================================================================제 목 : A Molecular Design Principle of Purely Organic PHotocatalysts for Visible-light Driven Polymerizations and Organic Reactions연 사 : 권민상 교수(UNIST 신소재공학부)일 시 : 2019년 4월 23일(화) 오후 4시 장 소 : 화학관 1층 첨단강의실(330118호실)================================================================A Molecular Design Principle of Purely Organic PHotocatalysts for Visible-light Driven Polymerizations and Organic Reactions Min Sang Kwon1Department of Materials Science and Engineering Ulsan National Institute of Science and Engineering (UNIST), Ulsan, Korea*E-mail: firstname.lastname@example.org The development of new chemical reactions using photoredox catalysts (PCs) is one of the most important topics in the field of organic and polymer synthesis since photoredox-mediated reactions are “green” and “mild” alternatives to thermal processes, and structurally unusual organic scaffolds can be built under extremely mild conditions using these catalysts. A variety of photoredox-mediated reactions have been actively developed in which organometallic complexes, including Ru(II) and Ir(III), have been mostly employed as PCs. However, concerns about toxicity, cost, precious-metal sustainability, and trace-metal contamination have limited their widespread use, especially in biomedical and electronic applications. In addition, the rather narrow redox-potential ranges and limited structural diversities of these transition-metal complexes limit their scope.Due to their broad structural diversity and benign environmental profiles, purely organic PCs provide attractive alternatives to transition-metal-based catalysts. However, the full potential of organic PCs has not been realized, as the criteria for their design are not well established. Therefore, the development of new transformations using organic PCs is limited to a few organic dyes commonly used for imaging purposes and whose parameters are not straightforwardly tuned through structural alternation.In this talk, we propose a general strategy for the design of purely organic PCs. Strongly twisted donor–acceptor structures are introduced as a general scaffold design for these PCs. The charge transfer (CT) characteristics of the lowest excited states of the designed PCs greatly promote the generation of the lowest triplet excited states (T1) and allow systematic control of the essential catalyst parameters over broad ranges, thereby facilitating efficient catalytic performance. Through combined computational and experimental studies, we provide a flow chart that facilitates the computationally directed rational design of organic PCs for the development of new photoredox-mediated reactions. Based on this strategy, highly efficient organic PCs were discovered that addressed important issues associated with photoredox-mediated atom transfer radical polymerization (ATRP), reversible addition-fragmentation chain transfer (RAFT), and dehalogenation reaction.  Singh, V. K., Yu, C., Badgujar, S., Kim, Y., Kwon, Y., Kim, D., Lee, J., Akhter, T., Thangavel, G., Park, L. S., Lee, J., Nandajan, P. C., Wannemacher, R., Milian-Medina, B., Luer, L, Kim, K. S.*, Gierschner, J.* & Kwon, M. S.*Nat. Catal.1, 794-804 (2018) “Highly efficient organic photocatalysts discovered via a computer-aided-design strategy for visible-light-driven atom transfer radical polymerization”
<Plenary Seminar>======================================연 사 : 강헌 교수님(서울대학교 화학과)제 목 : 얼음화학일 시 : 2019년 4월 4일(목) 오후 4시 15분 장 소 : 화학관 1층 첨단강의실(330118호)-------------------------------------- 지난 수 세기 동안 화학 연구는 액상의 물에서 진행되는 화학반응에 관심이 집중돼 온 반면, 얼음의 화학은 과학자들의 관심 밖이었다. 그 이유는 지구상에는 물이 얼음보다 많고 지구의 생태계는 물은 기반으로 이루어지기 때문이다. 또한, 온도가 낮은 고체상에서는 원자나 분자의 움직임이 매우 느리고 화학 반응도 일어나지 않는다는 것이 상식이었다. 하지만 우주 전체적으로 보면, 우주의 평균 온도는 대단히 낮고 대부분의 물 분자는 액체보다는 고체상의 얼음 형태로 존재한다. 따라서 우주에 떠다니는 차가운 얼음 입자에서도 끊임없이 원자와 분자가 만나 화학반응을 일으키고, 이렇게 오랜 시간에 걸쳐 생명의 기원에 필요한 분자들이 만들어져 왔을 것이라 과학자들은 상상한다. 본 세미나에서는 얼음에서 일어나는 미지의 화학 과정에 대한 연구를 간략히 소개한다. 실험실에서 고진공 표면 분광분석 장비를 사용하여 얼음 화학에 대한 어떠한 연구를 수행할 수 있으며, 얼음 화학의 지식이 저온 환경에서 일어나는 화학과정 및 우주의 얼음 입자에서의 분자 생성 과정을 밝히는 연구에 어떻게 활용될 수 있는지를 논의한다.
