Catalyst chelation effects in organocatalyzed ring-opening polymerization of lactide

Abstract

(-)-Sparteine is a proven organocatalyst for the ringopening polymerization (ROP) of L-lactide, which affords polymers of controlled molecular weight and narrow polydispersity. The recent worldwide shortage of (-)-sparteine has necessitated the identification of simple and cost-effective replacement ROP catalysts. A series of commercially available molecules was first identified through molecular modeling and then subsequently investigated for polymerizing L-lactide. The modeling proved very useful at predicting spatial relationships and nitrogen geometries that greatly aided in the rapid identification of various alkyl amines as alternative organocatalysts. © 2011 American Chemical Society.