Catalytic copolymerization of CO₂ and diols using CeO₂ and 2-cyanopyridine

Direct and catalytic polymerization of CO₂ and diols to polycarbonates is a promising technology as a simple and environmental-benign method. Generally, the synthesis of organic carbonates from alcohols and CO₂ needs selective catalysts and effective dehydrating agents because of the serious equilibrium limitation, One of the conventional synthesis methods of organic carbonates is the reaction of alcohols with phosgene. However, the problems of this phosgene method are the usage of poisonous phosgene and large amount of salt byproduct for the neutralization Therefore the impact of the present work is related to the substitute for phosgene with CO₂. There are no reports on the direct catalytic polymerization of CO₂ and diols. and the present work is the first example using CeO₂ catalyst and 2-cyanopyridine promotor. providing the alternating cooligomers in high diol-based yield (up to 99%) and selectivity (up to >99%). This combination of CeO₂ and 2-cyanopyridine is also effective to various diols including linear C4-C10 α,ω-diols to give high yields of the corresponding cooligomers. which cannot be synthesized by conventional methods such as copolymerization of CO₂ and cyclic ethers and ring-opening polymerization of cyclic carbonates.