Synthesis of neoglycopolymers by a combination of "click chemistry" and living radical polymerization

The synthesis of novel well-defined alkyne side chain functional polymers featuring narrow molecular weight distributions (PDI = 1.09-1.17) by living radical polymerization is described. Grafting of protected and unprotected carbohydrates is achieved via either a C-6 or an anomeric azide (alpha or beta) onto these polymers by Cu(I)-catalyzed "click chemistry", providing a simple and efficient route to synthetic glycopolymers. The strategy provides an extremely powerful tool for the synthesis of libraries of materials that differ only in the nature of the sugar moiety presented on a well-defined polymer scaffold. A library of multivalent ligands were then prepared following a "coclicking" synthetic protocol, and the reactivity of these glycopolymers in the presence of concanavalin A and Ricinus communis agglutinin, model lectins able to selectively bind appropriate mannose and galactose derivatives, respectively, was assessed.