Seminars 2019

Title:Functional Branched Polymers: Synthesis and Applications
Speaker:Associate Professor Nicolay V. Tsarevsky
Date:13th December 2019
Time:3.00pm to 4.30pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Associate Professor Goto Atsushi
Abstract:Branched polymers with functionalities placed at specific locations (e.g., as pendant groups, at the branching points, or the chain ends) are of interest in many fields: from coatings and adhesives to catalysis, to drug delivery and imaging. Various methodologies will be described for the synthesis of functional branched macromolecules and some materials applications will be highlighted.

 

Title:Why Was My Paper Rejected? – Publishing Tips from a Journal Editor
Speaker:Dr David Peralta
Date:11th December 2019
Time:10.30am to 12.00pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Assistant Professor Qiao Yuan
Abstract:Have you ever wondered why your last journal submission was directly rejected? Or how editors pick referees and conduct peer review? Or what exactly do editors and publishing houses do? In this talk, Dr. David Peralta, Editor-in-Chief of ChemMedChem (a Wiley-VCH and ChemPubSoc Europe journal) talks from his experience as a scientific editor and opens up the "black box" of science publishing. David will provide concrete tips on how to optimize your submissions for a better chance at peer review, as well as discuss how one can deal with rejected papers. Masters and PhD students, junior faculty, and professors working in any field of the natural/physical sciences, particularly biology, chemistry, biotech, pharmacy, pharmacology, medicine, environmental science, physics, and materials sciences, are invited to this seminar to get tips on how to improve their manuscripts and chances of getting published. This is also a great opportunity to learn about editorial work, which is an excellent career option for those with graduate degrees in the sciences.

 

Title:Biopolar Electrochemistry: A Powerful Tool for Fabrication of Functional Materials
Speaker:Associate Professor Shinsuke Inagi
Date:10th December 2019
Time:11.00am to 12.30pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Assistant Professor Soo Han Sen
Abstract:

Electrosynthesis is a powerful method for the synthesis of organic, inorganic and polymeric materials based on electron transfer-driven reactions at the substrate/electrode interface.1 The use of electricity for synthetic reactions without the need for hazardous chemical oxidants and reductants is recognized as a green and sustainable method. Other advantages include control of the reaction selectivity by tuning the electrode potentials. A different mode for driving electrochemical reactions has recently been proposed, in which bipolar electrodes (BPEs) are available as wireless electrodes that undergo anodic and cathodic reactions simultaneously. Bipolar electrochemistry is an old technology that has recently garnered renewed attention due to the interesting features of BPEs because (i) the wireless nature of a BPE is useful for sensors and material synthesis, (ii) the gradient potential distribution on BPEs is a powerful tool for the preparation of gradient surfaces and materials, and (iii) electrophoresis is available for effective electrolysis. Recent progress in bipolar electrochemistry for the electrosynthesis of functional materials is summarized.2 The wireless nature of BPEs was utilized for symmetry-breaking to produce anisotropic materials based on the site-selective modification of conductive objects by electrodeposition and electropolymerization. Potential gradients on a BPE interface have been successfully used as controllable templates to form molecular or polymeric gradient materials, which are potentially applicable for high throughput analytical equipment or as biomimetic materials. The electric field necessary to drive BPEs is also potentially useful to induce the directed migration of charged species. The synergetic effects of electrophoresis and electrolysis were also successfully demonstrated to obtain various functional materials. These features of bipolar electrochemistry and the various combinations of techniques have the potential to change the methodologies of material synthesis.

References 1. T. Fuchigami, M. Atobe, S. Inagi, Fundamentals and Applications of Organic Electrochemistry: Synthesis, Materials, Devices, Wiley, 2014. 2. N. Shida, Y. Zhou, S. Inagi, Acc. Chem. Res. 2019, 52, 2598.

 

Title:Photosensitized Lanthanide Doped Nanoparticles for Bio-analytical Applications
Speaker:Dr Clémence Cheignon
Date:4th December 2019
Time:11.00am to 12.30pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Professor Xing Bengang 
Abstract:

The fast advances in medical research lead to a need for a constant improvement of the diagnostic and imaging analytical tools. User friendly methods with increasing sensitivity and specificity are mandatory for the detection and quantification of biomarkers present at very low concentrations in complex matrices. In this field, lanthanide-based luminescent compounds are promising probes as their spectroscopic properties give rise to a long excited state lifetime and very high brightness.1 We have recently developed lanthanide nanoparticles exhibiting exceptional brightness after photosensitization by an appropriate antenna ligand2 and characterized by a very high photostability and low cytotoxicity.3 We now aim at using these ultrabright nanoparticles (UNPs) as luminescent probes for specific detection and quantification of a targeted biomolecule by time-resolved luminescence. A proof-of-concept has been illustrated on two biomarker-target systems, through the bio-functionalization of UNPs by the biomarker. First, UNPs functionalization by streptavidin and specific biotin recognition4 of this luminescent system have been verified by energy transfer experiments with a biotinylated dye. Then, immunostaining of epidermal growth factor receptor (EGFR) overexpressed on cell membrane of epidermoid A-431 cell lines has been realized with UNPs labeled with antibody Matuzumab.

References 1. Sy, M., Nonat, A., Hildebrandt, N. & Charbonnière, L. J. Lanthanide-based luminescence biolabelling. Chemical Communications 52, 5080–5095 (2016). 2. Goetz, J. et al. Ultrabright Lanthanide Nanoparticles. ChemPlusChem 81, 526–534 (2016). 3. Cardoso Dos Santos, M. et al. Autofluorescence-Free Live-Cell Imaging Using Terbium Nanoparticles. Bioconjugate Chemistry 29, 1327–1334 (2018). 4. Green, N. Avidin. 3. the Nature of the Biotin-Binding Site. Biochemical Journal 89, 599–609 (1963).

 

Title:Marcomolecular Syntheses by Photoinduced Radical and Cationic Polymerizations
Speaker:Professor Yusuf Yagci
Date:2nd December 2019
Time:11.00am to 12.30pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Associate Professor Goto Atsushi 
Abstract:

Photochemical reactions [1,2] are efficiently used in macromolecular synthesis, involving initiation, control of the reaction kinetics and molecular structures, functionalization, and decoration, etc. Synthesis of polymers by free radical, cationic, (Figure 1) and step-growth mechanisms [3] can be realized through photochemical processes. Recently, PET reactions are increasingly used in atom transfer radical polymerizations (ATRP) (Figure 1) [4, 5] and “Click reactions” 6, 7] allowing polymers to be formed with well-defined structures and functionalities providing several distinct advantages, including temporal and spatial controls, rapid and energy efficient activation. The process is based on photoredox reactions of copper catalysts under various radiation sources with or without various photoinitiators. Furthermore, specific applications such as block and graft copolymer formation, metal-polymer nanocomposites etc. will be covered as well. Quite recently, metal free photoinduced atom transfer radical polymerizations have been introduced based on the electron transfer reactions involving photoexcited sensitizer, amine and alkyl halide [8.10]. In the presentation, the mechanistic aspects of free radical and cationic [11] photo polymerizations under metal free conditions will be focused.

References [1] S. Dadashi-Silab, S. Doran, Y. Yagci, Chem. Rev. 2016, 116, 10212-10275 [2] Y. Yagci, S. Jockusch, N.J. Turro, Macromolecules, 2010, 43, 6245-6260 [3] E. Sarı, G. Yilmaz, S. Koyuncu, Y. Yagci, J. Am. Chem. Soc., 2018, 140, 40, 12728 [4] S. Dadashi-Silab, M. A. Tasdelen, Y. Yagci, J. Polym. Sci.Part A: Polym. Chem. 2014, 52, 2878-2888 [5] X. Pan, M. A. Tasdelen, J. Laun, T. Junkers, Y. Yagci, K. Matyjaszewski, Prog. Polym.Sci., 2016, 62, 73-125 [6] M. A. Tasdelen, G. Yilmaz, B. Iskin, Y. Yagci, Macromolecules, 2012, 45, 56-61 [7] M. A. Tasdelen, Y. Yagci, Angew. Chem. Int. Ed., 2013, 52, 5930-5938. [8] C. Kutahya, S. F. Aykac, G. Yilmaz, Y. Yagci, Polym. Chem., 2016, 7, 6094-6098 [9] S. Jockusch, Y. Yagci, Polym. Chem., 2016, 7, 6039-6043 [10] A. Allushi, S. Jockusch, G. Yilmaz, Y, Yagci, Macromolecules, 2016, 49, 7785-7792 [11] M. Ciftci, Y. Yoshikawa, Y. Yagci, Angew. Chem. Int. Ed., 2017, 56, 519-523

 

Title:Synthesis of 3,4-Fused Tricyclic Indoles Using Transition Metal Catalysis
Speaker:Professor Tetsuhiro Nemoto
Date:25th November 2019
Time:2.30pm to 4.00pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Associate Professor Naohiko Yoshikai
Abstract:

3,4-Fused tricyclic indole skeletons are found in various bioactive natural products and pharmaceuticals. Most of these molecules possess a functionalized medium-size ring bridging the C3 and C4 positions of the indole. This class of compounds is an attractive target in synthetic organic chemistry due to the ubiquity of the structural motif in bioactive molecules, as well as their characteristic structures. In this presentation, two-types of synthetic method of this structural motif based on Pd catalysis [1] and Pt catalysis [2] will be discussed. The developed Pd catalysis could be applied to the synthetic studies on Dragmacidin E.[3]

