New multifunctional ligation strategies for tuning transition metal reactivity

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As stated by the 2007 Priestley Medalist, George M. Whitesides, "almost everything in chemistry is catalyzed." Transition metal catalysts in particular have risen to the challenge of providing solutions for many of the problems of modern synthetic chemistry, specifically with respect to the development of new chemical processes that convert abundant resources into value-added products in an efficient, selective, and environmentally friendly manner. The impact of transition metal catalysis was recognized in the awarding of the 2001 and 2005 Nobel Prizes in Chemistry. The development of such reactive catalysts represents an ongoing challenge that spans a range of chemical disciplines (e.g. organic, inorganic, environmental). Notably, all such breakthroughs are rooted in the fundamental study of transition metal reactivity. In this context, research in the Turculet group targets the preparation of reactive transition metal complexes that exhibit new and/or improved reactivity properties by virtue of their unique construction. Key to this endeavor is the design and synthesis of new ancillary ligands that impart novel structural and electronic characteristics to the ensuing metal complexes. The proposed research seeks to develop the metal chemistry of new ancillary 'pincer'-type ligands that feature previously under-explored, formally anionic heavier main group element donors (e.g. Si, P). Overarching questions that we seek to address in this research include: (i) Can such pincer complexes be prepared, and do they exhibit new or unusual reactivity properties? (ii) Does the replacement of traditionally employed anionic donors (e.g. C, N) with their heavier congeners (e.g. Si, P) in such complexes provide improved reactivity in established catalytic reactions (e.g. transfer hydrogenation)? (iii) Can electron-rich complexes featuring such 'heavier-element' pincer ligands mediate challenging bond activation reactions (e.g. N2, C-H) that are of fundamental importance for the utilization of abundant but unreactive resources? These studies will advance our understanding of how metal-ligand interactions influence reactivity, enabling the design of metal catalysts that can mediate new and increasingly challenging substrate transformations.