CAREER: Olefin Upgrading with Shapeshifting Ligands

In this CAREER project, Professor Jonathan L. Kuo of the Department of Chemistry at The Pennsylvania State University is using dynamic “shapeshifting” ligands to upgrade olefins. Olefins (also called alkenes) are among the most upstream commodity chemicals – obtainable from petroleum or biomass derived feedstocks. This project seeks to construct needed chemical products from simple olefins. Successful completion of this work is expected to “widen” the base of our chemical economy, supplementing existing manufacturing pathways by (a) building synthetic “shortcuts” or (b) accessing new chemical space altogether. This work relies heavily on using nuclear magnetic resonance (NMR) spectroscopy. Selected case studies from this work will be integrated into professional development activities for graduate students; this award also supports professional development for postdoctoral scholars. The project focuses on rearrangements of olefinic small molecules that occur in proximity to electrophilic (Lewis acidic) group 10 metals, especially Pd. Many of these rearrangements involve a nucleophile adding to the internal position of a terminal alkene. The project will quantify the kinetics and thermodynamics of these rearrangements, especially examining how different tethers affect the reaction. The products of these rearrangement reactions can be used as catalysts for upgrading other olefins or can be used to model important elementary steps in catalytic Pd chemistry. Some beta-elimination reactions of H, C, and N atoms are anticipated. The characterized elementary steps will then be used to invent catalytic reactions, for example the hydroamination or hydroalkylation of olefins. These studies rely on using multiple NMR techniques. The necessary foundational knowledge, built from experimental case studies, will be compiled and disseminated as part of a hands-on NMR workshop. 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.