================================================================제 목 : Self-healing fiber-reinforced composite 연 사 : 이민욱 박사(KIST)일 시 : 2019년 3월 11일(월) 오후 4시 장 소 : 화학관 2층 서병인강의실(330226호실)================================================================A novel approach to enhancement of self-healing for chemical, mechanical damage, which is crucial to the life-time of composite materials is discussed. The key idea of the method is to encapsulating the healing agent within the core of polymer fibers. The experiments revealed that two parts of the healing agent (commercially available epoxy resin and hardener) are encapsulated in separate polymeric nanofibers. The fibers can be generated by a single-step dual coaxial nozzle or emulsion spinning via solution blowing or electrospinning. The core-shell fibers with the diameters in the 200-2600 nm range are encased in the PDMS (polydimethyl siloxane) matrix to form a self-healing composite material. Under fatigue conditions, the coreshell fibers inside the composite material are ruptured and the healing agents released into the surrounding matrix. Various fatigue conditions including repeated bending and stretching are used to damage the composites and the degree of self-healing is quantified after that. Also, an incision resembling a crack is pre-notched and crack propagation is studied. It is found that the presence of the self-healing agents in the fibers significantly retards crack propagation due to curing by the epoxy at the ruptured site. The stiffness of the composites is also measured for the samples containing self-healing fibers inside them before and after the fatigue tests. A novel theory of crack propagation is proposed, which explains the observed jump-like growth of subcritical cracks. Biography: Minwook Lee completed his BS and MS in Mechanical Engineering from Korea University in 2008 and 2010. He pursued his PhD studies at Korea University in the School of Mechanical Engineering (2014), followed by postdoctoral studies at University of Illinois at Chicago in the department of Mechanical and Industrial Engineering (2014.1-2017.3). In 2017 Dr. Lee has been appointed as senior researcher in Institute of Advanced Composite Materials at KIST (Korea Institute of Science and Technology). His research interests include theoretical and experimental fluid mechanics, heat and mass transfer, spray dynamics, numerical simulations of multiphase flows, fracture and recovering of polymer composite materials and multifunctional micro-/nanofiber, etc. His present h-index (Scopus, 1/2018) is 16, and Dr. Lee is the author of 40 research papers, 25 domestic/PCT patents.
