Copper-catalyzed Huisgen cycloadditions have been recently extensively studied by polymer chemists for the synthesis of functional polymers (either end-functional or side-functional). The post-functionalization of synthetic polymers is an important feature of macromolecular engineering as many polymerization mechanisms are rather sensitive to the presence of bulky or functional groups. For example, a wide variety of telechelic polymers (i.e. polymers with defined chain-ends) can be efficiently prepared using a combination of atom transfer radical polymerization (ATRP) and CuAAC. This strategy was independently reported in early 2005 by van Hest and Opsteen [31], Lutz et al. [32], and Matyjaszewski et al. [33]. Such step was important since ATRP is a very popular polymerization method in modern materials science [34,35]. Indeed, ATRP is a facile technique, which allows the preparation of well-defined polymers with narrow molecular weight distribution, predictable chain length, controlled microstructure, defined chain-ends and controlled architecture [36–41]. However, the range of possibilities of ATRP can be further broadened by CuAAC. For instance, the ω-bromine chain-ends of polymers prepared by ATRP can be transformed into azides by nucleophilic substitution and subsequently reacted with functional alkynes (Scheme 3) [32]. Due to the very high chemoselectivity of CuAAC, this method is highly modular and may be used to synthesize a wide range of ω-functional polymers. Moreover, the formed triazole rings are not “passive” spacers but interesting functions exhibiting H-bonds capability, aromaticity and rigidity.
