Efficient Functionalizations of Heteroatom-Bridged Calix[2]arene[2]triazines on the Larger Rim

Heteroatom-bridged dichlorinated calix[2]arene[2]triazines, which were synthesized from the fragment
coupling reactions of cyanuric chloride and various aromatic dinucleophiles, are a unique type of platform
for the construction of functional macrocyclic host molecules. Utilizing a very convenient and
straightforward nucleophilic displacement reaction of dichlorinated tetraoxacalix[2]arene[2]triazine by
various chelating group-containing amines, a number of functionalized tetraoxacalix[2]arene[2]triazines
on the larger rim were efficiently synthesized in good yields. The resulting tetraoxacalix[2]arene[2]triazines armed with two 2,2‘-bi(pyridinyl)amino or two bis(2-pyridinemethyl)amino groups selectively
formed 1:1 complexes with Cu2+ ion through most probably a chelating interaction effect.