====================================== 제 목 : FROM ORGANIC CHEMISTRY TO MOLECULAR IMAGING: FUTURECHEM 연 사 : 지대윤 교수님(서강대학교 화학과) 일 시 : 2018년 11월 8일(목) 오후 4시 15분 장 소 : 화학관 1층 첨단강의실(330118호) -------------------------------------- I. NEW FLUORINATION METHOD IN A NONPOLAR PROTIC ALCOHOL SOLVENTS The typical method for introducing fluorine, which is the best PET radioisotope, at a specific aliphatic molecular site is the nucleophilic displacement of the corresponding sulfonate or halide by fluoride ion. Ten years ago, we have developed a remarkable effect of using tertiary alcohols as a reaction medium for nucleophilic fluorination with alkali metal fluorides. The great efficacy of this method is a particular advantage in labeling radiopharmaceuticals with [18F]fluorine in high yield and purity, and in shorter times compared to conventional syntheses. In this new mechanism, the bulky, polarizable cation separates F- from the protic solvent, which in turn acts as a base to reduce the unfavorable influence of the cation on the nucleophilicity of F-. II. NEW PET RADIOPHARMACEUTICALS IN MARKET After FDG has been used since 1980s commercially, new F-18 labeled commercial PET radiopharmaceuticals have not been lunched until 2008. Using this new fluorination method, two new radiopharmaceuticals [18F]FLT (cell proliferation imaging) and [18F]FP-CIT3 (Parkinson disease) were registered at Korea FDA in 2008. For your information, [18F]FLT and [18F]FP-CIT are commercially used for patients at Korea after getting the official permission from Korean FDA in 2008 spring. In 2002, 11C-labeled [11C]PIB (Pittsburgh compound B) was developed for imaging Aβ plaque in the brain of living subjects by modifying Thioflavin T, which has been used as a fluorescent dye for staining Aβ plaque in postmortem brains. [11C]PIB exhibited good Aβ plaque binding in a living brain with an appropriate brain accumulation and washout ratio. Three F-18 labeled PET tracers have been approved by the U.S. Food and Drug Administration (FDA) in 2012 (AmyvidTM, Eli Lilly), 2013 (VizamylTM, GE Healthcare), and 2014 (NeuraceqTM, Piramal) as Aβ imaging agents and a secondary tool for the diagnosis of AD. We have also developed fourth F-18 labeled Aβ imaging PET tracer in NDA by Korean FDA in 2018 (Alzavue®, FutureChem). Prostate cancer imaging including some therapeutics will be discussed. III. DEVELOPEMNT OF NEW ORGANIC SYNTHESIS METHODOLOGIES Some new organic synthesis methodologies will be discussed.
======================================================================== 제 목 : Genome editing using CRISPR 연 사 : 배상수 교수님(한양대학교 화학과) 일 시 : 2018년 11월 1일(목) 오후 4시 30분 장 소 : 화학관 2층 서병인강의실(330226호실) =======================================================================Genome editing using CRISPR Sangsu Bae (email@example.com) Department of Chemistry, Hanyang University, Seoul 04763, South Korea Genome editing with engineered nucleases such as ZFNs (zinc finger nucleases), TALENs (transcription-activator-like effector nucleases), and CRISPR-Cas9/Cpf1 derived RNA-guided endonucleases is broadly used for biomedical research, biotechnology, and medicine. In addition, CRISPR base editors that enable the direct conversion of DNA bases without producing double-stranded breaks (DSBs) of DNA were developed. Unlike ZFNs and TALENs whose DNA specificities are determined by DNA-binding proteins, CRISPR nucleases use complementary base pairing to recognize target sites. Now, CRISPR nucleases are widely exploited due to the ease of use and inexpensive cost; researchers can induce gene editing at different sites by simply altering the guide RNAs. However, CRISPR nucleases cleave not only on-target sites but also off-target sites that differ by up to several nucleotides from the on-target sites, causing unwanted off-target mutations and chromosomal rearrangements. Here I present web-based programs, named CRISPR RGEN Tools (www.rgenome.net), including a novel CRISPR design tool and a genome editing assessment tool. These tools are indispensable for gene mutation in human cells, animals and plants. Furthermore, I would introduce versatile applications of CRISPR nucleases such as a one-step transformation of Chlamydomonas reinhardtii and petunia by the DNA-free CRISPR, a circulating tumor DNA detection and the detailed mechanism of Cas9/Cpf1 revealed by single-molecule fluorescence imaging. Ultimately, I would also introduce my on-going study – molecular cloning in human cells.