References: 1) S. Nakano, N. Inoue, Y. Hamada. T. Nemoto. Org. Lett. 2015, 17, 2622–2625 2) Y. Suzuki, Y. Tanaka, Y. Hamada, T. Nemoto, et al. Chem. Eur. J. 2016, 22, 4418–4421. 3) N. Inoue, S. Nakano, S. Harada, Y. Hamada, T. Nemoto. J. Org. Chem. 2017, 82, 2787–2793

 

Title:JANUS PNAs: Upgraded PNAs for Simultaneous Recognition of Two Complementary DNA/RNA Strands
Speaker:Professor Krishna Ganesh
Date:31st October 2019
Time:2.00pm to 3.30pm
Venue:MAS Executive Classroom 1
Host:Associate Professor Roderick Bates
Abstract:

DNA and RNA are naturally endowed with structural features for self-assembly through complementary base pairing, leading to a variety of structures ranging from hairpins, duplexes, triplexes to cruciform and tetraplexes etc. Several chemically modified analogues involving modification of sugar-phosphate backbone have been developed in context of antisense therapeutics. All these analogues can bind to complementary sequences via hydrogen bonding frombases, but only from one side of the backbone. Varieties of topological structures or objects (DNA nanotechnology and DNA origami) are created by engineering sequences to assume different shapes. We have embarked on new types of Peptide Nucleic Acids (PNA) analogues that are is endowed with backbones that can structurally accommodate nucleobases from its either face. Such designed PNAs, termed “Janus” PNAs have the potential to form programmable self-assemblies with complementary DNA, RNA, PNA and other DNA analogues. This presentation demonstrates our initial studies on the synthesis and complementation studies of Janus PNAs, biophysical characterization of ‘double” duplexes generated from Janus PNA and cDNA and the synergistic effects on the thermal stability of each of the duplexes. 

 

Title:Drug Discovery Using Automated Synthesizer & Flow Reactor and Its Social Effect in Japan
Speaker:Professor Takashi Takahashi
Date:29th October 2019
Time:2.30pm to 4.00pm
Venue:SPMS Research and Graduate Studies Conference Room
Host:Professor Chiba Shunsuke 
Abstract:

Automated synthesis and flow chemistry have attracted a great deal of attention in recent years because these process improve both the reproducibility and reliability of synthesis. Development of automated synthetic procedures and storage of relevant digital data allow anyone to reproduce the same results anytime and anywhere using the same apparatus and reagents. As a result, synthetic chemists can spend more time on advanced and challenging problems. Automated synthesis and flow chemistry often enhance the safety profile of the synthetic processes. Flow chemistry is effective for the hazardous reactions using toxic reagents or high pressure gases. Herein, we report the automated synthesis of taxol, enediyne, lewisX and ketopiperazine analogues and the flow synthesis of peptides and aliphatic aldehydes. We also would like to discuss the social effect in Japan using the lab-automation and digitalize.

 

Title:Mechanochemistry: Luminescence and Organic Synthesis
Speaker:Professor Hajime Ito
Date:18th October 2019
Time:11.00am to 12.30pm
Venue:SPMS Research and Graduate Studies Conference Room
Host:Professor Chiba Shunsuke 

 

Title:Total Synthesis of the Marine Ladder Polyether Gymnocin B
Speaker:Dr Satapanawat Sittihan
Date:17th October 2019
Time:11.00am to 12.30pm
Venue:SPMS Research and Graduate Studies Conference Room
Host:Associate Professor Naohiko Yoshikai
Abstract:

Isolated in 2005, gymnocin B is the second largest contiguous marine ladder polyether, comprising one THF, nine THPs, and five oxepanes. Herein, we report the first total synthesis of gymnocin B based on a twophase strategy. In Phase I, inspired by the proposed biosynthesis, four epoxide-opening cascades assemble 10 out of 15 cyclic ether rings making up the molecular core. In the subsequent Phase II, coalescence elevates the molecular complexity further by coupling of these subunits. As demonstrated by a 45-step longest-linearsequence synthesis of gymnocin B, our two-phase synthetic approach significantly improved the step efficiency of the synthesis of this class of natural products.

References 1. Satake, M.; Tanaka, Y.; Ishikura, Y.; Oshima, Y.; Naoki, H.; Yasumoto, T. Tetrahedron Lett. 2005, 46, 3537–3540. 2. Sittihan, S.; Jamison, T. F. J. Am. Chem. Soc. 2019, 141, 11239–11244.

 

Title:Escape from Noble Transition Metals
Speaker:Associate Professor Christophe Bour
Date:14th October 2019
Time:2.00pm to 3.30pm
Venue:SPMS Research and Graduate Studies Conference Room
Host:Assistant Professor Jason England 
Abstract:

The discovery of simple processes and reactions has always been one of the priorities of modern organic chemistry. It has a strong impact in diverse areas such as the elaboration of new drugs, production of materials with specific properties, sourcing and storage of energy... Over the last thirty years, the emergence of organotransition-metal chemistry has afforded a significant step forward. It still represents one of the most important chemical endeavors. The rush into this chemistry has slowed down the development of synthetic methods relying on main-group elements. Many of these processes rely on the use of complexes of late transition metals of the 2nd and 3rd rows (Pd, Ru, Rh, Ir, Pd, Pt, Ag, Au...). To circumvent the elevated cost of this rare elements and their toxicity, various strategies are conceivable. One is to use heterogeneous reusable complexes; however the lower investment in catalyst can be counterbalanced by a costly recovery step. Another way is to improve the efficiency of the process, so that only a trace amount of catalyst can be used. Lastly, a third option consists in replacing noble metals by abundant elements of biocompatible main-group compounds among which derivatives of s-block or p-block metals can be efficient surrogates. In that respect, we explored these two last strategies and we disclosed that well-defined first row transition metal as well as Group 13 metals or calcium derivatives could be used as catalysts for C-C and C-N bonds formations.

References: 1. M. Pareek, C. Bour, V. Gandon, Org. Lett., 2018, 20, 6957. 2. Vayer, M.; Morcillo, S.; Dupont. J.; Gandon, V.; Bour, C. Angew. Chem. Int. Ed. 2018, 57, 3228. 3. Li, Z.; Thiery, G.; Lichtenthaler, M.; Krossing, I.; Guillot, R.; Gandon, V.; Bour, C. Adv. Synth. Cat. 2018, 3, 544. 4. Morcillo, S. P.; Lebœuf, D.; Bour, C.; Gandon, V. Chem. Eur. J. 2016. 22, 16974. 5. Michelet, B.; Tang, S.; Thiery, G.; Monot, J.; Li, H.; Guillot, R.; Bour, C.; Gandon, V. Org. Chem. Front. 2016, 3, 1603

 

Title:Asymmetric Hydrogenation Using Chiral Tridentate Ligands
Speaker:Professor Zhang Xumu
Date:3rd October 2019
Time:11.00am – 12.30pm
Venue:SPMS Research and Graduate Studies Conference Room
Host:Associate Professor Naohiko Yoshikai
Abstract:

Catalytic asymmetric hydrogenation of prochiral ketones is a convenient and economical method to prepare chiral alcohols, which are significant building blocks in pharmaceuticals and natural products. Since Noyori’s milestone work in the 1990s wherein the BINAP-ruthenium-diamine catalytic system was originally developed for hydrogenation of ketones, numerous ligands including bidentate and tridentate ligands have been synthesized and investigated in metal catalyzed asymmetric hydrogenation. Because of the stability and high activity, tridentate ligands have shown promising potential in ketone reduction. In 1998, we had developed a novel tridendate NNN ligand (ambox) which had been successfully used in asymmetric transfer hydrogenation of ketones, which represents the first application of a tridendate ligand in asymmetric (transfer) hydrogenation.[1] Since then, chiral tridendate ligands have attracted increasing attention in highly efficient and enantioselective ketone hydrogenation. In 2010, indan-ambox, a derivative of ambox, had been applied in asymmetric hydrogenation of ketones with excellent enantiocontrol albeit with low efficiency.[2] To solve the efficiency problem, our group has recently developed a series of ferrocene-based tridentate ligands, f-amphox, [3] f-amphol, [4] f-ampha, [5] and famphamide, [6] which had shown super activity in iridium-catalyzed asymmetric hydrogenation of ketones (TONs up to 1 000 000). Compared to Noyori’s BINAP-ruthenium-diamine catalytic system, iridium (III)-hydride complex ligated with theses tridentate ligands have several features, including (1) extreme stability because of d6 configuration of Ir (III); (2) extreme activity because of the two Ir-H trans effect; (3) devoid of product inhibition due to coordinative saturation.

References [1] Jiang, Y.; Jiang, Q.; Zhang, X. J. Am. Chem. Soc. 1998, 120, 3817. [2] Li, W.; Hou, G.; Wang, C.; Jiang, Y.; Zhang, X. Chem. Commun., 2010, 46, 3979. [3] Wu, W.; Liu, S.; Duan, M.; Tan, X.; Chen, C.; Xie, Y.; Lan, Y.; Dong, X.-Q.; Zhang, X. Org. Lett. 2016, 18, 2938. [4] Yu, J.; Jiao, L.; Yang, Y.; Wu, W.; Xue, P.; Chung, L. W.; Dong, X.-Q.; Zhang, X. Org. Lett. 2017, 19, 690. [5] Yu, J.; Duan, M.; Wu, W.; Qi, X.; Xue, P.; Lan, Y.; Dong, X.-Q.; Zhang, X. Chem. Eur. J. 2017, 23, 970. [6] Liang, Z.; Yang, T.; Gu, G.; Dang, L.; Zhang, X. Chin. J. Chem. 2018, 36, 851.

