Student Hosted Colloquia: Professor Nicholas Ball, Pomona College (Host: Cris Woroch)
**This seminar is available for in-person attendance.**
"Synthetic Strategies toward Fluorosulfurylation of Organic Molecules and Sulfur-Fluoride Exchange (SuFEx)"
About the Seminar
Sulfur-fluoride exchange (SuFEx) chemistry is emerging as a promising synthetic tool in chemical biology, material science, and synthetic chemistry. In synthesis, sulfur (VI) fluorides show unique promise as synthons in organic chemistry due their stability versus other sulfur (VI) halogen analogues. Key to the adoption of SuFEx chemistry is the development of efficient modes to synthesize and react sulfur (VI) fluorides. Research initiatives employing group 2, and transition-metal chemistry toward the synthesis of sulfonyl fluorides will be described. New SuFEx methods that react a broad set of S (VI) fluorides with carbon, oxygen, and nitrogen-based nucleophiles towards structurally diverse S(VI) compounds will also be presented.
A focus will be on a new SuFEx reaction to synthesize nitrogen-based sulfonylated compounds from a variety of S(VI) fluorides mediated via a Lewis acidic calcium salt will be described. Under a unified set of reaction conditions, sulfonyl fluorides, fluorosulfates, and sulfamoyl fluorides can be coupled with a variety of amines to synthesis a wide array of aryl and alkyl sulfonamides, sulfamides, and sulfamates in good to excellent yield. Computational and NMR kinetic studies that aim to elucidate the mechanism of Ca-activation will be discussed. Lessons learned from the mechanistic studies have led to preliminary data suggesting Ca-catalysis is possible.
About the Speaker
Dr. Nicholas Ball grew up in Chattanooga, TN. He received his B.A. in Chemistry at Macalester College where he conducted undergraduate research in the lab of Professor Ronald G. Brisbois focusing on a modified Songashira reaction generating bisarylethynes. After Macalester, he joined the laboratory of Professor Melanie S. Sanford at the University of Michigan - Ann Arbor. In the Sanford Lab he studied the structure and reactivity of Pd–fluoride and trifluoride complexes toward the formation of organofluorine compounds. After completing his Ph.D. in 2010, he headed to the California Institute of Technology to pursue his postdoctoral studies with Professor David A. Tirrell as a NIH Postdoctoral Fellow. In the Tirrell laboratory, he transitioned into chemical biology studying the role of selenium-based amino acids for the identification of low-abundant proteins. Nicholas started as an Assistant Professor at Amherst College in 2013. In 2015 Dr. Ball joined the faculty at Pomona College and is now an Associate Professor of Chemistry with tenure. He is a 2020 Henry Dreyfus Teacher scholar, NIH R15 grantee, and named a 2021 Chemical and Engineering News LGBTQ+ Trailblazer.
Image Credit: Branden Grimmett