DESIGNING CATIONIC ZINC AND MAGNESIUM CATALYSTS FOR COORDINATION–INSERTION POLYMERIZATION OF LACTIDE

Abstract

This review presents a synopsis of the development of cationic zinc and magnesium metal complexes as catalysts for the polymerization of lactones, with the major focus being directed toward the polymerization of lactide. By utilizing an electron-rich, neutral bis(phosphinimine) pincer ligand, cationic complexes with high ambient temperature activity for polymerization of lactide were obtained for the first time. A number of important structure–activity relationships have been established for this new class of catalyst. Recent progress toward P-stereogenic analogues of these cationic catalysts is also summarized.