 

Title:Solid-state NMR Study on the Acidity of Heterogeneous Catalysts and Catalytic Reaction Mechanisms
Speaker:Professor He Heyong
Date:1st October 2019
Time:2.00pm to 3.30pm
Venue:SPMS Research and Graduate Studies Conference Room
Host:Associate Professor Goto Atsushi
Abstract:

Solid-state NMR spectroscopy is a unique technique in the study of catalytic reaction mechanisms with its advantage of quantitative information. We successfully used the controlled atmosphere MAS NMR technique with 13C labeled reactant to study the reaction mechanism of n-butane isomerisation over a number of solid acid catalysts, including sulfated zirconia and tungstophosphoric acid-based catalysts. The results show that the increase of the Brönsted acid strength rather than acid density is important to enhance the catalytic activity, which provides useful information on the design of relevant catalysts. Also, we explored a new way to study the acidity and basicity of metal oxide catalysts using basic and acidic probe molecules simultaneously with the NMR technique. Compared to the normal single probe molecule method, the acidity obtained with our new method is more fitting for the catalytic performance of acetone self-condensation reaction over metal oxide catalysts.

 

Title:Hexafluoroisopropanol : A Solvent of Choice for Challenging Transformation
Speaker:Dr David Leboeuf
Date:27th September 2019
Time:11.00am to 12.30pm
Venue:SPMS Research and Graduate Studies Conference Room
Host:Associate Professor Leong Weng Kee/ Hélène Bertrand
Abstract:

Today, there is a strong demand from the fine chemicals industry to develop procedures based on transition metalsfree reactions using readily available starting materials. The main reasons behind this are the availability, cost and toxicity of transition-metals or electrophiles. In that respect, employing simple alcohols and alkenes for C-C bond forming reactions is truly appealing, but it can remain challenging, notably when the substrates are highly deactivated or prone to sequester the catalyst. Recently, we have demonstrated that the acidity of hexafluoroisopropanol (HFIP) could be significantly harnessed by calcium(II) salts in order to activate C-O and C-C bonds, outperforming common Lewis and Brønsted acids in terms of activity and efficiency in several reactions through the coordination of HFIP to calcium and the formation of H-bond clusters. Moreover, due its strong H-bond donor ability, HFIP has the capacity to facilitate the release of Lewis acids trapped by unwanted coordination to the substrate (or the product), allowing the catalytic process to turn over. In particular, the combination Ca2+/HFIP can be a powerful tool to promote electrocyclizations, hydroaminations, hydroarylations and hydroacyloxylations. These reactions proved to be general and compatible with a wider range of substrates than the traditional catalytic systems.

 

Title:The Development of New Fluorination Reagents and Reactions by Probing the Unique Fluorine Effects
Speaker:Professor Hu Jinbo
Date:24th September 2019
Time:1.00pm to 2.30pm
Venue:SPMS Research and Graduate Studies Conference Room
Host:Professor Chiba Shunsuke

 

Title:Terahertz Molecular Science in the Condensed Phases
Speaker:Professor Keisuke Tominaga
Date:23rd September 2019
Time:2.30pm – 4.00pm
Venue:SPMS Research and Graduate Studies Conference Room
Host:Associate Professor Loh Zhi Heng
Abstract:

There has been considerable interest in both the experimental and theoretical investigation of the lowfrequency motion associated with molecules and molecular aggregates in condensed phases. Dramatic progress has been made in the generation and detection techniques of freely propagating THz radiation based on femtosecond pulsed laser in the past two decades. Because the pulse duration of the THz radiation is in a sub-picosecond time region, it is possible to measure the electric field of the radiation by coherent detection methods, which consequently allows us to conduct THz time-domain spectroscopy (TDS). By THz-TDS we can obtain the refractive index and extinction coefficient of a medium by measuring the phase and amplitude of the THz radiation. THz-TDS is an attractive method for studying dynamics in condensed phases with time scales of sub-picoseconds and picoseconds. In this talk I summarize our recent activities on the application of pulsed THz radiation spectroscopy to condensed phases such as biomolecules, solutions, and liquids. Furthermore, I will briefly mention the optical-pump THz-probe spectroscopy for organic semiconductor thin films to observe charge carrier dynamics created by optical excitation

 

Title:Ultrafast Excited State Dynamics of Twisted Aromatics
Speaker:Professor Mahesh Hariharan
Date:20th September 2019
Time:2.30pm – 4.00pm
Venue:SPMS Research and Graduate Studies Conference Room
Host:Associate Professor Edwin Yeow
Abstract:

Self-assembling of organic chromophoric systems into elegant supramolecular architectures with emergent properties has received prodigious attention in recent years.1 The notion of ‘emergence upon assembly’ is evidenced in the unusual photoexcited state dynamics exhibited by chromophoric assemblies. In the first example, a naphthalenenaphthalimide donor-acceptor (D-A) dyad assembled into segregated D-A stacks in the crystalline state. The photoinduced charge separated state in the aggregate state lasts 10,000 times longer than the monomeric dyad. The femtosecond transient absorption spectra depicted the spectroscopic signature for naphthalene dimer radical cation indicating the migration of charges through the stacks.2 In the second example, we report the crystalline evidence for Greek cross‐dipole (α=90°) stacking of 1,7‐dibromoperylene‐3,4,9,10‐tetracarboxylic tetrabutylester (PTE‐Br2 ) displaying null excitonic coupling and thereby monomeric optical behavior. Additionally, the semi‐classical Marcus theory of charge‐transfer rates predicted a selective hole transport phenomenon in the orthogonally stacked PTE‐Br2 . 3 In the third example, we showcase a radial assembly of 1,8-dibromonaphthalene(2,6-diisopropylphenyl)imide (NIBr2 ) in crystalline phase driven by hexabromine synthon.4NIBr2 exhibits ultrafast intersystem crossing5 and solid-state room temperature phosphorescence. We believe the fundamental understanding of noncovalent interactions dictating the unorthodox assembly of chromophores6 and probing of emergent properties are paramount for the rational design and construction of robust functional materials.

References: 1. Cheriya, R. T.; Mallia, A. R.; Hariharan, M. Energy Environ. Sci. 2014, 7, 1661. 2. Mallia, A. R.; Salini, P. S.; Hariharan, M. J. Am. Chem. Soc. 2015, 137, 50, 15604. 3. Sebastian, E.; Philip, A. M.; Benny, A.; Hariharan, M. Angew. Chem., Int. Ed. 2018, 57, 15696. 4. Niyas, M. A.; Ramakrishnan, R.; Vijay, V.; Sebastian, E.; Hariharan, M. J. Am. Chem. Soc. 2019, 141, 4536. 5. Nagarajan, K.; Mallia, A. R.; Muraleedharan, K.; Hariharan, M. Chem. Sci. 2017, 8, 1776. 6. Ramakrishnan, R.; Niyas, M. A.; Lijina, M. P.; Hariharan, M. Acc. Chem. Res. 2019, 52, ASAP

 

Title:Bioinspired Ultra-repellent Surfaces and How to Characterize Them
Speaker:Dr Dan Daniel
Date:12th September 2019
Time:2.00pm to 3.30pm
Venue:SPMS Research and Graduate Studies Conference Room
Host:Associate Professor Ling Xing Yi
Abstract:

In nature, the need to repel liquid contaminants can be a matter of life and death. For example, insects must avoid getting trapped by falling raindrops and plants need to keep their leaves dry for efficient gas exchange through the stomata. It is not surprising therefore that many state-of-the-art liquid-repellent surfaces have been inspired by examples in nature. In this talk, I will discuss two classes of ultra-repellent surfaces inpired by the lotus leaf and the cartilage surface, as well as new ultra-sensitive techniques we developed to characterize their wetting properties. Using a custom-built setup and a modified AFM technique, we are able to map micron-scale wetting variations on surfaces and measure the forces experienced by a moving droplet down to the pN level. The ultra-sensitive nature of our technique will ultimately allow us to probe the intermolecular forces that ultimately give rise to the wetting properties observed – an important information that will help us design better surfaces at the molecular level.

 

Title:Controlled Drug Delivery with Biodegradable Nanoparticles- Paradigm Shift in Therapeutics
Speaker:Professor Balasubramanian Sengottuvelan
Date:12th September 2019
Time:11.00am to 12.30pm
Venue:SPMS Research and Graduate Studies Conference Room
Host:Associate Professor Roderick Bates
Abstract:

The delivery of drug molecule to the affected site is as important as discovery of new molecules for the treatment of diseases. Drug can ideally exhibit its pharmacological activity only at the specific site to which the drug is delivered by a carrier. A range of drug delivery systems (DDS) and drug targeting systems have been developed to minimize drug degradation and loss, to prevent harmful side effects and to increase drug bioavailability and the fraction of the drug accumulated in the required zone. Controlled drug delivery occurs when a polymer, natural or synthetic, is judiciously combined with a drug in such a way that it is released from the carrier in a predesigned manner. The purpose behind controlling the drug delivery is to achieve more effective therapies while eliminating the potential for both under and overdosing. DDS has benefitted tens of millions of patients by relieving suffering and prolonging life in which the therapeutic efficacy of the drug has been improved. The synthesis of biodegradable of diblock , triblock and multi block copolymers and the encapsulation of drug molecules( anti TB and anti cancer) in the polymeric nanoparticles and their characterization by spectral, microscopic and thermal studies as well as their drug uptake and release behavior will be discussed. The encapsulation of both hydrophobic and hydrophilic drugs in the same polymer matrix as well as the minimization of drug-drug interaction on storage will be highlighted. The application of metal nanoparticles in controlled drug delivery will also be presented.

