CAREER: Understanding and Directing Selectivity in Functionalizations of Strong Covalent Bonds Utilizing Coordination-Sphere Effects

With support of the Chemical Structure, Dynamics & Mechanisms-B Program of the Chemistry Division, Shuming Chen of the Department of Chemistry and Biochemistry at Oberlin College will use computational models to help understand and steer selectivity in reactions catalyzed by transition metal-ligand complexes. These reactions can be used to transform strong covalent bonds, such as carbon-carbon and carbon-hydrogen bonds, into usefully functionalized compounds, with wide-ranging implications for catalytic chemistry in materials synthesis, natural product total synthesis and pharmaceutical drug candidate synthesis. This project will also pursue educational initiatives aimed at fostering greater involvement in scientific research for students from underrepresented backgrounds. These initiatives encompass a variety of activities, including the Seed Experience in Authentic Research for First-Years (SEARF) workshop, which offers first-year chemistry students at Oberlin a straightforward entry point into authentic research. Collaborative development of open-source pedagogical modules will address challenges associated with teaching transition-metal mechanisms in undergraduate classrooms. To further promote equitable access to scientific research, the project will also provide financial support for undergraduate students to perform research throughout the academic year and to high school students during the summer months. While mechanistic insight derived from computations is increasingly used to inform the development of new synthetic methodologies, many important transition-metal-catalyzed systems remain challenging for computationally-guided reaction design. The overarching research objective of this project is to develop and apply effective computational models to understand and predict transition-metal-catalyzed functionalizations of strong covalent bonds. Building on preliminary results that revealed multiple types of unexpected coordination-sphere effects in C–H, C–C and C=C functionalization systems, Dr. Chen and her research group plan to carry out computational studies that will shed light on the interactions between coordination-sphere elements. They aim to elucidate the power structure of coordination-sphere effects, including the primary (core ligand moieties), secondary (pendant ligand moieties), and tertiary (solvent shell) coordination spheres, in key mechanistic steps that often constitute the energetic bottlenecks of synthetically useful chemical transformations. Their efforts have the important potential to quantify these effects on measurable reaction outcomes and reveal productive directions for reaction design based upon coordination sphere effects. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.