Efficient Synthetic Methods of N-Heterocyclic Compounds using Pyridinium Zwitterion

===================================================================================== 제  목 : Efficient Synthetic Methods of N-Heterocyclic Compounds using Pyridinium Zwitterion 연  사 : 유은정 교수(강원대학교) 일  시 : 2016년 6월 9일(목) 오후 4시 30분 장  소 : 화학관 세미나실 (330118호실) ===================================================================================== Efficient Synthetic Methods of N-Heterocyclic Compounds using Pyridinium Zwitterion Eun Jeong Yoo Department of Chemistry, Kangwon National University, Chuncheon 200-701, Korea E-mail:ejyoo@kangwon.ac.kr [m+n]-Dipolar cycloaddition is a powerful and widely used strategy for synthesizing heterocyclic compounds in a single operation without giving rise to byproducts. Among the known dipoles, azomethine ylide, consisting of an iminium ion adjacent to a carbanion, is an allyl anionic type 1,3-dipole that can be applied to construct N-heterocyclic compounds. However, most studies have mainly focused on [3+2]-dipolar cycloaddition using well-known 1,3-dipoles and 2p-dipolarophiles, while scarce attention has been focused on the development of new types of dipoles, such as 1,2-dipole, 1,4-dipole, and 1,5-dipole, for the formation of non-five-memberted heterocycles. In this presentation, [5+n]-dipolar cycloaddition, which is an extraordinary tool for formation of medium-sized N-heterocyclic compound, will be present. Air-stable pyridinium zwitterion is efficiently prepared via the rhodium-catalyzed reaction between pyridines and 1-sulfonyl-1,2,3-triazoles. This unprecedented pyridinium zwitterion are quite stable and exhibits different pattern of charge distribution in comparison with that of typical azomethine ylides. In addition, isolated zwitterions could be used as a 1,5-dipole for forming medium-sized heterocyclic compounds. Thermal [5+2]-dipolar cycloaddition of pyridinium zwitterions and dimethyl acetylenedicarboxylate (DMAD) successfully occurs to afford the seven-membered heterocycles with excellent yields. This breakthrough spurred the development of rhodium(II)-catalyzed three-component [5+2] cycloaddition reactions of pyridines, 1-sulfonyl-1,2,3-triazoles, and activated alkynes via the in situ generated 1,5-dipole; thus, a user-friendly and operationally simple strategy for systematic generation of the core structure of 1,4-diazepines was afforded. We will also discuss a new type of intermolecular rhodium(II)-catalyzed [5+3]-dipolar cycloaddition of pyridinum zwitterions and enol diazoacetates. This higher-order cycloaddition allows for the formation of an eight-membered heterocyclic skeleton, which is otherwise difficult to construct. The optimized dipolar cycloaddition occurs efficiently under mild conditions over a wide range of pyridinium zwitterions with high functional group tolerance. References Lee, D. J.; Ko, D.; Yoo, E. J.* “A Class of Rh(II)-Catalyzed Cycloaddition Reaction of Non-classical 1,5-Dipoles for Formation of Eight-Membered Heterocycles” Angew. Chem., Int. Ed. 2015, 54, 13715. Yoo, E. J.* “Azomethine Ylide: an Isolable 1,5-Dipole for Affecting [5+2] Cycloaddition Reaction” Synlett 2015, 26, 2189 (SYNPACTS, invited article). Lee, D. J.; Han, H. S.; Shin, J.; Yoo, E. J.* “Multicomponent [5+2] Cycloaddition Reaction for the Synthesis of 1,4-Diazepines: Isolation and Reactivity of Azomethine Ylides” J. Am. Chem. Soc. 2014, 136, 11606

• 2016-06-09
• 화학관 330118호

• POSTED DATE : 2016-06-03
• WRITER : 관리자
• HIT : 863

Microgels: Can we control their internal structure?