 

Title:Molecular-level Description of Excitation Energy Transfer in light-harvesting Systems
Speaker:Professor Ulrich Kleinekathofer
Date:28th August 2019
Time:10.30am to 12.00pm
Venue:SPMS Research and Graduate Studies Conference Room
Host:Associate Professor Tan Howe Siang

 

Title:Two-dimensional Electronic Spectroscopy of Molecular Aggregates: When Theory Meets Experiments
Speaker:Associate Professor Cheng Yuan-Chung
Date:21st August 2019
Time:10.30am to 12.00pm
Venue:SPMS Research and Graduate Studies Conference Room
Host:Associate Professor Tan Howe Siang

 

Title:Sketch and Peel Lithography for Multiscale Patterning
Speaker:Professor Duan Huigao
Date:16th August 2019
Time:2.00pm – 3.30pm
Venue:MAS Executive Classroom 1
Host:Associate Professor Ling Xing Yi
Abstract:

Reliable multiscale patterning across nanometer to millimeter scale is of great importance but challenging for various applications. In this presentation, I will first share a unique multiscale patterning process called “sketch and peel” lithography. The process is based on electron or ion-beam lithography, but it allows much higher patterning throughput with enhanced resolution for multiscale features compared to conventional processes. The applications of this unique process for transfer printing and flexible & stretchable devices will also be summarized. During the talk, a brief introduction to our work on other extreme micro/nanomanufacturing approaches and relevant applications will also be given.

 

Title:A Step Beyond the Boundary of Traditional Aryne Chemistry
Speaker:Associate Professor Li Yang
Date:16th August 2019
Time:11.00am to 12.30pm
Venue:SPMS Graduate and Research Conference Room
Host:Associate Professor Naohiko Yoshikai
Abstract:

Polysubstituted arene structural motifs broadly exist in numerous natural products, drug molecules, and organic functional materials. How to quickly construct them continues to be one of the themes in organic chemistry. Although traditional benzyne intermediate can readily assemble vicinal difunctionalized arenes, it has been restricted to accomplish multifunctionalization with this highly active species. Our research focuses on the ways to break the limitation of traditional arene chemistry, which could be achieved via either 1,2-benzdiyne (namely domino aryne) chemistry or cascade simple aryne reaction/C-H functionalization. Meanwhile, we are interested in the discovery of new research maneuvers in aryne chemistry. Along with the development of our aryne multifunctionalization systems, several drug molecules could be prepared as well.

References: 1. Qiu, D.; Shi, J.; Guo, Q.; Xu, Q.; Li, B.; Li, Y.* J. Am. Chem. Soc. 2018, 140, 13214-13218. 2. Xu, H.; He, J.; Shi, J.; Tan, L.; Qiu, D.; Luo, X.; Li, Y.* J. Am. Chem. Soc. 2018, 140, 3555-3559. 3. Lv, C.; Wan, C.; Liu, S.; Lan, Y.;* Li, Y.* Org. Lett. 2018, 20, 1919-1923. 4. Shi, J.; Li, Y.; Li, Y.* Chem. Soc. Rev. 2017, 46, 1707-1719. 5. Shi, J.; Xu, H.; Qiu, D.; He, J.; Li, Y.* J. Am. Chem. Soc. 2017, 139, 623-626. 6. Li, Y.; Qiu, D.; Gu, R.; Wang, J.; Shi, J.; Li, Y.* J. Am. Chem. Soc. 2016, 138, 10814-10817. 7. Li, L.; Qiu, D.; Shi, J.; Li, Y.* Org. Lett. 2016, 18, 3726-3729. 8. Qiu, D.; He, J.; Yue, X.; Shi, J.; Li, Y.* Org. Lett. 2016, 18, 3130-3133. 9. Shi, J.; Qiu, D.; Wang, J.; Xu, H.; Li, Y.* J. Am. Chem. Soc. 2015, 137, 5670-5673.

 

Title:Silylcations and Novel Aromatics
Speaker:Professor Jay S. Siegel
Date:1st August 2019
Time:11.00am to 12.30pm
Venue:SPMS Graduate and Research Conference Room
Host:Assistant Professor Mihaiela Stuparu
Abstract:

The talk will cover our design of a system for characterizing silyl cations as super Lewis Acids and their development as catalysts for a "Friedel-Crafts” aryl coupling reaction involving C-F bond activation.

 

Title:Gas Phase Kinetics and Spectroscopy Relevant to Atmospheric and Combustion Processes
Speaker:Professor Raja Kumar Balla
Date:18th July 2019
Time:11.00am to 12.30pm
Venue:SPMS Graduate and Research Conference Room
Host:Associate Professor Richard Webster
Abstract:

Measurement of kinetic parameters is a challenging task, especially when the reactions take place in the timescales of micro to femtoseconds. Conventional tools may not be of great use, given the criticality of the situation. Reactions between radicals and stable molecules, radicals and radicals are extremely difficult to carry out and measure the kinetics. Usually, kinetics are studied by measuring the concentration of one of the species involved in the reaction with respect to the time under given parameters such as temperature pressure etc., in conventional methods. The comfort of measuring the concentrations will be missing, when one wants to measure the kinetics between radicals. In such events, measurement of a physical property of one of the reactant is of a good choice, which can be used indirectly to measure the concentration of the species under investigation. The properties such as fluorescence or induced fluorescence can be measured using advanced spectroscopic tools. Now-a-days, the spectroscopic tools are supersensitive and can be used to measure a species with concentrations in the range of parts per million to trillion, which means with a variation of six orders of magnitude with excellent signal to noise ratios.

In the present talk, the ultra-super sensitive and unique technique called Cavity Ring Down Spectroscopy (CRDS) will be introduced and the measurement of kinetics where radicals are involved will be demonstrated. In this technique, the effective optical path length is increased to a minimum of 20 km in a one meter Fabry Perrot cavity makes the technique ultra-super sensitive. The applications of CRDS will be demonstrated in the present talk. In addition, measurement of kinetic parameters using Laser Induced Fluorescence (LIF) and relative rate methods will be presented. Measurement of kinetic parameters at elevated temperatures relevant to combustion behind the shock waves will also be presented. Overall, this talk will give a very detailed and broad idea to the audience about the laboratory measurements of kinetic parameters of the reactions relevant to the atmospheric and combustion.

 

Title:Clean Processes of Polymerization: Organocatalysis, Photopolymerization, Biobased Monomers, Supercritical Carbon Dioxide, Water
Speaker:Dr Patrick Lacroix-Desmazes
Date:28th June 2019
Time:10.30 am to 11.30am
Venue:SPMS Graduate and Research Conference Room
Host:Associate Professor GOTO Atsushi
Abstract:

Pursuing efforts for the sustainable production of polymers, we have explored various methodologies to avoid the use of metal catalysts, petroleum-based reactants and organic solvents (volatile organic compounds VOCs). Photolatent polymerization opens the way for applications where a delayed reaction and/or a spatial control is required. The polymerization begins "on demand" when and where the irradiation is applied.[1-2] We will present photobase generators (PBGs) releasing either triazabicyclodecene (TBD) [3] or N-heterocyclic carbenes (NHC) as organocatalysts. Advantages and limitations of the two systems in terms of robustness and level of control in the ring-opening photopolymerization of monomers such as L-lactide will be highlighted. Besides, we will present the synthesis of star-shaped polymers based on epsilon-caprolactone by ringopening polymerization according to a core-first approach. To this aim, we have chosen to combine the utilization of a renewable initiator (D-sorbitol), a clean solvent (supercritical CO2 ), and an enzyme as catalyst (Candida antarctica lipase B). [4] In addition, amphiphilic star block copolymers were targeted for applications in aqueous media. Finally, we will present some results on aqueous radical emulsion polymerization of biobased monomers, starting form biosourced aromatic building blocks such as cardanol and eugenol. [5-6]

References: [1] Chem. Eur. J. 2018, 24, 337-341. http://dx.doi.org/10.1002/chem.201705145 [2] Polymer Chemistry 2018, 9, 5481-5498. http://dx.doi.org/10.1039/C8PY01011K [3] ACS MacroLetters 2018, 7, 688-692. http://dx.doi.org/10.1021/acsmacrolett.8b00251 [4] Polymer Chemistry 2018, 9, 5594-5607. http://dx.doi.org/10.1039/c8py01266k [5] Polymer Chemistry 2018, 9, 2468-2477. http://dx.doi.org/10.1039/c8py00167g [6] Green Chemistry 2019, Tutorial Review, 21, 36-53. http://dx.doi.org/10.1039/C8GC02277A

 

Title:Polyimide-based Composite Aerogels for Thermal Insulation and Flame Retardancy
Speaker:Dr Wei Fan
Date:27th June 2019
Time:3.00 pm to 4.30 pm
Venue:SPMS Graduate and Research Conference Room
Host:Associate Professor Ling Xing Yi
Abstract:

Due to their unique microstructure, aerogels show impressive properties, such as extremely high porosity, quite low apparent density, and considerably high surface area, which enable them to be attractive materials for applications in thermal insulating, chemical adsorbents, catalytic carriers, and electrical applications. Developing aerogels with controllable pores, outstanding mechanical properties and excellent thermal stability still remains a key challenge in evolution of aerogels. In this work, graphene reinforced polyimide (PI) composite aerogels were fabricated by an environmentally friendly freeze-drying technique followed by a thermal imidization process. The two-dimensional graphene oxide (GO) was simultaneously served as crosslinker, pore-tailoring agent, as well as reinforcing fillers. The asprepared PI/GO aerogel showed excellent mechanical and thermal insulation properties, with a highest specific modulus of 229.9 Mpa cm3 g -1 and lowest thermal conductivity of 28 mW m-1 K -1. Furthermore, graphene/montmorillonite (G/MMT) hybrid synergistically reinforced PI composite aerogels were fabricated for flame retardancy. Through the strong interaction between GO and MMT, GO/MMT hybrid can be synergistically dispersed in water, providing good dispersibility in PI matrix, thus endowing the composite aerogels with enhanced thermal and flame-retardant properties.

