Synthesis of new C2 symmetric chiral tetraamide compounds and usage of some amine and amino acide esters in enantiomeric recognition

UV-Vis Spectroscopy is a widely used method for calculating binding constants (Ka). Using the Benesi-Hildebrand equation, the binding constants of the complexes formed between the receptor (host) and the guest molecules are calculated from the data obtained from UV-Visible titration experiments. In this work, two novel C2 symmetrical chiral tetraamide compounds derived from (S)-isoleucine were synthesised and their enantiomeric recognition abilities towards enantiomers of some amino acid esters and l-arylethylamins were examined by UV-titration method. The prepared amide compounds were characterized by elemental analysis, infrared spectroscopy (IR), 1H nuclear magnetic resonance (NMR) and 13C nuclear magnetic resonance (NMR). These receptor compounds exhibited strong complexation (with Ka up to 5787.23 M-1) and very good enantioselectivity (up to KaS/KaR = 13.98).