Novel sucrose-based macrocyclic receptors for enantioselective recognition of chiral ammonium cations

A new synthetic route to macrocyclic sucrose-based receptors with different substituents at the ring nitrogen atom is described. Very good enantioselectivity toward phenylethylammonium chloride was observed a much stronger complex with the cation of the (S)-amine was formed] although the K_a values were low. Much higher K_a (1.4 × 10⁴ M^?1 in CDCl₃/CD₃OD) values of the complexes with aminoacid derivatives (especially valine) were found although this time the enantioselectivities were moderate.