Polyester Synthesis via Chemoselective Dehydration Polycondensations

Significance

One-step synthesis of aliphatic polyesters with pendant hydroxyl groups (3) was achieved by chemoselective polycondensation of dicarboxylic acids (1) and diols (2) containing pendent hydroxyl groups. The reactions were catalyzed by rare-earth trifluoromethanesulfonates under mild conditions. The polycondensation proceeded without noticeable racemization in the case of chiral dicarboxylic acids, and lower toxicity of the catalyst Sc(OTf)₃ toward organisms was observed. The pendant hydroxyl groups of the polyester readily undergo chemical modification, such as glycosidation.