============================================================== 제  목 : Microgels: Can we control their internal structure? 연  사 : Prof.Imre Varga(Loránd Eötvös University, Budapest) 일  시 : 2016년 4월 19일(화) 오후 4시 30분 장  소 : 화학관 세미나실 (330118호실) ============================================================== Microgels: Can we control their internal structure? Imre Varga   Coordinator of the Marie Curie Initial Training Network NanoS3. Institute of Chemistry, Eötvös Loránd University, 1117 Budapest Pazmany s. 1/A, Hungary .   email: imo@chem.elte.hu   The synthesis and characterization of poly(N-isopropylacrylamide) - based multi-responsive microgel particles has attracted a significant interest in the last decade. They are considered as promising candidates in many applications ranging from heavy metal scavengers to diagnostic applications, and controlled drug delivery systems. However, the simple uniform structure of these particles presents a serious limitation in many respects e.g. resulting in limited colloid stability and loading and release characteristics. To meet the challenges of nanotechnology, there is compelling need to develop synthetic methods for controlling the internal structure of the nanogel beads.   I will provide a summary of our work related to the preparation, characterization and application of pNIPAm based microgel particles. I will present a novel approach for the synthesis of microgel beads with controlled internal structure. The method allows to control the radial distribution of co-monomers within the gel particles, thus facilitating the preparation of microgel beads e.g. with homogenous crosslink density distribution or with unique hydrophilic shells. The formed core/shell structures can be further utilized to create either hierarchical nanoparticles or 3D-structures. I will show a few examples for the formation of hierarchical structures based on either electrostatic or host/guest interactions.    

• 2016-04-19
• 화학관 330118호

• POSTED DATE : 2016-04-15
• WRITER : 관리자
• HIT : 883

4/15(Fri.) KANEKA International Symposium 2016 안내

4/15(Fri.) KANEKA International Symposium 2016 안내     저희 성균관대학교에서는 2010년 KANEKA(주)로부터 지원을 받아 KANEKA/SKKU Incubation Center를 설립하여 전자재료 관련 기술과제에 관한 공동연구를 진행해왔습니다.     센터 행사의 일환으로 올해도 오는 4월 15일(금) 오전 9시 30분부터 성균관대에서 제 6회 “KANEKA/SKKU Incubation Center International Symposium 2016”을 개최할 예정입니다. 첨부자료에서 보실 수 있는 바와 같이, 연사는 지금까지와 마찬가지로 각 분야에서 세계적인 활약을 하고 계시는 저명한 교수 및 연구자들입니다. 특히, 기조강연을 맡은 Wisconsin대학 유혁(Yu Hyuk)교수는 재미교포로 세계적인 업적을 세운 훌륭한 교수입니다.     특별히 사전 접수가 필요 없으며, 등록비도 없으므로 당일 행사장에 부담 없이 와 주시면 감사하겠습니다.   강연에 관한 자세한 사항은 첨부파일의 포스터 및 초록집을 참고하여 주십시오.     행사명 : KANEKA/SKKU Incubation Center International Symposium 2016 날짜 : 2016년 4월 15일 (금) 장소 : 자연과학캠퍼스 학술정보관 Auditorium(B1) 시간 : 오전 9시 30분 ~ 오후 5시   강연자 및 타이틀 Hyuk Yu (University of Wisconsin-Madison) “Evolutionary Directions of US Chemical Research”   Tomiki Ikeda (Chuo Univ.) “Photomobile Polymer Materials: Structures and Functions”   Changhoo Chun (Seoul National Univ.) “Artificial Lighting for Plant Production in Vertical Farming”   Junji Kido (Yamagata Univ.) “White OLEDs for Displays and General Lighting”   Yasuo Nakane (Mizuho Securities Ltd.) “Outlook on Flat Panel Display Industry, LCD or OLED?”   Taeghwan Hyeon (Seoul National Univ.) “Designed Chemical Synthesis and Assembly of Uniform-sized Nanoparticles for Medical   and Energy Applications”   Gi-Ra Yi (Sungkyunkwan Univ.) “High-Density DNA Brushes on Polymer Particles for Building Up Colloidal Superstructures”   Tsuyoshi Sekitani (Osaka Univ.)                 “Imperceptible Sheet-Type Sensors for Cyber–Physical Systems”      

• 2016-04-15
• 자연과학캠퍼스 학술정보관 Auditorium(B1)