============================================================= 제 목 : Rh(III)-Catalyzed C-H Functionalization:Access to Novel Bioactive Molecules 연 사 : 김인수 교수님(성균관대학교 약학과) 일 시 : 2018년 10월 25일(목) 오후 4시 30분 장 소 : 화학관 2층 서병인강의실(330226호실) ============================================================== Rh(III)-Catalyzed C-H Functionalization: Access to Novel Bioactive Molecules In Su Kim School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea firstname.lastname@example.org With considerable progress in medicinal chemistry, the construction of heterocycles has receiveed increasing attention in the past decades. In particular, N-heterocycles are widely found to be biologically relevant scaffolds of natural products, pharmaceuticals, agrochemicals, and functional materials. In this context, the directing group-assisted N-heterocycle synthesis via C-H bond functionalization is highly attractive in pharmaceutical industry. Thus, we recently reported the construction of N-heterocycles via the Rh(III)-catalyzed C-H functionalization followed by intramolecular cyclization. Moreover, our group recently focused on the synthesis and biological evaluation of N-heterocycles such as xanthones, chromones, indoles, azaindoles, indolines, acridines, and indolidinones, and etc. We herein describe a brief summary of our recent works on the synthesis of 2-benzazepines,1 bridged bicycles,2 carbazoles,2 and 2-naphthols3 using Morita-Balyis-Hillman (MBH) adducts as novel C-H allylation sources under Rh(III) catalysis. Additionally, we present the unexpected reactivity and selectivity of phosphonium salts (Wittig reagents) on the reductive C2-alkylation of pyridine and quinoline N-oxides, leading C2-alkylated pyridines and quinolines.4 The ability to alkylate pyridines and quinolines is also important for their further development as pharmaceuticals and agrochemicals, and for other purposes. < References > “Synthesis of 2-Benzazepines from Benzylamines and MBH Adducts Under Rhodium(III) Catalysis via C(sp2)-H Functionalization” ACS Catal. 2018, 8, 742–746. “Reactivity of Morita-Baylis-Hillamn Adducts in C-H Functionalization of (Hetero)aryl Nitrones: Access to Bridged Cycles and Carbazoles” Org. Lett. 2018, 20, 4632–4636. “One-pot Synthesis of 2-Naphthols Using Nitrones and MBH Adducts via Decarboxylative N-O Bond Cleavage” Org. Chem. Front. 2018, 5, in press. (selected as Cover Page of OCF) \\ “Reductive C2-Alkylation of Pyridine- and Quinoline-N-Oxides Using Wittig Reagents” Angew. Chem., Int. Ed. 2018, 57, 12737–12740.
============================================================== 제 목 : Preparation of superhydrophobic/superoleophilic sponge and steel mesh for rapid oil/water separation 연 사 : Prof. Saeid Azizian(Bu-Ali Sina University) 일 시 : 2018년 8월 23일(목) 오후 4시 30분 장 소 : 화학관 2층 서병인강의실(330226호실) ============================================================== Preparation of superhydrophobic/superoleophilic sponge and steel mesh for rapid oil/water separation In recent years, with the development of economy and society the frequent occurrence of water pollution by oil spillages and organic-compounds leakages has caused severe environmental and ecological problems. Therefore, oil-water separation has been a global challenge. The traditional methods or materials for oil/water separation such as in situ burning, gravity separation, air flotation, bioremediation and adsorption usually showed low separation efficiency, poor separation selectivity, high energy consumption as well as high operational complexity. Recently, surfaces with superhydrophobic and superoleophilic wettability (with water contact angle greater than 150°) which achieved by constructing rough surfaces and modifying with low-surface energy materials have attracted great interesting in the field of filtration. Herein a facile method, for the preparation of highly hydrophobic and highly oleophilic sponge and steel mesh will be presented which can be successfully used for effective oil-spill cleanup and oil/water filtration.
============================================================== 제 목 : BoShinTang (Healthy Soup) and Ssam (Wrap): Teaching Strategies for Professors of Diverse Young Chemists 연 사 : 윤지윤 교수님(University of Texas Arlington) 일 시 : 2018년 6월 14일(목) 오후 4시 장 소 : 화학관 2층 서병인강의실(330226호실) ============================================================== BoShinTang (Healthy Soup) and Ssam (Wrap): Teaching Strategies for Professors of Diverse Young Chemists Abstract As student population grows more diverse in post-secondary institutions, it is facing greater challenges in delivering instruction that provides effective care of the diverse student population, which includes those who speak English as a second language. This presentation introduces two instructional strategies, “Inclusive and Flipped Classroom,” that is designed for professors of the diverse young chemists to address their needs with a variety of backgrounds, learningstyles, and abilities. For the Inclusive classroom, the audience will learn various instructional strategies with examples, especially for culturally-responsive instructions. For the flipped classroom, the audience will be provided by one case study using an asynchronous tool, “VoiceThread.” By using these new instructional approaches, the professors will be enable to create equal educational opportunities for and improve the academic attainment in Chemistry for their diverse young chemists. Also, these new approaches will increase the professors’ interests in multicultural education. By applying the needs of ethnically diverse students into teaching, professors enhance theirknowledge and understanding of other cultures. Therefore, this presentation will advance the quality of university education for diverse students and help them to achieve their degrees by building institutional capacity for preparing a professional workforce, broadening their participation in Chemistry, and fostering all the students to complete their degrees in higher education.
