Synthesis of meso-2,2’-bipyridyl-substituted calix[4]arenes and their response to metal cations

A convenient synthetic approach to meso -substituted with 2,2’-bipyridine and 1-(pyridin-2-yl)isoquinoline residues calix[4]arenes is reported. This approach involves the reaction of generated in situ 2-lithio-calix[4]arene with 1,2,4-triazine precursor with the following aromatization of the obtained adduct, and the aza -Diels-Alder reaction of the 1,2,4-triazinyl-substituted calix[4]arene with 2,5-norbornadien or in-situ generated 1,2-dehydrobenzene. The UV/fluorescence response of thus obtained meso -pyridyl-substituted calix[4]arenes to metal cations is studied.