Direct Cyclic Carbonate Synthesis from CO₂ and Diol over Carboxylation/Hydration Cascade Catalyst of CeO₂ with 2-Cyanopyridine

We first achieved direct synthesis of propylene carbonate from CO 2 and 1,2-propanediol in excellent yield (>99%) using a carboxylation/hydration cascade catalyst of CeO 2 with 2-cyanopyridine. The catalyst system can be applied to syntheses of various cyclic carbonates, including 6-membered ring carbonates that are difficult to synthesize in high yields (62−>99%).