Synthesis of novel chiral polyamide macrocycles containing pyridyl side-arms and their molecular recognition properties

Seven novel C₂-symmetrical macrocycles containing pyridyl units have been prepared by the cyclic condensation of homochiral diamide intermediates with 2,6-pyridinedicarbonyl dichloride under high dilution at room temperature. The molecular recognition of these homochiral macrocycles for amino acid derivatives has been characterized by various spectroscopic methods such as IR, FAB-MS, fluorescence and UV-vis. The macrocycle 11 exhibited significant chiral recognition towards the enantiomers of D- and L-alanine methyl ester hydrochlorides for which association constants have been determined. Molecular modeling was also used to simulate the interaction mode between the hosts and the guests.