Enzymatic ring-opening polymerization and polycondensation for the green synthesis of polyesters

Enzyme-catalyzed polyester synthesis has been briefly reviewed with focusing on the studies achieved mainly by our group. This article describes the polyester synthesis based on the reaction mode catalyzed by enzyme with using lipase in major and protease in minor. First, ring-opening polymerization of cyclic esters (lactones), where the macrolide monomers showed a higher polymerizability by lipase catalyst than smaller ring-sized lactones. This tendency is the reverse with the anionic and metal (Zn) catalyzed polymerizations, which was explained from the specific mechanism of the enzymatic reaction. Chemoselective and enantioselective as well as end-functionalizing polymerizations were mentioned. Second, condensation polymerization (polycondensation), where two modes of reactions using oxyacid or its ester as monomer and carboxylic acid or its ester and diol as monomers were shown. Third, ring-opening addition-condensation polymerization, where carboxylic anhydride and diol monomers were reacted involving dehydration. Finally, advantageous aspects of enzymatic polyester synthesis are described in terms of conducting green polymer chemistry. Copyright (c) 2015 John Wiley & Sons, Ltd.