RUI: Advancing Stereoselective Synthesis Through Allyl Organosamarium Intermediates

Western Washington University, Bellingham WA

Investigators

Abstract

With the support of the Chemical Synthesis program in the Division of Chemistry, Professor Gregory O’Neil of Western Washington University will study new reactions to synthesize carbon-based molecules with control of their three-dimensional stereochemistry. To function properly, many carbon-containing medicines, proteins, and polymers require specific stereochemistry, which is based on the specific three-dimensional arrangement of their atoms. Synthesizing these molecules, therefore, requires reactions that proceed with precise control of the three-dimensional arrangement of atoms in the resulting products. Dr. O’Neil and his group will investigate new reactions between readily available carbon-based molecules and samarium to achieve this goal. These reactions can be conducted in the presence of water, thereby avoiding the need for specialized equipment. In this way, the reactions may be readily adopted by others and are well suited for incorporation into an Introductory Organic Chemistry Laboratory course as a course-based research experience. In this project, a diverse group of undergraduate and M.S. students will be trained in modern synthetic organic chemistry, learn a variety of research methods including advanced analytical techniques, and become integrated into the scientific community through attendance at professional meetings and dissemination of results. Reactions that produce carbon atoms with control of their stereochemistry are required for the synthesis of many functional organic molecules. The goal of this project is to investigate allyl organosamarium complexes, generated from the reaction of allylic benzoate esters and phenyl sulfones with samarium diiodide and water, as synthetic intermediates for the stereoselective synthesis of asymmetrically-substituted (stereogenic) carbon atoms. Results from the research are expected to provide a versatile alternative to the existing challenge of stereoselectively synthesizing functional stereogenic carbon-containing molecules of interest to various disciplines such as biology and materials science. Reactions to be developed will be capable of stereoselectively creating stereogenic carbons in products that would be difficult to prepare with other methods. Combined with their ease of execution, a broad scope, predictable and controllable stereoselectivity, and the potential for catalysis, the methods developed may have a significant positive impact on the synthesis of important organic molecules while also increasing our fundamental understanding of organosamarium chemistry. Broader impacts and educational components of the project include the development and implementation of a four-day course-based research experience for undergraduates, with students investigating the impact of substrate structure on stereospecificity. This experience will teach students concepts related to stereochemistry as well as providing training in organic synthesis and methods for molecular characterization. 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.