Catalyst Systems Based on Phenolate Complexes for Immortal Ring-Opening Polymerization of Cyclic Esters and Carbohydrates

A method comprising:

• immortal ring-opening homopolymerisation of cyclic carbonates or cyclic esters in the presence of a catalytic system, or sequential two-step ring-opening block copolymerisation of one or more cyclic monomers selected from cyclic carbonates or cyclic esters in the presence of the catalytic system, wherein the catalytic system comprises:
• a metallic complex of formula M(OAr)nXm;
• wherein M is a metal selected from Sn, Zn or Al;
• wherein OAr is a phenolate ligand;
• wherein X is an alkyl having from 1 to 6 carbon atoms, an amido group, or an alkoxide group;
• and wherein n is at least 1 and n+m is the valence of M;
• and
• an alcohol ROH or a primary amine RNH2;
• wherein R is an hydrocarbyl group, linear or branched, having from 1 to 20 carbon atoms, containing aliphatic and/or aromatic moieties;
• and wherein the alcohol or the primary amine is present in a molar ratio with respect to the metallic complex that is larger than 1;
• wherein the phenolate ligand is prepared from a phenol-based pro-ligand of formula
• wherein R1, R2 and R3 are the same or are different and are each a hydrogen or are selected from methyl, ethyl, iso-propyl, tert-butyl, neo-pentyl, cumyl, trityl, phenyl, 2,4,6-trimethylphenyl, 2,6-diisopropylphenyl.