Organo-catalyzed/initiated ring opening co-polymerization of cyclic anhydrides and epoxides: an emerging story

Abstract

Polyesters are omnipresent in our everyday lives and their synthesis via eco-friendly methods is becoming a major challenge today. The co-polymerization of cyclic anhydrides and epoxides was first reported by...

Terpolymerization of CO2 with Epoxides and Cyclic Organic Anhydrides or Cyclic Esters

“…APC, however, often display poor chemical and mechanical properties compared to aromatic polycarbonates, and the incorporation of epoxides with various structural features does not always result in an improvement in the final properties of APC [7][8][9]. Aliphatic polyesters are another important class of biopolymers that can be conveniently obtained by the ring-opening polymerization (ROP) of cyclic esters [10][11][12][13] or by the ROCOP of epoxides with cyclic anhydrides [14][15][16][17]. Transition metal complexes generally catalyze all these polymerization processes through a coordination-insertion mechanism.…”

Ring-Opening Copolymerization Using Simple Fe(III) Complexes and Metal- and Halide-Free Organic Catalysts

“…33,53,54,56,58−60 57 The area of metal-free, organocatalysts for copolymerization is in its infancy and will no doubt emerge and potentially prove vital to future sustainable polymerization research. 7,23,45 DOSY NMR analysis confirmed that the copolymers isolated were one polymeric species and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) analysis provided evidence that there were ester and ether linkages present. However, the systems were complicated and a range of potential end groups were proposed relating to the auxiliary ligands (X = OAc or Cl) or hydrolysis and chlorofunctionalization indicative of chain-transfer reactions occurring upon termination and isolating the polymers with the acidified MeOH/HCl work-up (see the Supporting Information, Figures S37−S42), or possibly cyclohexane/cyclohexene from potential Meerwein−Ponndorf−Verley reduction/Oppenauer oxidation side reactions.…”

“…Additionally, it is important to note that the molecular weight increased as the CHO was further distilled and purified (from singly distilled to triply distilled); this agrees with that reported in the literature. 7,37,51 Also, triply recrystallized PA using toluene solvent was found to be more effective than purification via hot filtration using chloroform and subsequent sublimation of the PA. It was discovered that PPNCl could carry out the reaction solely; in agreement with other reports, [Fe] was not participating cooperatively with PPNCl in the reaction.…”

“…23 This was recently well reviewed by Dagorne, Le Bideau, and coworkers. 7 ■ RESULTS AND DISCUSSION ROCOP of Cyclohexene Oxide and PA in Toluene Solvent. The initial investigations into the ROCOP of the internal epoxide, CHO, and aromatic PA were conducted using the Fe (7) catalyst and the PPNCl co-catalyst as part of a binary catalytic system (see the Supporting Information, Table S1) to target the formation of the polyester, poly(1,2-cyclohexylene-1,2-phthalate) {poly(CHO-co-PA)}, as is commonly employed in the literature for both Fe and other elements, in toluene solvent.…”

“…7 ■ RESULTS AND DISCUSSION ROCOP of Cyclohexene Oxide and PA in Toluene Solvent. The initial investigations into the ROCOP of the internal epoxide, CHO, and aromatic PA were conducted using the Fe (7) catalyst and the PPNCl co-catalyst as part of a binary catalytic system (see the Supporting Information, Table S1) to target the formation of the polyester, poly(1,2-cyclohexylene-1,2-phthalate) {poly(CHO-co-PA)}, as is commonly employed in the literature for both Fe and other elements, in toluene solvent. 33 Although the internal epoxide, CHO, is a more challenging substrate compared to the alternatives due to the high steric hindrance, this more rigid and sterically bulky framework allows access to polyesters with higher and more favorable T g values.…”