CO₂ Utilization through Reaction with Alcohols: A Quantum Chemical Study

Reactions between alcohols and carbon dioxide have been the subject of numerous experimental studies. While such reactions are roughly thermoneutral, a direct reaction is highly activated. It has been found that certain amines enhance the reaction to the point that it runs its course quickly at or slightly above room temperature. In this contribution, we have used quantum chemical methods to arrive at some suggestions for the mechanism(s) of such reactions. Our results indicate that the addition of either an amine or CO₂ facilitates the reaction. With CO₂, the reaction is facilitated to the extent that the calculated activation energy is in accordance with the experimentally reported kinetics. Without such facilitators, all attempts at determining a transition state for the reaction were fruitless.