• POSTED DATE : 2016-03-31
• WRITER : 관리자
• HIT : 969

“In vivo NMR to elucidate Brain Function“

2016 Spring/Summer Semester Plenary Seminar at SKKU Department of Chemistry   ====================================== 제  목 :  In vivo NMR to elucidate Brain Function 연  사 :  김성기 교수(Center for Neuroscience Imaging Research Institute for Basic Science, SKKU) 일  시 :  2016년 6월 2일(목) 오후 4시 15분    장  소 :  화학관 첨단강의실(330118호) --------------------------------------                                              In vivo NMR to elucidate Brain Function Seong-Gi Kim(seonggikim@skku.edu) Center for Neuroscience Imaging Research Institute for Basic Science Sungkyunkwan University  NMR has been extensively used in chemistry for determining molecular structures and dynamics.  When NMR is used as an imaging mode with gradient coils, it is referred to as magnetic resonance imaging, which is used for non-invasive diagnostics of diseases. In my research, MRI is used for determining brain function non-invasively by utilizing a change of paramagnetic deoxyhemoglobin.  In my talk, I will discuss basic idea of functional MRI, current research lines, and IBS center’s NMR facility.                                                                                            

• 2016-06-02
• 화학관 330118호

• POSTED DATE : 2016-06-03
• WRITER : 관리자
• HIT : 906

“Principles and Applications of Coherent Multidimensional Spectroscopy

 2016 Spring/Summer Semester Plenary Seminar at SKKU Department of Chemistry   ====================================== 제  목 :  Principles and Applications of Coherent Multidimensional Spectroscopy 연  사 :  조민행 교수(고려대학교) 일  시 :  2016년 5월 26일(목) 오후 4시 15분    장  소 :  화학관 첨단강의실(330118호) --------------------------------------                                                         

Principles and Applications of Coherent Multidimensional Spectroscopy

 

Minhaeng Cho

Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Korea University, Seoul 02841, Korea. Department of Chemistry, Korea University, Seoul 02841, Korea.   Multi-dimensional optical or vibrational spectroscopy is a special class of time domain nonlinear optical spectroscopy that employs multiple ultra-fast laser pulses to obtain information about the couplings between quantum states in a variety of molecular or condensed matter systems. Since these couplings are often sensitive to the detailed structural configuration of the active molecules and the overall dynamical system evolution including interactions with the local environment, a great deal of information can potentially be obtained. It is especially well suited to follow the evolution of quantum coherences in light initiated reactions, including photosynthesis, or as an exceptionally useful probe of protein dynamics in solution. In fact, as demonstrated over the years, a vast number of different experimental configurations are possible depending on the chosen pulse sequences, geometric arrangement and polarization and signal detection method. Hopefully, this talk imparts a sound conceptual basis that will enable the diligent researchers to understand the importance of this extensive and rapidly growing research field.      

• 2016-05-26
• 화학관 330118호

• POSTED DATE : 2016-05-18
• WRITER : 관리자
• HIT : 707

“Translational Research in the Development of Polymerization Catalysts“

2016 Spring/Summer Semester Plenary Seminar at SKKU Department of Chemistry    이분열 교수, 아주대학교 “Translational Research in the Development of Polymerization Catalysts“화학적 지식의 경제성 창출? 가능한가? 화학이 돈이다!    Place: Chemistry Bld. Rm 330118Time: 4:15~5:30 pm. =========================================================================================== Translational Research in the Development of Polymerization Catalysts (중합 촉매 개발을 통한 대학 개발 기술의 산업체 기술이전) Bun Yeoul Lee Department of Molecular Science and Technology, Ajou University, Suwon 443-749 Korea bunyeoul@ajou.ac.kr   1) Olefin polymerizations In our laboratory, more than 100 new titanium and zirconium complexes have been preapred for olefin polymerizations for the last two decades. Especailly, organolithium compounds have been actively utilized in the construction of those complexes. The representative complexes1 and 2 can be prepared in two steps in Kg-scale, which exhibit high activity, high 1-octene incorporation, and high molecular weight in the ethylene/1-octene copolymerizations. Complex 1 is currently used in industry (LG) for the production of polyolefin elastomers (~80,000 T/y) and eventually complex 2was licensed out to Lotte Chem in 2011 with affront fee 600,000,000 Won.   2) CO2/epoxide copolymerization A highly active catalyst (3) was discovered for the CO2/epoxide copolymerization. Complex 3 showed a high TON up to ~20000 and a high turnover frequency (TOF) of ~20000 h-1 that produced a strictly alternating copolymer with a high molecular weight (Mn) of up to 300000. The catalyst was licensed out to SK in 2008 with affront fee 600,000,000 Won. 3) New compostable polymers from CO2 High-molecular-weight poly(1,4-butylene carbonate-co-terephthalate)s were prepared by condensation copolymerizations of 1,4-butanediol, dimethyl carbonate, and dimethyl terephthalate, which shows the comparable thermal properties to the commercialized compostable polyesters such as PLA, PHA, PBAT, and PBSA. The polymers were licensed out to Lotte Chem in 2014 with affront fee 500,000,000 Won.          

