Novel Synthetic Methods

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With this award, the Chemical Synthesis Program of the NSF Division of Chemistry is supporting the research of Professor Gevorgyan. His research team is developing novel methods for converting abundant and cheap feedstock materials into value-added products. Carbon-hydrogen bonds plentifully present in organic molecules are targeted for useful elaboration. However, the high strength of the carbon-hydrogen bond prevents its easy breakage and thus may require forcing conditions such as high reaction temperatures, or the use of precious and rare transition metals. Such chemistry may also require the use of highly unstable reagents, which then raise safety concerns. Professor Gevorgyan’s team is investigating very mild and safe transition metal-free methods for generation and manipulation of various reactive species from simple and stable precursors under visible light irradiation. Engagement of this approach allows for mild, efficient, and selective functionalization of organic molecules. The broader impacts of this project include providing new and effective routes into building block molecules of importance in chemical biology and materials science. Moreover, this research has the potential to significantly reduce the cost of chemical reagents needed, and thus have a favorable impact on process efficiency and economy. In addition, Dr. Gevorgyan is actively engaging in outreach activities for recruiting undergraduate students into research, including members of groups that are currently underrepresented in science. Student involvement in research at UT-Dallas is projected to provide a forum for the expression and cultivation of student talent and creativity and enhance their career possibilities.In this project, Professor Gevorgyan’s team is developing new mild transition metal-free methods for generation of aryl-, vinyl-, alkyl- and heteroatom-centered radicals to unlock their potential in modern organic synthesis. The approach under development relies on single electron transfer (SET) reduction of electrophilic intermediates with nucleophilic reagents. This can be accomplished under mildly thermal or visible light-induced conditions. The initially forming radicals may undergo atom transfer (AT) or hydrogen atom transfer (HAT) to generate a transposed radical, which then is involved in further synthetic transformations, including aliphatic C(sp3)−H bond functionalization, desaturation, or cascade cyclization reactions. The factors favoring efficient SET, AT, and HAT processes are under investigation. These methods, if fully developed, would not only deepen our understanding of electron-transfer chemistry for generation of reactive intermediates, but would also substantially broaden the arsenal of tools available for synthetic and medicinal chemists for synthesis and late stage modification of complex 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.