoroacetophenone2,3 motifs for both carboxylate and amine recognition. The chiral discrimination of various α-amino acids by receptor 1 can be conveniently monitored by proton coupled 19F NMR of the trifluormethyl groups of the receptor 1-amino acid adducts. The unique 1:1 binding mode was further confirmed by Isothermal Titration Calorimetry.
1) Park, H.; Kim, K.M.; Lee, A.; Ham, S.; Nam, W.; Chin, J. J. Am. Chem. Soc. 2007, 129, 1518.
2) Kim, Y.K.; Lee, Y.-H.; Lee, H.-Y.; Kim, M.K.; Cha, G. S.; Ahn, K. H. Org. Lett. 2003, 5, 4003.
3) Ryu, D.; Park, E.; Kim, D.-S.; Ham, S.; Yan, S.; Lee, J.S.; Chang, B.-Y.; Ahn, K. H. J. Am. Chem. Soc. 2008, 130, 2394.