============================================================== 제 목 : Understanding of alumina surface properties and catalyst preparation 연 사 : 곽자훈 교수님(School of Energy and Chemical Engineering, UNIST) 일 시 : 2018년 5월 31일(목) 오후 4시 30분 장 소 : 화학관 2층 세미나실(330226호실) ============================================================== Understanding of alumina surface properties and catalyst preparation Ja Hun Kwak School of Energy and Chemical Engineering, UNIST (email@example.com) Alumina is one of the most important heterogeneous catalyst materials, and is mainly used as a support for catalytically active phases (metal and oxide) owing to its surface properties, such as high surface area and thermal stability. Al2O3-based catalysts have wide applications, ranging from petroleum chemistry to automobile emission control. In addition, alumina itself is a well-known acidic catalyst for alcohol dehydration reactions. In this presentation, I would like to show the recent results that the surface properties of alumina characterized using ethanol TPD and ethanol dehydration reactions. Based on these results, I suggest that the ethanol interaction as a general descriptor of alumina surfaces. And I also utilize these quantitative understanding of alumina surface properties for understanding how does the catalytic materials interact with alumina surfaces. These results will provide important guidelines for the synthesis and characterization of commercially important alumina-supported catalysts. Keywords: alumina surface, acid-base property, alcohol dehydration, ethanol-TPD, Pt on alumina
============================================================== 제 목 : Chemistry-oriented synthesis of drug scaffolds and chemo-centric target profiling of the scaffolds 연 사 : 김미현 교수님(가천대학교 약학과) 일 시 : 2018년 5월 10일(목) 오후 4시 30분장 소 : 화학관 2층 세미나실(330226호실) ============================================================== Chemistry-oriented synthesis of drug scaffolds and chemo-centric target profiling of the scaffolds Arramshetti Venkanna, Zakir Ullah, Sualiha Afzal, Kang Kim, andMi-hyun Kim* Department of Pharmacy, College of Pharmacy, Gachon University, Hambakmoeiro 191, Yeonsu-gu, Incheon, Republic of Korea Can researchers simultaneously consider academic interest and the integrated platform of ‘from bench to market, and from market to bench’ during their drug R&D process? For the purpose, which type of factors need to be considered? Among current feasible factors, chemists in drug R&D can choose structural novelty of drug for IP transfer. In the contrast to the factor, current dominant strategy of drug discovery is rational drug design against a determined novel target (disease, MOA, pathway, or protein) and the strategy can exclude structural novel compounds due to weak activity towards the target. However, regardless of the main strategy, chemists can wonder how to maximize the utility of their new compounds as like drug repositioning of a clinical drug in drug discovery. In my study, the drug discovery ‘from curiosity in chemical structure, itself of drug scaffold’ rather than ‘from a specific target’ was considered. As an example, synthetic methodology of a novel drug scaffold, anomeric N,N-diarylamino tetrahydropyran was developed through C(sp3)-H functionalized cross-dehydrogenative coupling of aminoalochol under non-metal condition (TEMPO/iodine, TEMPO/ trivalent iodine) with the mechanistic explanation. In sequence, to investigate the utility of the new scaffold, 2D & 3D similarity screening and chemo-centric molecular target prediction were conducted to propose plausible target profiling. The selected list of predicted target proteins was proved by the experimental assay. As another example, asymmetric catalyzed dearomatization will be added with closed information.