A Modular Approach to Functionalized and Expanded Crown Ether Based Macrocycles Using Click Chemistry.

Tailored handcuffs: -Azide--alkyne oligomers are obtained in high yields from copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC), iterative chain growth, and protection–deprotection strategies. Intramolecular CuAAC under pseudo-high-dilution conditions then yields macrocycles with n=1–8 triazole units in the cyclic backbone (picture shows n=2; Cgray, Ored, Nblue, Hwhite).