One-component air-stable iron catalysts for the ROCOP of epoxides and cyclic anhydrides

Bio-sourced polyesters have been synthesized through the ring-opening copolymerization (ROCOP) of bioderived epoxides and cyclic anhydrides using biocompatible, earth-abundant and one-component air-stable iron catalysts. • Design of earth abundant Fe complexes as efficient catalysts for the copolymerization of epoxides and cyclic anhydrides. • Synthesis of twelve bio-derived polyesters in high isolated yields. • The kinetic studies carried out support a mechanism in which the opening of the anhydride ring is the rate-determining step of the reaction. Bio-sourced polyesters have been synthesized by ring-opening copolymerization reaction of epoxides and cyclic anhydrides using air-stable one-component heteroscorpionate Fe(III)-halide catalysts. Alternating polyesters from renewable resources such as limonene oxide, endo / exo -carvone oxides and succinic and citraconic anhydrides, have been obtained with reasonable molecular weight, narrow dispersity, and high percentage of ester linkages under air conditions. There are few examples of air-stable “one-component” metal-based catalysts in the literature, tending to rely on external additives, and the results hereby reported provide hope that air-stable friendly metals complexes can be effective systems in future sustainable polymerization research. The microstructure and thermal properties of the polyesters synthesized have been investigated and discussed, and for the amorphous copolymers, the T g values have shown values from 17.5 °C to 128.5 °C.