 

Title:Opening the Editor’s Black Box: Insider Tips for Successful Submissions
Speaker:Dr Claire M. Cobley
Date:27th June 2019
Time:2.00 pm to 3.00pm 
Venue:SPMS Graduate and Research Conference Room
Host:Professor Zhao Yanli

 

Title:Supramolecular Approach for New Targeted Cancer Therapy: From Assembly to Nanomedicine
Speaker:Professor Ja-Hyoung Ryu
Date:27th June 2019
Time:11.00 am to 12.30 pm
Venue:SPMS Graduate and Research Conference Room
Host:Associate Professor Xing Bengang
AbstractCancer is one of biggest disease worldwide, a huge threat of human. The endeavor efforts to cure the cancer have been developed from cytotoxic chemotherapy, targeted chemotherapy, to immunotherapy. However, the cytotoxic chemotherapy has severe side effects to kill healthy normal cells, and targeted chemotherapy which inhibits specific cancer proteins has drug resistance problem, and immunotherapy is only applicable for limited patient. Therefore, it is highly demanded to develop new paradigm of cancer therapy. Our research team has investigated new cancer therapy using supramolecular approach. In this talk, I would like to discuss about intra-mitochondrial assembly and supramolecularly protein-modified nanomedicine for targeted cancer therapy. In the first part, I will talk about the supramolecular polymerization of dipeptide inside the mitochondria. At the second part, I will talk about cancer-targeted nanomedicine to prevent the clearance of the particles by macrophages, while ensuring their targeting function in vitro and in vivo. These findings can provide a new insight into intra-mitochondrial assembly for the therapeutic approach and new targeting platform for the biomedical community since numerous functional proteins can be installed by the similar fashion.

 

Title:Porous-tectonics: The Total Synthesis of Advanced Porous Materials via Chemical Self-Assembly
Speaker:Professor Yusuke Yamauchi
Date:26th June 2019
Time:2.30 pm to 4.00pm
Venue:MAS Executive Classroom 1
Host:Associate Professor Ling Xing Yi
Abstract:Yamauchi’s group has been focused on design of novel nanocrystals and nanoporous materials toward various applications including batteries, fuel cells, solar cells, chemical sensors, field emitters, and photonic devices. Specifically, nanoporous metals with metallic frameworks can be produced by using surfactant-based synthesis with electrochemical methods. Owing to their metallic frameworks, nanoporous metals with high electroconductivity and high surface areas hold promise for a wide range of electrochemical applications. Furthermore, he has developed several approaches for orientation controls of tubular nanochannels. The macroscopic-scale controls of nanochannels are important for innovative applications such as molecular-scale devices and electrodes with enhanced diffusions of guest species. In this presentation, we will show our recent progress in new porous systems, “porous-tectonics”.

 

Title:Synthesis and Properties of Novel Cyclic π-Conjugated Molecules
Speaker:Professor Shigeru Yamago
Date:26th June 2019
Time:3.30 pm to 5.00 pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Professor Chiba Shunsuke
Abstract:Cyclic π-conjugated molecules have attracted significant attention due to their unique molecular structures, distinct properties, and potential application in materials science and technology. In particular, cycloparaphenylenes (CPPs), which possess the simplest cyclic structural unit of armchair carbon nanotubes have received considerable attention because of their availability by bottom-up organic synthesis. In this presentation, I will report on our endeavor for synthesizing novel cyclic π-conjugated molecules including CPP derivatives and their physical properties.

 

Title:Exploration of Synthesis and Property of Novel Porphyrinoids
Speaker:Professor Hiroshi Shinokubo
Date:26th June 2019
Time:2.00 pm to 3.30 pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Professor Chiba Shunsuke
Abstract:Norcorrole is a ring-contracted antiaromatic porphyrin, which lacks two meso-carbons from regular porphyrins. We have synthesized norcorrole Ni(II) complexes and investigated their properties, which are markedly different from conventional aromatic porphyrins. Recently, we have succeeded to prepare a closely stacked norcorrole dimer structure in solution. The antiaromaticity of the stacked norcorrole dimer was significantly reduced because of the emergence of three-dimensional aromaticity in the stacked antiaromatic π-systems.

 

Title:Microfluidics for Biochemical Analysis and Synthesis
Speaker:Chair Professor Xingyu Jiang
Date:26th June 2019
Time:11.00 am to 12.30 pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Associate Professor Xing Bengang
Abstract:

Microfluidics can be useful for synthesis and analysis of biochemicals. We demonstrate that microfluidics can dramatically improve the efficiency of these assays and screens. Driven by miniaturization and surface chemistry, microscale-chips allow the assays of clinically important biochemicals, with improved throughput, sensitivity and stability. Combined with nanoparticles and nano-materials, microfluidics show great promise in the synthesis and analysis of novel conjugates of biomolecules. For example, these platforms are also extraordinarily useful for the synthesis and analysis of therapeutics that can be potentially useful in the clinics, e.g., nanocarriers for introducing siRNA, CRISPR/Cas, and so forth.

Selected references: 1. Cao HY, Wang YY, Gao Y, Deng XL, Cong YL, Liu Y, Jiang XY, Angew Chem Int Ed, (2019), 1626-1631. 2. Yang MZ, Liu Y, Jiang XY, Chem Soc Rev, (2019), 850-884. 3. Xianyu YL, Wu J, Chen Y, Zheng W, Xie M, Jiang XY, Angew Chem Int Ed, 130, 7625-7639. (2018).M. Yang, Y. Chen, J. Yang, W. Zheng, X. Jiang,. Science Advances, DOI: 10.1126/sciadv.aao4862 (2017). 4. Cheng SY, Jin Y, Wang NX, Cao F, Zhang W, Bai W, Zheng WF, Jiang XY, Adv Mater, (2017). Article number: 1700171. 5. Lei YF, Tang LX, Xie YZY, Xianyu YL, Zhang LM, Wang P, Hamada Y, Jiang K, Zheng WF, Jiang XY, Nature Communications, DOI: 10.1038/ncomms15130. (2017) 6. Andersen AS, Zheng WF, Sutherland DS, Jiang XY, Lab Chip, 15, 4524-4532(2015). 7. Zhang L, Feng Q, Wang JL, Sun JS, Shi XH, Jiang XY. Angew Chem Int Ed, 54, 3952-3956. (2015)

 

Title:Scientific Writing & Publishing
Speaker:Dr Alison Stoddart
Date:25th June 2019
Time:11.00 am to 12.30 pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Professor Zhao Yanli

 

Title:Borametallomimetics – Activation of Small Molecules by Low-valent Boron Species
Speaker:Professor Holger Braunschweig
Date:14th June 2019
Time:2.00 pm to 3.30 pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Associate Professor Rei Kinjo
Abstract:

The activation of small molecules is generally associated with transition metals (TM) and constitutes the basis of catalysis. It was believed that TM catalysts are required to facilitate processes such as the activation of H2 and other unreactive substrates. However, recent years have witnessed exciting developments in main group element chemistry, and the discovery of carbenes, FLPs and heavy main group species that are capable of TM-like activation reactions.1 Our ongoing studies on borylenes, diborenes, and diborynes have shown that these low-valent species exhibit a very rich chemistry, which is distinctly different from that of common compounds deriving from boron in oxidation state +3. Particularly interesting is the metal-like behavior of some borylenes and diborynes, which form CO complexes analogous to TMs, bind H2 and unsaturated organic substrates under mild conditions and even activate N2 . 2

References: [ 1a] P. P. Power, Nature, 2010, 463, 171; [b] G. C. Welch, R. R. San Juan, J. D. Masuda, D. W. Stephan, Science, 2006, 314, 1124; [c] G. D. Frey, B. Lavallo, B. Donnadieu, W. W. Schoeller, G. Bertrand, Science, 2007, 316, 439. [ 2a] H. Braunschweig, R. D. Dewhurst, F. Hupp, M. Nutz, K. Radacki, C. Tate, A. Vargas, Q. Ye, Nature, 2015, 327; [b] H. Braunschweig, K. Radacki, A. Schneider, Science, 2010, 328, 345; [c] H. Braunschweig, R. D. Dewhurst, K. Hammond, J. Mies, A. Vargas, K. Radacki, Science, 2012, 336, 1420; [d] M.-A. Légaré, G. Bélanger-Chabot, R. D. Dewhurst, E. Welz, I. Krummenacher, B. Engels, H. Braunschweig, Science, 2018, 359, 896

 

Title:Resonance and Time Resolved Inelastic Light Scattering to Stud Nanoscale Physics in Charge Transfer Relevant Systems
Speaker:Prof Dr Michael A Rübhausen
Date:14th June 2019
Time:11.00am – 12.30pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Assistant Professor Soo Han Sen
Abstract:

The topic involves the measurements of the time resolved behavior of nanoscale physics in charge transfer relevant systems all to elucidate the delicate interplay between electronic and structural degrees of freedom. The first part touches on the physics of composite nanostructured composite materials and its investigation by modern X-Ray and laser based techniques. The second part of the presentation concerns the physics of bio-inorganic model complexes that are relevant for catalytic processes in nature and for bio-mimetic processes. The following experimental techniques will be introduced from an experimental point of view : GISAXS (Grazing Incidence Small angle X-Ray scattering), XAFS (XRay Absorption Fine Structure spectroscopy), M-edge RIXS (Resonance Inelastic X-Ray Scattering) at an FEL (Free Electron laser), Resonance and Time Resolved Raman, time resolved Fluorescence Spectroscopy.

