Synthesis of a New Calix[4]crown‐5‐azacrown‐5 Dimeric Nano‐Tube.

Building Triazolated Macrocycles from Bis-Propargylated Calix[4]arenes and Bis-Azidomethylated Azobenzene or Stilbene

“…Covalent linking of several calixarene-type macrocycles is one of the modern synthetic strategies towards multitopic receptor systems, which possess unique properties that cannot be achieved using a single macrocyclic core [1][2][3][4][5][6][7][8][9][10][11][12][13]. In particular, the involvement of more than one linker into the connection of pairs of the cores is widely used in calixarene chemistry to obtain various multi(macrocycles) having tubular or semi-tubular shapes [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31], which have special receptor properties provided by the new receptor holes formed during macrocyclization. We have recently shown that two calix [4]arene cores could be readily linked to each other by two azobenzene or stilbene units using the K 2 CO 3promoted alkylation of parent calixarene tetrols with 4,4 -bis-bromomethylated azobenzene or stilbene, which furnished semi-tubular bis(calix [4]arenes) capable of shape changes upon irradiation/heating [32].…”