Microwave-assisted synthesis of novel amide based chiral tripodal receptors for recognition of cation and anion sensors

Abstract

Five novel amide based chiral tripodal receptors were synthesized under microwave irradiation by reacting nitrilotriacetic acid with chiral amino alcohols in a solvent-free medium with high yields (≥ 90%). The recognition affinities of these tripodal receptors were investigated towards anions and chiral organic ammonium cations using 1 H NMR titration method. The results show that receptor 1 displays more affinity against anions compared with other receptors and the tripodal receptor 4 demonstrated a significant enantiomeric selectivity towards the (R)-naphthylethylammonium perchlorate (ERF 54%).