STRUCTURE-STEREOSELECTIVITY INSIGHTS INTO THE ASYMMETRIC KINETIC RESOLUTION POLYMERIZATION OF SUBSTITUTED POLY(CAPROLACTONES)

Isotactic polyesters are a high value polymeric material of interest due to their comparable thermomechanical properties to polyolefins, while also being degradable under industrially relevant conditions. Current methods to synthesize these materials however, require the utilization of chiral pool reagents with a predefine stereocenter. To expand the scope of isotactic polyesters, methodologies need to be developed to convert racemic monomeric feedstocks into enantioenriched materials. This thesis discusses the intricacies in the utilization of chiral phosphoric acids, a type of Brønsted acid catalyst, for the asymmetric kinetic resolution polymerization of poly(substituted caprolactones). Known to engage carbonyl containing substrates in a bifunctional activation manner, we envisioned these catalysts as a complementary approach to organometallic catalysts already utilized. Through the synthesis of a library of racemic methyl caprolactones, we were able to examine how the utilization of different constitutional isomers affect polymerization kinetics, degree of stereocontrol, and resultant material properties. This work highlights the multivariate complexity of this polymerization system in terms of both catalyst and monomer structure in order to tune the observed stereocontrol of each polymeric material.