Ketone Alkylation Using Simple Olefins: A Sustainable Chemistry Approach

University Of Chicago, Chicago IL

Investigators

Abstract

With the support of the Chemical Synthesis program in the Division of Chemistry, Professor Guangbin Dong of the University of Chicago is studying new catalyst-based strategies to achieve the byproduct-free generation of value-added products from simple precursors of the ketone and olefin compound classes. Ketones are a widespread class of organic molecules that have many applications in chemical manufacturing; however, established methods to derivatize these materials typically require expensive and/or corrosive reagents and lead to the generation of significant waste streams. To overcome such issues, the Dong Research Group is developing environmentally sustainable approaches for the derivatization of ketones that enable direct access to a range of useful products using a combination of specially designed catalysts and simple olefins (inexpensive commodity chemicals). The broader impacts of the funded project extend to societal benefits accrued by the participation of Professor Dong and his coworkers in outreach activities, such as the "ChiS&E" program which provides early chemistry education to Chicago public middle-school students, and the Collegiate Scholars Program which allows for high school students to become involved in laboratory research. These activities will encourage a demographically diverse pool of young people, many of whom belong to groups underrepresented in science, technology, engineering, and mathematics (STEM) fields, to explore careers in science and engineering while learning and/or actively contributing to research. The goal of the funded research is to develop both alpha- and beta-selective ketone-olefin coupling reactions via transition metal-catalyzed C-H functionalization. To achieve the first process, Lewis acid/transition metal cooperative catalysis will be utilized to enable direct alpha-alkylation of the ketone substrates with simple olefins as coupling partners. To realize the second process, beta-alkylation of ketones, again by olefins, will be explored via a transition metal-catalyzed desaturation-based hydride-transfer strategy. An analogous process employing alkynes will likewise be pursued to achieve beta-alkenylation. The merits of these approaches are significant from both fundamental and practical standpoints, thus: (1) stoichiometric byproducts are potentially avoided; (2) the reaction conditions are generally pH- and redox-neutral, thereby tolerating a broad range of functional groups; and, (3) olefins are typically less expensive and more readily available feedstocks than the corresponding alkyl halides or organometallic species. Ultimately, it is anticipated that a suite of operationally convenient and environmentally sustainable carbonyl alkylation methods will emerge from these studies and that the findings will represent important advances to the fields of bifunctional and tandem catalysis. 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.