The reaction mechanism for the organocatalytic ring-opening polymerization of L-lactide using a guanidine-based catalyst: hydrogen-bonded or covalently bound?

A guanidine-based catalyst, first involving acetyl transfer to the catalyst and the second involving only hydrogen bonding to the catalyst was used to study two alternative mechanisms for the ring-opening polymerization of L-lactide. The results showed that the hydrogen bonding pathway is favored over the acetyl transfer pathway.