Mechanistic Investigations of Nickel-Promoted C-Heteroatom Bond Making Reactions

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The impact of modern chemical industry on our lives is breath-taking in many respects. The adage, "What in the World Isn't Chemistry?!" reflects the fact that more or less every touchable "thing" around us (pharmaceutical and agricultural products, paints, oils, adhesives, plastics and other materials, etc.) was created, in one way or another, through chemistry. And beyond the practical contributions of chemistry to modern life and producing "things", the concepts and theories of the chemical sciences have enriched our understanding of the universe, creation, evolution, and life itself in multiple and complex ways. Indeed, chemistry helps makes sense of the universe, starting at the atomic and molecular levels, and going on to bulk matter and larger macromolecules of life, and finally to the planets and stars. Hence, the expression: Chemistry, the central science. This proposal describes a research program devoted to investigating a subset of chemical reactions that teach us how chemical bonds are formed and broken. This knowledge is then put into practice to elaborate efficient and environmentally benign methodologies for the synthesis of so-called organic chemicals that have uses in different sectors of the chemical industry, from pharmaceuticals to agrochemicals and beyond. More specifically, we propose to closely examine the interactions of chemical entities called "ligands" with metal atoms that are capable of promoting and controlling various elementary reactions that define bond making and breaking steps. The focus of this study will be the earth-abundant transition metal nickel, which will be combined with various ligands to give "complexes" that act as stable yet reactive pre-catalysts. The long-term objectives of our research program include devising routes for the so-called "functionalization" of C-H bonds and amination of olefins. These are processes whereby chemists convert abundant and less "functional" (less useful) carbon-based materials into new molecules and materials featuring so-called heteroatoms such as nitrogen and oxygen that offer an infinite set of new properties and functions to the original material. Our strategy for achieving this goal is to build on the discoveries made during our previous research studies. Thus, the conceptual advances we have registered on the first step of the C-H functionalization program, i.e., the activation of the fairly inert C-H bonds will allow us to focus on the next task at hand, i.e., the conversion of cyclometallated species into products featuring newly formed C-heteroatom linkages. This would then enable us to define the conditions and variables that facilitate the conversion of C-H bonds into functional materials and products. Similarly, we would use our previous findings to develop new ways for conversion of olefins into more valuable amines.