 

Title:Re-Inventing Darwinism from the Ground Up
Speaker:Professor Steven A. Benner
Date:17th May 2019
Time:11.00am – 12.30pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Assistant Professor Chen Gang
Abstract:

By dragging scientists across uncharted terrain where they are forced to answer unscripted questions, "Grand Challenge" synthesis can drive discovery and paradigm change in ways that hypothesis-directed research cannot. Here, our grand challenge in synthetic biology seeks to reproduce the Darwinism displayed by terran biology, but on a molecular platform different from standard DNA; access to Darwinism is believed by many to distinguish the living state from the non-living state. This recognizes that alien Darwinism, with a natural history (including origins) independent of terran Darwinism, might support Darwinism on a different biopolymer. Here, we explore the possibility that Darwinism can be universally supported by any biopolymer that has just two structural features, (a) an ability to fit into a Schrödingerian "aperiodic crystal", lattice, and (b) a "polyelectrolyte" backbone.

1. Hoshika, S., Leal, N.A., Kim, M.-J., Kim, M.-S., Karalkar, N.B., Kim, H. J., Bates, A.M., Watkins Jr., N.E., SantaLucia, H.A., Meyer, A.J., DasGupta, S., Piccirilli, J.A., Ellington, A.D., SantaLucia Jr., J., Georgiadis, M.M., Benner, S.A. (2019) Hachimoji DNA and RNA. A Genetic System with Eight Building Blocks. Science 363, 884-887. 2. Hoshika, S., Singh, I., Switzer, C., Molt, R.W., Leal, N.A., Kim, M.-J., Kim, M.-S., Kim, H.-J. Georgiadis, M.M., Benner, S.A. (2018) "Skinny" and "Fat" DNA: Two new double helices. J. Am. Chem. Soc. 140, 11655-11660. 3. Zhang, L., Yang, Z., Sefah, K., Bradley, K.M., Hoshika, S., Kim, M.-J., Kim, H.-J., Zhu, G., Jimenez, E., Cansiz, S., Teng, I.-T., Champanhac, C., McLendon, C., Liu, C., Zhang, W., Gerloff, D. L., Huang, Z., Tan, W.-H., Benner, S. A. (2015) Evolution of functional six-nucleotide DNA. J. Am. Chem. Soc. 137, 6734-6737.

 

Title:Bioanalytics using Plasmonic Nanostructures
Speaker:Professor Wolfgang Fritzsche
Date:16th May 2019 
Time:11.00 am to 12.30 pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Associate Professor Ling Xing Yi
Abstract:

Novel requirements for bioanalytical methods emerge due to trends such as personalized medicine or pathogen monitoring in environment and food. Here, innovative tools for diagnostics are needed, to be used outside of dedicated laboratories and with less qualified personnel, at minimal costs. Plasmonic nanostructures promise to provide sensing capabilities with the potential for ultrasensitive and robust assays in a high parallelization, and without the need for marker. Upon binding of molecules, the localized surface plasmon resonance (LSPR) of these structure is changed, and can be used as sensoric readout [1]. This is possible even on a single nanostructure level, using optical darkfield detection introduced more than 100 years ago [2], as demonstrated for DNA detection [3]. In contrast to SPR, LSPR senses only in a very thin layer (on the scale of the particle diameter), resulting in an efficient background suppression [4]. In order to multiplex this approach, an imaging spectrometer based on a Michelson interferometer has been developed, able to readout a whole array of sensors in one step [5]. On the sensor side, microarrays of gold nanoparticle spots were fabrictaed using spotting of pre-synthesized gold nanoparticles [6]. Such chemically synthesized particles allow for a cost-efficient generation of highly crystalline particles as nanosensors; by using microfluidic approaches, a high quality and reproducibility can be achieved [7]. The functionalization of the various particle spots is realized by spotting thiolized DNA onto each spot separately. Using this approach, a multiplex DNA-based detection of fungal pathogens involved in sepsis was possible [8]. Besides sensing, individual plasmonic nanostructures can be also used to optically manipulate biomolecular structures such as DNA. Attached particles can be used for local destruction [9] or cutting as well as coupling of energy into (and guiding along) the molecular structure upon laser irradiation [10]. The resonance wavelength of these particles can not only manipulated by their inherent properties (material, geometry) or their surrounding, but also by coupling with adjacent metal films due to interferometric effects [11] or gap modes. This effects is also usable for a novel sensing approach by inserting a flow-through channel between particle and the metal film mirror, analyte particle moving through the channel will change the refractive index in the space between particle and mirror and thereby change the LSP resonance observed.

[1] A. Csaki, T. Schneider, J. Wirth, N. Jahr, A. Steinbrück, O. Stranik, F. Garwe, R. Müller and W. Fritzsche, Philosophical Transactions A 369, 3483-3496 (2011). [2] T. Mappes, N. Jahr, A. Csaki, N. Vogler, J. Popp, W. Fritzsche. Angew Chem Int Ed 51, 11208-11212 (2012) [3] T. Schneider, N. Jahr, A. Csaki, O. Stranik and W. Fritzsche, J Nanopart Res 15, 1531 (2013) [4] J. Jatschka, A. Dathe, A. Csaki, W. Fritzsche, O. Stranik. Sensing and BioSensing Research 7, 62-70 (2016) [5] D. Zopf, J. Jatschka, A. Dathe, N. Jahr, W. Fritzsche, O. Stranik. Biosensors and Bioelectronics 81, 287-293 (2016) [6] A. Pittner, S. Wendt, D. Zopf, A. Dathe, N. Grosse, A. Csaki, W. Fritzsche, O. Stranik. Analytical and Bioanalytical Chemistry (2019) accepted [7] Thiele M, Soh J Z E, Knauer A, Malsch D, Stranik O, Müller R, Csáki A, Henkel T, Köhler J M and Fritzsche W 2016 Chemical Engineering Journal 288 432–40 [8] D. Zopf, A. Pittner, A. Dathe, N. Grosse, K. Arstila, J. Toppari, W. Schott, D. Dontsov, G. Uhlrich, W. Fritzsche, O. Stranik. ACS Sensors (2019) in revision [9] A. Csaki, F. Garwe, A. Steinbrück, G. Maubach, G. Festag, A. Weise, I. Riemann, K. König and W. Fritzsche, Nano Letters 7 (2), 247-253 (2007). [10] J. Wirth, F. Garwe, G. Haehnel, A. Csaki, N. Jahr, O. Stranik, W. Paa and W. Fritzsche, Nano Letters 11 (4), 1505-1511 (2011).; J. Toppari, J. Wirth, F. Garwe, O. Stranik, A. Csaki, J. Bergmann, W. Paa, W. Fritzsche, ACS Nano 7, 1291-1298 (2013); J. Wirth, F. Garwe, J. Bergmann, W. Paa, A. Csaki, O. Stranik, W. Fritzsche. Nano Letters 14, 570-577 (2014) [11] J. Wirth, F. Garwe, R. Mayer, A. Csaki, O. Stranik, W. Fritzsche: Nano Letters 14, 3809-3816 (2014)

 

Title:Developing Earth-Abundant Photoredox Catalysts
Speaker:Professor Eli Zysman-Colman
Date:7th May 2019
Time:11.00 am to 12.30 pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Assistant Professor Soo Han Sen
Abstract:

Visible light photoredox catalysis has exploded into the consciousness of the synthetic chemist. The large majority of the conditions used rely on ruthenium or iridium based photocatalysts. Issues pertaining to toxicity of these compounds and sustainability must be addressed in order for photoredox catalysis to become more widely adopted by industry. In this presentation, I will focus on our development of Cu(I) and Co(III) photocatalysts and their use in a number of relevant organic transformations.

 

Title:Why Study and Control the Conformation and Supramolecular Arrangement of Molecules by CD/SRCD Spectroscopy? Applications to Drugs, Proteins, Nucleic Acids, Nanocrystal Cellulose, Light Harvesting Complex II and Optoelectronic Materials.
Speaker:Dr Giuliano Siligardi
Date:15th April 2019
Time:2.30pm to 4.00pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Associate Professor Tan Howe Siang
Abstract:

The function/activity of molecules such as drugs, proteins, nucleic acids (DNA, G-quadruplex, imotifs and RNA) and carbohydrates is strictly related to their conformational properties and behaviours under perturbing conditions like solvent composition, ionic strength, concentration, pH, temperature, pressure, UV irradiation, ligand interactions, and detergents. Supramolecular arrangements are also of paramount importance for chiral polymers and optoelectronic materials. The highly collimated beamlight of Diamond B23 beamline for synchrotron radiation circular dichroism (SRCD) has enabled for the first time a variety of experiments. CD imaging (CDi) of thin films of chiral materials (thin films and thin crystals) at unprecedented spatial resolution (50 micron) in the far-UV to visible region (180-650nm), high throughput CD (HTCD) using 96-cell plates to screen ligand binding interactions and optimise crystallographic solvent conditions will be presented.

