|Speaker||Prof. Won-jin Chung|
|Date||Thu. 8 Jun. 2017|
|Venue||#633, Asan Hall, College of Science|
“Part 1. A Catalytic Enantioselective Glycolate Aldol Reaction
via Lewis Base Activation of Lewis Acids”
Part 1. A general, efficient, Lewis-base catalyzed enantioselective addition of glycolate-derived silyl ketene acetals to a wide range of aldehydes will be presented. Both syn- and anti-diastereomers are accessible without changing the catalyst or controlling the geometry of the silyl ketene acetal. Simple modification of the size of alkyl groups on the silyl ketene acetal is sufficient to reverse the stereochemical course of the addition. The observed diastereoselectivity and reactivity could be rationalized by the analysis of six open transition state structures with the aid of computational analysis.
“Part 2. A General Enantioselective Approach to
the Chemical Synthesis of the Chlorosulfolipids”
Part 2. A concise and general approach has been developed for the enantioselective synthesis of three structurally related chlorosulfolipids. Key advances include highly stereocontrolled additions to a,b-dichloroaldehydes, kinetic resolution of complex chlorinated vinyl epoxide intermediates, and Z-selective alkene cross metathesis of cis-vinyl epoxides. This strategy facilitated the synthesis of enantioenriched danicalipin A, mytilipin A, and malhamensilipin A in nine, eight, and eleven steps, respectively.
1. Chung, W.-j.; Carlson, J. S.; Vanderwal, C. D. J. Org. Chem. 2014, 79, 2226–2241.
2. Chung, W.-j.; Vanderwal, C. D. Acc. Chem. Res. 2014, 47, 718–728.
3. Chung, W.-j.; Carlson, J. S.; Bedke, D. K.; Vanderwal, C. D. Angew. Chem. Int. Ed. 2013, 52, 10052–10055.
4. Denmark, S. E.; Chung, W.-j. J. Org. Chem. 2008, 73, 4582–4595.
5. Denmark, S. E.; Chung, W.-j. Angew. Chem. Int. Ed. 2008, 47, 1890–1892.
Prof. Won-jin Chung
Department of Chemistry, GIST, Gwangju, Republic of Korea
|Notice||Fall semester 2017 Seminar Schedule||-||-|
|48||[January 24, 2018] Electro-Optic Organic THz Wave Sources||Prof. O-Pil Kwon(Ajou University)||January 24, 2018 (Wednesday)|
|47||[Thu. 30 Nov. 2017] Prof. Sunmin Ryu/Department of Chemistry, POSTECH, Pohang, South Korea||Prof. Sunmin Ryu||Thu. 30 Nov. 2017|
|46||[Thu. 23 Nov. 2017] Prof. Sung-Gon Kim/Department of Chemistry, Kyonggi University, Suwon, Korea||Prof. Sung-Gon Kim||Thu. 23 Nov. 2017|
|45||[November 14, 2017] Zero-Point Energy, Fluctuations, and Dissipation : A (Mostly) Quantum-Optical Perspective||Prof. Milonni, Peter||November 14, 2017|
|44||[Thu. 16 Nov. 2017] Prof. Hyungjun Kim/Department of Chemistry, and Graduate school of Energy, Environment, Water, and Sustainability (EEWS), KAIST, Daejeon, Korea||Prof. Hyungjun Kim||Thu. 16 Nov. 2017|
|43||[Fri. 30 Oct. 2017] Prof. Igor Rodin/Department of Chemistry, Moscow State University, Moscow, Russia||Prof. Igor Rodin||Fri. 30 Oct. 201|
|42||[October 31, 2017] New ways of vision: Protein structures in translational medicine and business development, my experience||Prof. Robert Huber(1988 Nobel Prize in Chemistry)||October 31, 2017|
|41||[Thu. 26 Oct. 2017] Dr. Jung-Nyoung Heo/Center for Medicinal Chemistry Research, Korea Research Institute of Chemical Technology, Daejeon, Korea||Dr. Jung-Nyoung Heo||Thu. 26 Oct. 2017|
|40||[October 25, 2017] Ultrafast electron microscopy: applications in chemical and materials sciences||Dr. Byung-Kuk Yoo||October 25, 2017|
|39||[Mon. 16 Oct. 2017] Prof. Kirk S. Schanze/Department of Chemistry, University of Texas at San Antonio, Texas, USA||Prof. Kirk S. Schanze||Mon. 16 Oct. 2017|
|38||[Fri. 13 Oct. 2017] Dr. J. Nathan Hohman/The Molecular Foundry, Lawrence Berkeley National Laboratory, California, USA||Dr. J. Nathan Hohman||Fri. 13 Oct. 2017|
|37||[Thu. 12 Oct. 2017] Student Host Colloquium : Versatile Dendrimer-Encapsulated Nanoparticles for Analytical Applications||Prof. Joohoon Kim||Thu. 12 Oct. 2017|
|36||[October 10, 2017] Novel Terahertz Spectroscopies||Director Mischa Bonn||Tue, October 10, 2017|
|35||[Thu. 28 Sep. 2017] Prof. Eunsung Lee/Department of Chemistry, POSTECH and Center for Self–assembly and Complexity, Institute for Basic Science (IBS), Pohang, Republic of Korea||Prof. Eunsung Lee||Thu. 28 Sep. 2017|
|34||[Thu. 14 Sep. 2017] Prof. Dokyoung Kim/Department of Anatomy and Neurobiology, Kyung Hee University, Seoul||Prof. Dokyoung Kim||Thu. 14 Sep. 2017|
|33||7th Jilin-Korea-Waseda Alliance Annual Symposium||-||August 17 ~ 19, 2017|
|32||[Wed. 5 July. 2017] Seminar is canceled!||-||-|
|31||[Fri. 16 Jun. 2017] Prof. Martin Thuo/Department of Materials Science and Engineering, Iowa State University, USA||Prof. Martin Thuo||Fri. 16 Jun. 2017|
|»||[Thu. 8 Jun. 2017] Prof. Won-jin Chung/Department of Chemistry, GIST, Gwangju, Republic of Korea||Prof. Won-jin Chung||Thu. 8 Jun. 2017|
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