Recent Advances in Metal-Mediated Stereoselective Ring-Opening Polymerization of Functional Cyclic Esters towards Well-Defined Poly(hydroxy acid)s: From Stereoselectivity to Sequence-Control

摘要: Poly(hydroxy acid)s are a family of biocompatible and (bio)degradable polyesters with various outcomes in different domains application. To date, poly(hydroxy best prepared by ring-opening polymerization (ROP) the corresponding cyclic esters. Using racemic chiral monomers featuring side-chain groups enables to access, providing stereoselective catalyst/initiator system is implemented, stereoregular functional polymers, thereby improving their physico-chemical properties ultimately widening range uses. Here, we highlight few important advances metal-mediated ROP esters towards synthesis (functional) that have recently been disclosed, emphasizing on β- γ-lactones, diolide O -carboxyanhydride (OCA) yttrium-based catalysis. Fine-tuning substituents flanked catalyst ligand reaching syndiotactic also isotactic microstructures. The stereocontrol mechanisms at work probable origin, relying steric but electronic factors imparted particular substituents, discussed. Taking advantages such ROPs, original copoly(hydroxy gradient or alternated patterns then become accessible from use mixtures chemically different, oppositely configurated enantiopure monomers.