 

Title:Nanoparticles from Helium Droplets Synthesis: Towards New Materials for Plasmonics and Catalysis
Speaker:Dr Florian Lackner
Date:9th April 2019
Time:3.00pm to 4.30pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Associate Professor Loh Zhi Heng
Abstract:

Recently we introduced the helium droplet approach as a novel and versatile method for the synthesis of multicomponent nanoparticles, in particular, core@shell nanoparticles, and the formation of nanostructures assembled by the deposition of particles on different substrates. The deposition process is very soft, which allows for a deposition of nanoparticles on ultrathin substrates such as hexagonal boron nitride (h-BN) with a thickness of only a few monolayers [1]. The h-BN substrate is particularly well suited for plasmon spectroscopy of nanoparticles in a scanning transmission electron microscope. For Ag@Au core@shell nanoparticles we show that the helium droplet approach allows to control the spectral position of the localized surface plasmon resonance (LSPR) peak by adjusting the Ag:Au ratio. Bimetallic KAu nanoparticles are particularly interesting for plasmonics. Employing the helium droplet synthesis approach, the highly reactive potassium can be handled and coated with gold. Plasmonic and catalytic properties are combined in Ag@ZnO particles. Besides many other combinations, we also started to investigate CoO nanoparticles deposited on 10 nm thick silicon nitride, a substrate which enables the investigation of nanoparticles by high-order harmonic generation (HHG) based XUV absorption spectroscopy.

[1] A. Schiffmann et al., J. Appl. Phys. 125, 023104 (2019).

 

Title:Nanomaterials Synthesized in Helium Droplets
Speaker:Professor Wolfgang E. Ernst
Date:9th April 2019
Time:11.00am to 12.30pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Associate Professor Loh Zhi Heng
Abstract:

By doping superfluid droplets of 106 to 1010 helium atoms (HeN) with foreign atoms or molecules, cold complexes of atomic or molecular species are formed that can either be investigated by molecular beam spectroscopic methods or deposited on solid substrates for surface analysis [1]. In this way, large Cu, Ag, Au, Ni, Co, Fe, Pd, Cr, or V2O5 aggregates of different morphology have been generated and deposited on solid carbon, h-BN, or SiN substrates. Employing different pick-up cells for doping the droplets, nanowires of 2 to 5 nm diameter and around 100 nm length, as well as core-shell clusters with one metal surrounding a core of a different species are produced. Before deposition, time-of-flight mass spectroscopy and laser excitation measurements serve as diagnostics. After surface deposition, the samples are removed and various measurement techniques are applied to characterize the created particles: scanning electron microscopy at atomic resolution, electron tomography [2], temperature dependent SEM and TEM up to 1000 degree C, energy-dispersive x-ray spectroscopy (EDXS), electron energy loss spectroscopy (EELS) and optical absorption. Results of our investigation of the thermal behavior of deposited nanoparticles [3] and the corresponding phase changes and chemical reactivity on the nanoscale will be reported [4, 5].

[1] P. Thaler et al., J. Chem. Phys. 143, 134201-1-10 (2015), [2] G. Haberfehlner et al., Nature Communications 6, 8779-1-6 (2015). [3] M. Schnedlitz, PhysChem ChemPhys 19, 9402-9408 (2017). [4] M. Lasserus, Nanoscale 10, 2017-2024 (2018). [5] M. Schnedlitz, ACS Chemistry of Materials 30, 1113−1120 (2018).

 

Title:PN3(P)Pincer Complexes: Cooperative Catalysis and Beyond
Speaker:Professor Huang Kuo-Wei
Date:29th March 2019
Time:11.00am to 12.30pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Associate Professor Naohiko Yoshikai
Abstract:

Pincer transition metal complexes have versatile reactivities to catalyze many organic transformations and to activate strong chemical bonds. In particular, complexes with ligand derived from tridentate pyridine-based framework exhibit interesting reactivities. We have developed a novel platform of pincer-type PN3(P)-ligands which are capable of interacting with the substrates during the reaction. Rich reactivities have been observed with their catalytic activities being explored. In very recent work, we have witnessed that the seemingly small change by replacing the CH2 spacer in the pyridine-based pincer complex with an NH group has dramatically influenced the thermodynamic and kinetic properties, and in some cases the catalytic behaviors of the corresponding metal complexes. It is conceivable that this new class of transition metal pincer complexes will offer exciting opportunities for the development of novel catalytic applications in the petrochemical and energy sectors. 

Key References 1. Li, H.; Gonçalves, T. P.; Lupp, D.; Huang, K.-W. ACS Catalysis 2019, 9, 1619-1629. 2. US Patent No. 8,598,351 (2013); Title: Phospho-Amino Pincer-Type Ligands and Catalytic Metal Complexes Thereof. 3. Li, H.; Zheng, B.; Huang, K.-W. Coord. Chem. Rev. 2015, 293-294, 116-138. 4. Gonçalves, T. P.; Huang, K.-W. J. Am. Chem. Soc. 2017, 139, 13442-13449 5. Eppinger, J.; Huang, K.-W. ACS Energy Lett. 2017, 2, 188-195. 6. Zhang, Y.; Chen, X.; Zheng, B.; Guo, X.; Pan, Y.; Chen, H.; Li, H.; Min, S.; Guan, C.; Huang, K.-W.; Zheng, J. Proc. Natl. Acad. Sci. U.S.A. 2018, 115, 12395-12400. 7. Li, H.; Gonçalves, T. P.; Hu, J. Zhao, Q.; Gong, D.; Lai, Z.; Wang, Z.; Zheng, J.; Huang, K.-W. J. Org. Chem. 2018, 83, 14969-14977. 8. Wang, X.; Ang, E. P. L.; Guan, C.; Zhang, W.; Wu, W.; Liu, P.; Zheng, N.; Zhang, D.; Lopatin, S.; Lai, Z.; Huang, K.-W. ChemSusChem 2018, 11, 3591-3598. 9. Chen, T.; Li, H.; Qu, S.; Zheng, B.; Lai, Z.-P.; Wang, Z.-X.; Huang, K.-W. Organometallics 2014, 33, 4152-4155. 10.Qu, S.; Dang, Y.; Song, C.; Wen, M.; Huang, K.-W.; Wang, Z.-X. J. Am. Chem. Soc. 2014, 136, 4974-4991.

 

Title:Catalytic Enantioselective Synthesis of Planar-Chiral Transition-Metal Complexes and Their Application in Organic Transformations
Speaker:Professor OGASAWARA Masamichi
Date:22nd March 2019
Time:3.00pm to 4.30pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Professor Chiba Shunsuke
Abstract:

Planar-chiral transition-metal complexes, which include properly substituted metallocenes/half-metallocenes and (p-arene) chromium complexes, are important chiral scaffolds in organic and organometallic chemistry. In spite of the increasing utilities of these molecules in asymmetric synthesis, their preparative methods in optically active forms are rather limited. Whereas the classical methods typically require stoichiometric chiral reagents or auxiliaries, asymmetric catalysis of preparing such planar-chiral molecules has been virtually unexplored up until very recently. 1 Olefin-metathesis reactions using well-defined catalysts, such as the Grubbs' ruthenium catalysts and the Schrock's molybdenum catalysts, have been powerful tools in organic synthesis and we2 and others have demonstrated their usefulness in the modulation of metal-containing compounds as well. In 2002, we reported preparation of [4]metallocenophanes by the ring-closing metathesis reaction of 1,1'-diallylmetallocenes. 2a The Mo-catalyzed asymmetric ring-closing metathesis (ARCM) was highly effective for enantioselective synthesis of the various planar-chiral ferrocenes giving the RCM products in up to 99% ee. 3 The similar method could be applied to the asymmetric synthesis of (p-arene)chromium(0) complexes4 as well as (h5-cyclopentadienyl)manganese(I) complexes5 with excellent enantioselectivity. Scope and limitation of these methods as well as applications of the planar-chiral productsin asymmetric organic transformationswill be described in detail.

Publications from our group in this projects: 1. Reviews: (a) Synthesis 2009, 1761; (b) TL 2015, 56, 1751. 2. (a) JACS 2002, 124, 9068; (b) OM 2003, 22, 1174; (c) OM 2008, 27, 6565; (d) JOMC 2011, 696, 3987; (e) OM 2013, 32, 6593; (f) ASC 2015, 357, 2255. 3. (a) OM 2006, 25, 5201; (b) PAC 2008, 80, 1109; (c) JACS 2010, 132, 2136; (d) CEJ 2013, 19, 4151; (e) OM 2015, 34, 1197; (f) OL 2015, 17, 2286; (g) ACS Catal. 2016, 6, 1308 4. a) ACIE 2012, 51, 2951; (b) JACS 2014, 136, 9377; (c) CEJ 2015, 21, 4954. 5. (a) JACS 2017, 139, 1545; (b) OM 2017, 36, 1430; (c) OM 2017, 36, 4061.

 

Title:Advances in Target-Oriented Synthesis – A Recent Account
Speaker:Professor David Chen
Date:21st March 2019
Time:2.30pm to 4.00pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Professor Loh Teck Peng
Abstract:

Over the course of history, Target-Oriented Organic Synthesis has served admirably as a vehicle for advancing chemical, physical and biological sciences. Concurrently, the thought-process behind a synthetic chemist’s mind, as reflected in the masterfully designed and executed synthetic campaign, has also evolved tremendously over the last two decades. While serving its multifaceted role in methodological developments, structural and biological investigations, we pondered the underlying scientific essence that is uniquely bestowed by target-oriented Total Synthesis. In this talk, snapshots of current projects from a design viewpoint will be discussed, together with personal thoughts of Target-Oriented Organic Synthesis. Hopefully, this lecture will transform our perception of total synthesis beyond simply a “compound-making” exercise, and uncover new possibilities for future directions.

