Regioselective Functionalization of the para-Positions at the Calix[4]arene Upper Rim

Abstract

This review summarized and systematized the currently known methods of substituting phenolic fragments of calix[4]arenes in the para-position, mainly focusing on the conditions of regioselective carrying out such processes. The reactions of the further transformation of the inserted functional groups, which allows the expansion of the family of para-substituted calixarenes, are also considered. These reactions can synthesize inherently chiral calix[4]arenes with asymmetric substitution on the upper rim.

Epichlorohydrin-based CuAAC dendrimers with a calix[4]arene core and polar hydroxyl/oxyethyl terminal groups: synthesis, aggregation and use in catalysis

“…This process is regulated by selective modification of the lower rim: unsubstituted aromatic fragments of calix[4]arene more easily enter electrophilic substitution reactions in the benzene ring due to the activating effect of the unsubstituted hydroxyl group. 30,31 Due to this regioselectivity, we have previously obtained di/tetra aromatic calix[4]arenazides. 32 Thus, it is possible to control the branching of the final dendrimer and to study the effect of branching on the properties of the latter.…”

“…Calix[4]arenes 1 , 30 2 , 31 3 , 35 1-bromo-4-(octyloxy)benzene 13 , 38 dendrons 10 , 14 29 and 1,3-bis(prop-2-yn-1-yloxy)propan-2-yl 4-methylbenzenesulfonate 9 52 were synthesized using methods from the literature.…”