Developing New Reactions and Catalysis via Designer Ligands for Organometallic Chemistry

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My research program combines chemical synthesis, catalysis and polymerization to tackle meaningful fundamental and applied questions that are relevant to society. More specifically, the primary goal of my research is to prepare new and unusual metal-containing molecules to catalyze the synthesis of pharmaceuticals, agrochemicals, important chemical intermediates, fine chemicals and materials. From a pedagogical perspective, great emphasis is placed upon learning requisite laboratory techniques, the development of critical thinking and communication skills, and the ability to work in a safe and thoughtful manner. Over the next 5 years my research team will synthesize late transition metal complexes that are stabilized by designer NNN-pincer ligands. These species have been targeted as potential sources of reactive 14-electron, T-shaped intermediates, from which a wide range of catalytic pathways can be envisioned. Preliminary work has revealed that the hemilabile phosphinimine donors act cooperatively with the metal centre to activate various small molecules, including H2, CO and silanes. The products of these reactions will be studied to ascertain their competence in mediating a range of catalytic processes. For example, the silicon atom in our rhodium silylenes (LRh=SiR2) is expected to position substrates to facilitate the activation of challenging bonds, such as C-F. Installation of fluorine into organic molecules is important to the pharmaceutical industry as upwards of 30% of new drugs contain fluorine. Related complexes that bear multiple bonds between rhodium and germanium, tin and boron will also be prepared and their reaction chemistry explored in depth. Another direction in my laboratory will focus upon the preparation of phosphazide (R3P-(N3)-R) ligands, and metal complexes thereof. Because phosphazides are prone to loss of N2, their coordination chemistry is largely unrealized. However, the ease with which pendant groups can be fine-tuned, their coordinative versatility, and the ability for conversion to phosphinimines, suggests that phosphazides offer potential as ligands in inorganic chemistry and homogeneous catalysis. We will develop routes to stable, and thus, more easily studied phosphazide-containing ligands. Given the tendency of f-elements to accommodate high coordination numbers, they will be used for initial complexation studies.    In summary, this work has great potential for addressing issues currently confronting Canada (e.g. conversion of atmospheric N2 into agricultural products, new pharmaceuticals to combat disease), and developing new technologies that will improve the lives of Canadians. For example, the creation of methods for the direct installation of carbon, silicon and fluorine represents an efficient and cost-effective route to valuable organic molecules. Ultimately, this chemistry will afford new catalytic systems and provide valuable training to the next generation of scientists.