CLICK FUNCTIONALIZATION OF ALIPHATIC POLYESTERS

carboxyl, 5 and hydroxyl 6-8 groups. These are important advances, but this approach is limited by its reliance on protecting group chemistry and/or linear synthetic schemes. The possibility of main chain degradation in deprotection steps and the complexity of ring monomer syntheses are the main problems with this approach. A more desirable approach is a divergent synthetic pathway in which a common reactive polymer precursor is synthesized and then elaborated upon to form many new functionalized materials. The ideal functionalization scheme relies on commercially available compounds which can be readily polymerized to high molecular weights, and which can be modified quickly under mild conditions to yield quantitative functionalization of the polyester. Ideally, any desired functionality or structure (including other reactive functionalities and other polymer segments) could be grafted onto the polymer. A promising approach to this type of divergent synthesis is the copper(I)-catalyzed Huisgen coupling between an azide and an alkyne. 9,10