Key points are not available for this paper at this time.
A metal-free approach to the living ring-opening polymerization (ROP, shown schematically) of lactide has been developed using strongly basic amines such as 4-(dimethylamino)pyridine as transesterification catalysts. These organic catalysts must be used in combination with a nucleophile such as an alcohol, which is the actual initiating species.
Nederberg et al. (2001) studied this question.