Supported by the Chemical Synthesis (SYN) Program in the Division of Chemistry, Professor Guangbin Dong of the University of Chicago is leading a team of researchers to invent new ways to make carbon-carbon bonds. Carbon-carbon bonds are an essential part of almost all organic chemicals. These important bonds form the backbone of most medicines and plastics (polymers) and thus are produced on massive scales. Dr. Dong?s research focuses on forming carbon-carbon bonds from simple, inexpensive and non-toxic stating materials without also producing by-products which must be separated and/or discarded. This approach follows the principles of ?Green Chemistry? in that the new synthetic routes to commodity and specialty chemicals are more environmentally friendly. The research grant also supports the education of students at many levels. Professor Dong is actively engaged in the "ChiS&E" program to provide early chemistry education to Chicago public middle-school students. He is also involved in the Collegiate Scholars Program to teach high school students and the Leadership Alliance Summer Research Early Identification Program (SR-EIP) to offer laboratory research experiences to undergraduate students. These outreach activities encourage a diverse group students to explore careers in science and engineering while learning and actively contributing to research.
The goal of this project is to develop byproduct-free ketone-olefin coupling reactions via transition metal (TM)-catalyzed carbon-hydrogen (C-H) bond activation. These approaches could serve as more environmentally-friendly approaches to access alkylated ketones. The research plan employs bifunctional templates to enable enamine/TM or imine/TM cooperative catalysis. The team's objectives are first, to develop a direct branched-selective alpha-alkylation of ketones with simple olefins via enamine/TM cooperative catalysis and second, to develop a direct alkylation of ketones with simple olefins via imine/TM cooperative catalysis. Carbonyl functionalization plays a central role in organic synthesis. Enolate alkylation and conjugate (alkyl) addition represent two common and important approaches for introducing alkyl groups at carbonyl positions.. Notably, these reactions are not economically- or environmentally-friendly processes mainly due to the use of stoichiometric halogen-based alkylating agents and/or stoichiometric organometallic species. Here, Professor Dong and his team employ a TM-catalyzed enamine or imine-mediated C-H functionalization strategy to achieve ketone alkylation using simple unactivated olefins as the alkylating agents. This approach is considered more sustainable than current methods because stoichiometric by-products are not generated and the reaction conditions are generally pH- and redox-neutral, thereby tolerating a broad range of functional groups. From a practical viewpoint, olefins are typically a cheaper and more readily available feedstock than the corresponding alkyl halides or organometallic species. Byproduct-free ketone alkylation methods using regular olefins as the alkylating agents are developed through the new bifunctional catalysts. Professor Dong and his team are engaged in several outreach activities, including introducing grade school students to chemical concepts. Integrating educational activities of students from diverse age groups and backgrounds into the existing research program has been a primary goal of the research group.
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.