References: Reviews: 1) Adventures in Total Synthesis – A Personal Account. Synlett. 2011, 17, 2459-2481; 2) A Personal Perspective on Organic Synthesis: Past, Present, and Future. Isr. J. Chem. 2018, 58, 85-93. Research articles: 1) A Local-Desymmetrization-Based Divergent Synthesis of Quinine and Quinidine. Angew. Chem. Int. Ed. 2019, 58, 488-493 2) A Desymmetrization-Based Total Synthesis of Reserpine. Angew. Chem. Int. Ed. 2018, 57, 16152-16156 3) Asymmetric Total Syntheses of Communesin F and a Putative Member of the Communesin Family. Angew. Chem. Int. Ed. 2017, 56, 14237-14240 4) An Asymmetric Pathway to Dendrobine by a Transition-Metal-Catalyzed Cascade Process. Angew. Chem. Int. Ed. 2017, 56, 12250-12254 5) Total Synthesis of Actinophyllic Acid. Angew. Chem. Int. Ed. 2017, 56, 12277-12281 6) Total Synthesis of Strychnine. Chem. Eur. J. 2017, 23, 16189-16193.

 

Title:Design Strategy toward Recyclable and Highly Efficient Heterogeneous Catalysts for the Hydrogenation of CO2 to Formate
Speaker:Professor Sungho Yoon
Date:12th February 2019
Time:11.00am to 12.30pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Assistant Professor Soo Han Sen
Abstract:

One bottleneck in the realization of CO2 conversion into value-added compounds is the lack of catalysts with both excellent activity and recyclability. Herein, a catalyst is designed for the hydrogenation of CO2 to formate to boost up these features by considering the leaching pathway of previously reported heterogenized catalyst; the design strategy incorporates oxyanionic ligand(s) in the coordination sphere to provide a pathway for both preventing the deleterious interactions and assisting the heterolysis of H2 . The tailored heterogenized catalyst, [bpy-CTF-Ru(acac)2 ]Cl, demonstrated excellent recyclability over consecutive runs with a highest turnover frequency of 22 700 h–1, and produced a highest formate concentration of 1.8 M in 3 h. This work is significant in elucidating new principles for the development of industrially viable hydrogenation catalysts.

 

Title:Atomic-Resolution Electron Microscopy for Seeing Molecular Motion, Assembly and Reactions
Speaker:Associate Professor Koji Harano
Date:11th February 2019
Time:11.00am to 12.30pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Assistant Professor ITO Shingo
Abstract:

Whereas a spatial- and time-average of molecular ensembles has been the conventional source of information on molecular structures, atomic resolution movies of single organic molecules and molecular clusters obtained by singlemolecule atomic-resolution real-time electron microscopy (SMART-EM) developed by us have recently emerged as a new tool to study the time evolution of the structures of individual molecules.1 The key of our technique is that we observed little sign of decomposition of the specimen molecules encapsulated in or attached to a single-walled carbon nanotube (CNT) as opposed to solid organic materials. The high specimen stability and the real-time movie recording enable us to study on the conformation of each C−C bond in single perfluoroalkyl fullerene molecules, 2 dynamic conformational changes of linear molecules,3,4 and structure of organic nanoclusters formed as a precursor of a crystal nucleus from supersaturated solution.5 We are also able to study chemical reactions from a movie of individual reaction events occurring at various temperature by using CNT as a sensitizer and a thermal bath. Statistical analysis of electron-beam driven conversion of a van der Waals C60 dimer to a [2+2] dimer over many molecules and temperatures provides an experimental proof of correlation between conventional transition state theory and statistics of individual molecular events.6

1 Nakamura, E. Acc. Chem. Res. 2017, 50, 1281–1292. 2 Nakamura, E. et al. J. Am. Chem. Soc. 2008, 130, 7808–7809. 3 Harano, K. et al. J. Am. Chem. Soc. 2014, 136, 466–473. 4 Gorgoll, R. M. et al. J. Am. Chem. Soc. 2015, 137, 3474–3477. 5 Harano, K. et al. Nat. Mater. 2012, 11, 877–881. 6 Okada, S. et al. J. Am. Chem. Soc. 2017, 139, 18281–18287.

 

Title:Making Two Triplets from One Singlet Exciton – Singlet Fission Yield of TIPS – Pentacene in a Polymer Matrix
Speaker:Associate Professor Tak W. Kee
Date:8th February 2019
Time:2.00pm to 3.30pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Associate Professor Tan Howe Siang
Abstract:

Singlet fission is a process by which a singlet exciton is dissociated to form two triplet excitons through a spin allowed process within a pair of molecules.1 Singlet fission is attracting significant interest in renewable energy research because it addresses a critical issue in single-junction solar cells, of which the efficiency is limited to ~33%.2 Singlet fission solar cells can potentially minimize thermalization of the initially prepared exciton, leading to a theoretical efficiency limit of 45%.3-4 The accepted mechanism of singlet fission involves converting a singlet exciton to a correlated triplet pair (1TT), which further dissociates to form two separated triplet excitons.1 Owing to the requirement of proximity of the two molecules for singlet fission, the intermolecular distance is expected to play a significant role in the quantum yield of triplet excitons. We have developed an aqueous nanoparticle system in which TIPS-pentacene, a compound that is known to undergo efficient singlet fission, in an inert, amorphous host polymer matrix. We have employed a combination of femtosecond transient absorption and time-resolved fluorescence spectroscopy to study the TIPS-pentacene/host polymer nanoparticles. The relaxation dynamics of excited state TIPS-pentacene exhibit a strong dependence on intermolecular distance, indicating a control of processes including singlet migration and singlet fission. Kinetic modelling of the time-resolved spectroscopic results indicates that only half the 1TT population undergoes dissociation to form triplet excitons whereas the other half relaxes to the ground state. Our most recent work involves a combination of molecular dynamics simulation and Monte Carlo simulation to model the time-resolved fluorescence and polarization anisotropy experimental results. This work reveals the roles of singlet fission, singlet migration and aggregation of TIPS-pentacene in the host polymer matrix, contributing to further understanding of singlet fission mechanism.

References 1. M. Smith, and J. Michl, Chem. Rev. 2010, 110, 6891. 2. W. Shockley and H. J. Queisser, J. Appl. Phys. 1961, 32, 510. 3. M. J. Y. Tayebjee, A. A. Gray-Weale and T. W. Schmidt, J. Phys. Chem. Lett. 2012, 3, 2749. 4. M. C. Hanna and A. J. Nozik, J. Appl. Phys. 2006, 100, 074510

 

Title:Alkali Metal Mediation in Synergistic Synthesis and Homogeneous Catalysis
Speaker:Professor R. E. Mulvey
Date:18th January 2019
Time:11.00 am to 12.30 pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Assistant Professor Felipe Garcia
Abstract:

Alkali metals have played a seminal role in the development of synthetic chemistry for nearly a century most often in the form of lithium alkyl or lithium amide reagents. If these are classified as first generation metallating agents, we are currently in the midst of an emerging second generation where partnering the alkali metal with a second metal such as magnesium or zinc can create bimetallic cooperativities that lead to reactivities and selectivities outside the scope of the unimetallic systems. Showcasing some of our recent advances in this area, this presentation will demonstrate examples where the two metal partners work together to effect novel metallations of aromatic substrates. The extension of this bimetallic cooperativity theme from stoichiometric systems to the catalytic regime will also be included, focusing on examples in hydroelementation catalysis.

1. V. A. Pollard, S. A. Orr, R. McLellan, A. R. Kennedy, E. Hevia and R. E. Mulvey, Chemical Communications, 2018, 54, 1233. 2. V. A. Pollard, M. Ángeles Fuentes, A. R. Kennedy, R. McLellan and R. E. Mulvey, Angewandte Chemie-International Edition, 2018, 57, 10651. 3. L. E. Lemmerz, R. McLellan, N. R. Judge, A. R. Kennedy, S. A. Orr, M. Uzelac, E. Hevia, S. D. Robertson, J. Okuda and R. E. Mulvey, Chemistry-a European Journal, 2018, 24, 9940. 4. R. McLellan, M. Uzelac, A. R. Kennedy, E. Hevia and R. E. Mulvey, Angewandte Chemie-International Edition, 2017, 56, 9566. 5. R. McLellan, A. R. Kennedy, S. A. Orr, S. D. Robertson and R. E. Mulvey, Angewandte Chemie-International Edition, 2017, 56, 1036.

 

Title:Oxidation-Induced C-H Functionalization and Catalytic Oxidative Cross-Coupling
Speaker:Professor Aiwen Lei
Date:9th January 2019
Time:11.00 am to 12.30 pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Professor Shunsuke Chiba

 

Title:Cascades of Interrupted Pummerer Reaction and Sigmatropic Rearrangement
Speaker:Professor Hideki Yorimitsu
Date:4th January 2019
Time:11.00 am to 12.30 pm
Venue:SPMS Research & Graduate Studies Conference Room
Host:Professor Shunsuke Chiba
Abstract:

A new class of Pummerer chemistry has emerged as a powerful tool in organic synthesis. The new technology consists of a beautiful cascade of an interrupted Pummerer reaction and the subsequent [3,3] sigmatropic rearrangement. The following two topics, along with some very recent results, will be discussed to showcase the high synthetic potential of classical yet revitalizing organosulfur chemistry.1) The reactions are unique and game-changing because they are efficient, robust, redox-neutral, regioselective, and metal-free, which perfectly fits the need of modern organic synthesis.

(1) Practical and modular synthesis of benzofurans from phenols and alkenyl sulfoxides2

(2) Metal-free approach to biaryls from aryl sulfoxides and phenols by temporarily sulfur-tethered regioselective C–H/C–H coupling3)

1) H. Yorimitsu, Chem. Rec. 2017, 17, 1156. 2) K. Murakami, H. Yorimitsu, A. Osuka, Angew. Chem. Int. Ed. 2014, 53, 7510. T. Yanagi, S. Otsuka, Y. Kasuga, K. Fujimoto, K. Murakami, K. Nogi, H. Yorimitsu, A. Osuka, J. Am. Chem. Soc. 2016, 138, 14582.