Speaker
Spencer Pitre, Ph.D.
Speaker's Institution
Oklahoma State University
Date
2024-10-28
Time
4:00pm
Location
Chemistry A101
Mixer Time
3:45pm
Mixer Time
Chemistry B101E
Calendar (ICS) Event
Additional Information

About the Seminar:

While carbon-centered radicals have become an increasingly important tool in organic synthesis, the breadth of radical precursors available to synthetic chemists remains underdeveloped. Many of the radical precursors employed in these methods require pre-functionalization of the initial feedstock chemical, adding undesired synthetic steps while generating additional byproducts after radical formation. Our lab’s research focuses on the development and advancement of nucleophilic cobalt photocatalysis and organic photoreductants, with the unifying theme of these programs being the expansion of the breadth of carbon radical precursors available to practitioners of the field. Our nucleophilic cobalt photocatalysis strategy leverages the unique reactivity of cobalt square planar complexes, like Vitamin B12, which can engage with electrophiles in SN2 reactions, generating Co(III)-alkyl intermediates that can be photolyzed under visible-light irradiation to generate carbon-centered radicals. Our contributions in this area leverage 1,2-dichloroalkyl electrophiles for the preparation of cyclopropanes. Our lab also focuses on utilizing organic photoreductants, such as halogen-bonding photocatalysts and organic anions, for the generation of carbon-radicals from alkyl and aryl halides and carbonyl compounds, circumventing the use of tin hydrides and ground state metal reductants generally required for activation of these substrates. Our contributions leveraging substituted hydroquinone photocatalysts and 1,4-dihydropyridine anions as organic photoreductants will be presented.

 

About the Speaker:

Spencer grew up in Prince Edward Island, Canada, and obtained his B.Sc. with Honours from the University of Prince Edward Island in 2012. After completing his Ph.D. at the University of Ottawa with JuanC.(Tito) Scaiano in 2017, he joined the group of Larry E. Overman at the University of California, Irvine as a NSERC Postdoctoral Fellow. In August 2019, Spencer began his independent career at Oklahoma State University where his group currently focuses on organic single-electron photoreductants and cobalt photocatalysis.