• 2016-04-14
• 화학관 330118호

• POSTED DATE : 2016-04-12
• WRITER : 관리자
• HIT : 638

Evaluation of Trehalose Derivatives as Radiotracers Specific for Tuberculosis in Animal Models of Disease

제  목 : Evaluation of Trehalose Derivatives as Radiotracers Specific for Tuberculosis in Animal Models of Disease 연  사 : 이승서 교수님(University of Southampton) Evaluation of Trehalose Derivatives as Radiotracers Specific for Tuberculosis in Animal Models of Disease   We are developing PET radiotracers specific to Mycobacterium tuberculosis (Mtb). In evaluating new treatments, [18F]-2-fluoro-2-deoxyglucose (FDG) has been shown to be a useful tool, but it is not highly correlated with bacterial burden. We are evaluating trehalose radiotracers which may be covalently incorporated in vivo into the Mtb cell wall to give a PET signal directly correlated to bacterial burden rather than reporting on inflammation or other host response. We have designed several [18F]-labeled trehalose derivatives and are evaluating them in animal models of tuberculosis. Two of the probes, [18F]-6-fluoro-6-deoxytrehalose (6-FTre) and [18F]-epi-4-fluoro-4-deoxytrehalose (epi-4-FTre) are chemically synthesized in a method similar to [18F]-2-fluoro-2-deoxyglucose (FDG) from peracetylated precursors, and one probe, [18F]-2-fluoro-2-deoxytrehalose (2-FTre), is chemoenzymatically synthesized in a one-pot, three-enzyme cocktail from [18F]-FDG. All three were initially evaluated in Mtb-infected rabbits by acquiring PET/CT scans and blood and urine samples for metabolism analysis. The 2-FTre probe is also currently being evaluated in a non-human primate model of tuberculosis. In initial experiments in Mtb-infected rabbits, the 6-FTre probe was rapidly metabolized to [18F]-6-fluoro- 6-deoxyglucose. However, the epi-4-FTre was metabolically stable and did label lesions in the rabbit lung. A typical signal-to-noise for labeling was 2-3:1. The 2-FTre gave a slightly higher signal-to-noise and also appeared to give some differential labeling when compared to FDG. However, we saw potential probe metabolism and decided to change to a marmoset model of tuberculosis, which should express lower levels of trehalase than rabbits. The 2-FTre is currently under evaluation in a marmoset model of disease and appears to be labeling lesions selectively. No metabolism is observed in blood or urine of the marmosets. The trehalose derived probes are demonstrating uptake in PET scans at the site of Mtb lesions. This technology will allow us to selectively label Mtb infection and monitor treatment in animals on experimental drug regimens.      

