With this CAREER Award, the Chemistry Synthesis program is supporting the research of Professor Nan Zheng of the University of Arkansas. Nitrogen radical cations are synthetically useful yet underutilized electrophilic nitrogen sources. The goal of this project is to develop chemistry utilizing nitrogen radical cations generated under visible light photoredox conditions. There are three specific objectives. First, [3+2] annulation of cyclopropylanilines with alkynes, enynes, and diynes will be developed to provide 1-amino-2-cyclopentene derivatives. An asymmetric variant of the [3+2] annulation of cyclopropylanilines with alkynes will be investigated using a chiral Ru complex. Second, using much less reactive cyclobutylanilines, an analogous [4+2] annulation with alkynes, enynes, and diynes will be developed to synthesize 1-amino-2-cyclohexene derivatives. The [4+2] annulation method will be employed to complete a racemic synthesis of (±) hayayne. In the final objective, a general synthetic strategy based on a photocatalyzed cascade reaction will be developed for access to the akuammiline family of alkaloids.
Organic reactions driven by visible light are ideal for sustainable chemistry, as they use abundant sunlight, are operationally simple, and often have high atom economy. The chemistries in this project embody the principles of sustainable chemistry. The products of the reactions are highly useful synthetic intermediates for the pharmaceutical and materials industries. In addition, Professor Zheng will initiate three educational projects that interweave his research with teaching. The goals of these projects are to improve the learning experience of the students in organic chemistry courses and expose them to researches such as drug design and sustainable chemistry that are more interesting and relevant to them. The first project is to develop 3-D (three-dimensional) contents to improve how organic chemistry is taught. Some of the 3-D contents include using the Computation/Visualization Facility in the Center for Protein Structure in the Department of Chemistry and Biochemistry at the University of Arkansas to teach some basic concepts of drug design as well as using a 3D visualization system to help the students "see" stereochemistry better. The second educational project involves designing new experiments for advanced undergraduate organic labs and organic chemistry II labs based on the proposed research. The last educational project focuses on introducing sustainable chemistry to organic chemistry II lectures.
