Email address: tyoon@chem.wisc.edu
Associate Professor
A.B. 1996, Harvard University
Ph.D. 2002, California Institute of Technology
Research Interests
The central theme of research in the Yoon group is the development of new catalytic methods for organic synthesis. We are most interested in reactions with the following features:
Visible Light Photocatalysis in Organic Synthesis
Sunlight is a safe, inexpensive, and endlessly renewable reagent. Most organic compounds, however, absorb light only at short wavelengths of ultraviolet light that are relatively poorly emitted in the solar spectrum. Conventional high-pressure UV photochemical reactions are thus rarely utilized on industrial scales, as they are energy-intensive, hard to scale, and relatively expensive. We are developing strategies to use transition metal photocatalysts in interesting new photochemical reactions that use visible wavelengths of light. By enabling the use of direct sunlight in synthetically useful reactions, we hope to pioneer a new, environmentally responsible approach to synthetic organic photochemistry.

New Reactions of Oxaziridines
A fundamental challenge in synthetic organic chemistry is the ability to add of oxygen- and nitrogen-containing functional groups to otherwise unfunctionalized hydrocarbon feedstocks (alkanes, alkenes, arenes) in a regioselective and stereoselective fashion. We are investigating the ability of three-membered heterocycles called oxaziridines to perform a wide variety of such oxidative functionalization reactions. We have developed methods to synthesize a range of structures, including 1,2-aminoalcohols, 1,3-aminoalcohols, isoxazolidines, piperidines, pyrrolidines, tetrahydroisoquinolines, and other structures that are commonly found in biologically active natural products and pharmaceutical agents.

Total Synthesis of Natural Products
The long-term goal of research in our group is the development of new methods for organic synthesis that can find broad applicability in the synthesis of complex molecular structures. The total synthesis of biologically active and architecturally interesting natural products represents the ultimate demonstration of the utility of new reactions and consequently constitutes a vital aspect of our research program. In addition, the challenges encountered in the course of a long multistep synthesis help to inform our approach to new reaction development.

| Amgen Young Investigator's Award | 2009 |
| UW-Madison Chancellor's Distinguished Teaching Award | 2013 |
| Eli Lilly Grant in Pharmaceutical Chemistry | 2010 |
| Fellow, Alfred P. Sloan Research Foundation | 2009 |
| Beckman Young Investigator Award, Arnold and Mable Beckman Foundation | 2008 |
| Photolysis, OH reactivity and ozone reactivity of a proxy for isoprene-derived hydroperoxyenals (HPALDs). Physical Chemistry Chemical Physics. 2012;14:7276-7286. |
| . Crossed intermolecular 2+2 cycloaddition of styrenes by visible light photocatalysis. Chemical Science. 2012;3:2807-2811. |
| . Visible light photocatalysis of intramolecular radical cation Diels-Alder cycloadditions. Tetrahedron Letters. 2012;53:3073-3076. |
| . Accessing the Synthetic Chemistry of Radical Ions. European Journal of Organic Chemistry. 2012;:3359-3372. |
| . Visible Light Photocatalysis of 2+2 Styrene Cycloadditions by Energy Transfer. Angewandte Chemie-International Edition. 2012;51:10329-10332. |