The focus of this research involves the development of general organocatalytic strategy for the living ring opening polymerization of strained esters. Nucleophilic carbene catalysts from thiazolium, imidazolium and imidazolinium families will be examined for the polymerization of strained cyclic monomers and other monomer systems. Further, a variety of C-H insertion reactions will be studied using imidazolin-2-ylidines with activated C-H bonds to afford air stable carbenes. The in situ methodology used will provide for rapid screening of libraries of catalysts to give basic understanding of catalyst structure on polymerization rates, the degree of control, the substrate tolerance and range of molecular weights accessible with these strategies. Mechanistic investigations will address the relative rate of monomer activation versus transesterification to define the kinetic window where well-controlled polymerization can be expected. Extension of this organocatalytic method to the ring opening of lactams and transesterification of phosphate esters will also be investigated.
With this award, the Organic and Macromolecular Chemistry Program and the Office of Multidisciplinary Activities are supporting the GOALI project of Dr. Robert M. Weymouth of the Department of Chemistry at Stanford University and Dr. James L. Hedrick of IBM Research. The collaboration will focus research efforts on developing organic catalysts for use in living polymerization processes. The project will develop new synthetic methods for controlled polymerization reactions, obtain new insights into nucleophilic catalysis of transesterification reactions and develop a new class of organocatalysts for use in fine chemical synthesis. The project will enable the training of graduate students and a postdoctoral in a highly interdisciplinary, collaborative effort between an academic and an industrial laboratory and there is further potential for broader impact of the work in terms of creating a cleaner environment.
