Congratulations to Dr. Sieber on his NSF Career Award

July 18, 2022

Dr. Sieber recently received a NSF Career award for the Development of Stereoselective Cu-Catalyzed Reductive Coupling Reactions. His Abstract is below:

With the support of the Chemical Catalysis program in the Division of Chemistry, Professor Joshua Sieber of the Department of Chemistry at Virginia Commonwealth University (VCU) will investigate and develop new chemical tools to synthesize amine-derived polar organic compounds. Amine-derived polar organic compounds are prevalent in nature and the pharmaceutical industry that are used and developed to study biological processes and to create new therapeutics for the treatment of human diseases. However, such compounds are often extremely difficult to access and prepare synthetically. The goals of this research are to develop new synthetic tools to enable easy access to these important amine-derived polar organic compounds using benign copper as the chemical catalyst. Studies will also be performed to understand how these processes work so that the efficiency of these new techniques can be continually improved. The educational objective of this CAREER proposal aims to recruit and prepare a diverse STEM (science, Technology, Engineering and Mathematics) workforce for careers at the frontiers of the chemical sciences through “hands-on” training of the scientific method using synthetic organic chemistry. This goal will be achieved through: 1) introducing Richmond Public High School students to careers in synthetic organic chemistry through interactive classroom visits and opportunities to perform scientific research in the principal investigator’s laboratory in the summer, and 2) developing a new undergraduate level advanced organic chemistry laboratory at VCU aimed at providing synthesis skills to students for applications to industrial careers in chemistry. Development of synthetic methodology to enable the construction of C–C bonds is at the core of organic chemistry. Having a “tool box” full of these C–C bond forming reactions enables the synthetic chemist to access any molecular target desired for endless applications to biology, medicine, chemical probes, material science, etc. Organic molecules utilized by nature and prepared synthetically for use in all areas of the sciences often contain amine and/or alcohol functional groups. In many cases, multiple alcohol and/or amine functional groups are present within the same molecule, giving rise to poly(ol), poly(amine), or aminoalcohol motifs, all with unique stereochemistry. However, synthesis of such compounds in a stereocontrolled fashion is often very difficult due to the polar nature of these functional groups, especially for specific substitution patterns leading to the wrong polarity profile required for typical two-electron chemical processes. This proposal aims to develop new stereoselective and regiodivergent Cu-catalyzed processes to address this challenging situation through the introduction of multiple heteroatom groups in the final product in a single reaction step to allow for convenient and straightforward access to chiral poly(heteroatom)-containing compounds. This goal will be achieved through the investigation of allenamides in asymmetric Cu-catalyzed reductive coupling reactions with aldehyde and imine electrophiles. Development of these processes is expected to: 1) improve the synthetic efficiency for the preparation of molecular architectures that are difficult to prepare by other techniques; 2) allow for the conversion of basic feedstocks to a wide range of enantiopure chiral building blocks that are of significant importance in natural product synthesis, new catalyst design, drug discovery and development, and material science, and 3) provide mechanistic insights to aid in the future development of general, stereoselective catalytic umpolung (polarity-reversed) processes. Finally, the principal investigator will be engaged with the local community in Richmond to support the mentoring and recruiting of new students in STEM (science, Technology, Engineering and Mathematics) disciplines through hands-on classroom demonstrations at local high schools and through research opportunities for undergraduates and high school students in the principal investigator’s laboratory.