Oxidative Coupling in Complexity Building Reactions

University Of Pennsylvania, Philadelphia PA

Investigators

Abstract

The Chemical Synthesis Program of the Chemistry Division supports the project by Professor Marisa Kozlowski of the Department of Chemistry at the University of Pennsylvania. She is developing new methods to couple molecular fragments into larger molecules. The chemistry allows for these larger molecules to be rapidly assembled in a manner that enables variations in their overall structure. This in turns allows for the study of how those variation alter the molecules properties. The molecules targeted for synthesis have a wide variety of potential applications ranging from their use as semiconductors with charge/energy transport properties for use in organic electronic devices and as liquid crystal materials to pharmaceutical applications in connection with the opium alkaloids. Much of the project lies at the interface of organic, computational, and materials chemistry. Therefore, the diversity of the science being pursued is well suited for the education of scientists at all levels. Broadening the participation of underrepresented populations in chemistry research is a particular focus of Professor Kozlowski with support for the Alliance for Diversity in Science and Engineering (ADSE) at Penn. The principal goals of this research program entail the development of oxidative methods for the coupling of fragments to generate more complex targets. Such routes introduce functionality at non-functionalized centers, thereby eliminating the need for complex pre-functionalized starting materials. The chemistry studied is contributing to environmentally benign methods for chemical synthesis by 1) engineering reactions at non-functionalized centers, thereby eliminating the need for complex pre-functionalized starting materials, 2) using oxygen is used as the terminal oxidizing agent, and 3) using less toxic and less expensive base metals. Transformations that are being pursued include oxidative phenol coupling to bring together three or more aromatic subunits, which are then oxidized further to provide polycyclic aromatic hydrocarbons with selective peripheral functionalization. Kinetic resolution is being explored with oxidative phenol coupling to create complex enantioenriched architectures, such as precursors to the opium alkaloids. Finally, oxidative coupling of the sp3 centers of alkyl arenes with a range of tertiary nucleophiles are being explored. Successful development of the methods is having a broad impact on a number of areas as there is a need to access such structures in the pharmaceutical, chemical, materials science, and agricultural industries as well as in basic biological and chemical research endeavors. The educational plan involves training high school students, undergraduate students, graduate students and postdoctoral researchers as well as outreach to foster inclusion of underrepresented communities into the chemistry research enterprise. 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.