Effective synthesis of dialkyl carbonate from CO2 and alcohols using dibutyltin(IV) oxide catalyst and dehydrating agents

The combination of a dibutyltin(IV) oxide catalyst with an ortho ester as the dehydrating agent exhibited high activity for the direct synthesis of diethyl carbonate from CO₂ and ethanol in 78% yield. With water as a by-product limiting the reaction, a recoverable dehydrating agent is required. When alkoxysilanes were employed for this purpose, various dialkyl carbonates were obtained in yields of 33–45%.