• 2016-03-28
• 화학관 330118호

• POSTED DATE : 2016-03-21
• WRITER : 관리자
• HIT : 613

Pot Economy in Total Synthesis

안녕하세요. 다음주 화요일(3월 8일)에 Plenary Seminar가 진행됩니다.         참석 부탁드립니다. 감사합니다.        ====================================== 제  목 :  Pot Economy in Total Synthesis 연  사 :  Prof.Yujiro Hayashi(Department of Chemistry, Tohoku University, Japan) 일  시 :  2016년 3월 8일(화) 오후 4시 15분    장  소 :  화학관 첨단강의실(330118호) --------------------------------------                                                                                                                                              Pot Economy in Total Synthesis Yujiro HayashiDepartment, Tohoku University, JapanE-mail: yhayashi@m.tohoku.ac.jphttp://www.ykbsc.chem.tohoku.ac.jp One-pot operations are an effective method for both carrying out several transformations and forming several bonds in a single-pot, while at the same time cutting out several purifications, minimizing chemical waste generation, and saving time. Thus, a one-pot reaction can be not only efficient, but also green and environmentally friendly, and “pot-economy” should be considered in planning a synthesis.1 Organocatalyst is an effective catalyst to carry out several reactions in a same vessel. Our group2 and Jørgensen’s group3 independently discovered that diphenylprolinol silyl ether, which is easily synthesized from proline, is an effective organocatalyst in the reaction nvolving enamine and iminium ion as a reactive intermediate. We have been investigating the application of this catalyst to the one-pot synthesis of biologically active compounds. We have already reported three pot synthesis of (-)-oseltamivir, a neuraminidase inhibitor used in the treatment of human influenza, based on the diphenylprolinol silyl ether mediated Michael reaction of aldehyde and nitroalkene as a key step. Recently we have accomplished “one-pot” synthesis of (-)-oseltamivir without evaporation nor solvent exchange by the modification of the previous three pot synthesis.4 We further applied one-pot synthetic strategy to the total synthesis of prostaglandin E1methyl ester, and accomplished three “one-pot” synthesis of this biologically important molecule.5 Recently (S)-baclofen was synthesized via one-pot sequential reaction from the commercially available compounds.A recent progress in the one-pot synthesis will be described.

• 2016-03-08
• 화학관 330118호

• POSTED DATE : 2016-03-21
• WRITER : 관리자
• HIT : 638

2D based materials and their possible applications

제  목 : 2D based materials and their possible applications 연  사 : 이효영 교수님(성균관대학교) 일  시 : 2016년 3월 3일(목) 오후 4시 30분 장  소 : 화학관 세미나실 (330226호실)    

• 2016-03-03
• 화학관 330226호

• POSTED DATE : 2016-03-21
• WRITER : 관리자
• HIT : 651

[세미나공지] 12월 30일(수)

안녕하세요.   다음주 수요일(12월 30일) 세미나가 진행됩니다. 많은 참석 부탁드립니다.   감사합니다. ====================================== 제 목 : Developing a new ultrafast proving tool : challenging the chemical- and electronic dynamics of energy storage and solar cell systems 연 사 : 서현욱 박사 (Centre for Free-Electron Laser Science) 일 시 : 2015년 12월 30일 (수) 오전 11시 장 소 : 화학관 세미나실 (330226호실) -------------------------------------- Developing a new ultrafast proving tool : challenging the chemical- and electronic dynamics of energy storage and solar cell systems   Laser based VUV pulses produced via the High Harmonic Generation process (HHG) by table-top systems enabled access to VUV and soft X-ray photon energies in the laboratory. In addition, ultrashort pulse duration downs to the attosecond scale opened new possibilities in many scientific research fields of physics and chemistry. Here our newly developed HHG-driven time- and angle- resolved PES set-up will be presented. The new machine is based on an apertureless time-of-flight electron spectrometer and a femto-second table-top laser light source. The spectrometer is equipped with supplemental pumping ports to extend the operational pressure up to 10-4 mbar range.   Recently, we have studied the HHG from the gas-filled waveguide when using mixtures of two rare gases (Ar and Ne) as a nonlinear gas medium. The admixing of Ne into Ar gas can improve the generation yields of harmonics under slight phase mismatching conditions by a factor of 2. It is attributed to an improvement of the phase matching in the gas mixture. Together with our new experimental set-up, our new observation on the improved efficiency of HHG process by using two rare gas mixtures will be presented.

• 2015-12-30
• 화학관 330226호

• POSTED DATE : 2015-12-24
• WRITER : 관리자
• HIT : 774