Collaborative Research: Enhancing Chemoselectivity and Efficiency Through Control of Axial Coordination in Rh(II) Complexes: An Experimental and Computational Approach

University Of Tennessee Knoxville, Knoxville TN

Investigators

Abstract

With the support of the Chemical Synthesis program in the Division of Chemistry, Ampofo Darko of the University of Tennessee-Knoxville and Dean Tantillo of the University of California-Davis, will study and develop new methodology to improve the efficiency and function of rhodium-based catalysts for organic transformations that result in the generation of difficult-to-produce compounds. The research team will utilize their combined strengths in experimental synthesis methodology and computational chemistry to probe factors that determine the outcomes of the chemical reactions, and will use the generated data to guide the further development of these rhodium-based catalysts for more challenging reactions. The broader impacts of this research will include providing in-depth research training for a diverse group of graduate and undergraduate students at the interface of computational and synthetic chemistry, thereby empowering the next generation of chemists by equipping them with a valuable set of research skills. Dr. Darko will partner with local Knoxville non-profit Centro Hispano De East Tennessee to provide an opportunity for underserved high school students in the local community to work on original research in the Darko lab and learn about opportunities and possible careers in chemistry. Through a combination of computational and experimental efforts, this collaborative project seeks to uncover new concepts in catalyst control in dirhodium(II,II) paddlewheel complexes by studying remote bonding interactions involving the catalyst. The research team will design a bridging scaffold that has built-in ligands that are capable of manipulating reactivity from the distal rhodium site. The team will identify key parameters that can be applied generally to the syntheses of next-generation heteroleptic dirhodium(II,II) paddlewheel complexes, adding to the structural diversity of currently available analogues. The new dirhodium complexes will be employed as catalysts for metal-carbene transfer chemistry, with an emphasis on probing the effect of remote interactions on catalyst efficiency and selectivity for cyclopropanation or arene insertion reactions. These studies are expected to establish fundamental trends in reaction chemoselectivity when perturbing axial coordinating groups on the dirhodium(II,II) paddlewheel core. An understanding of the chemoselectivity profile of the new complexes is expected to yield rich dividends in establishing the role of remote coordination in the synthesis of complex organic molecules. 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.