Synthetic Chemistry & Catalysis
Synthetic chemistry aims at development of new chemical reactions and their application to preparation of target molecules of unique properties such as biologically active natural products, drugs, polymers, functional materials, etc. Synthetic chemistry is strongly tied with physics and biology through design, production, supply, and functionalization of valuable molecules, thus greatly contributing to our human society.
Synthetic chemistry at NTU is a vital component of NTU’s commitment to research and teaching in the life sciences, being at the forefront of development of new methodology and catalysis in chemical synthesis of complex molecules and functional materials in highly selective fashion (i.e. asymmetric synthesis). The exceptional scientific creativity as well as productivity and training excellence of manpower have been demonstrated by numerous publications in high-impact factor journals, large-scale grant support (NRF fellowship, NAP, Tier 2, ASTAR-PSF, etc), numerous international recognition/awards, and highly successful graduate students who have achieved leadership positions in academia, chemical/pharmaceutical industry, and local research agencies. Among NTU’s excellences in synthetic chemistry, especially of worthy to note as existing world-class strengths and achievements are development of robust catalysis/catalytic systems enabling conceptually novel and highly efficient molecular transformations. Synthetic chemistry needs further development for creation of cutting-edge functional molecules by exploiting highly efficient molecular transformations (methodology development) in consideration of the following keywords, "synthetic power", "environmental harmony", "atom economy", and "sequential transformations". Current synthetic organic chemistry has been developed mainly based on stepwise syntheses in batch. This should be further improved by introducing novel technologies to integrate multiple step reactions in one-pot or in one-flow. The followings are representative initiatives on synthetic chemsitry for methodology and technology development:
- Catalytic aliphatic C-H bonds functionalization
- Environmentally benign molecular transformations performing without noble toxic transition-metals (i.e. with ubiquitous front-row transition-metal catalysts such as Cu, Fe, Ni, Mn etc; with highly performing organo-catalysts)
- Synthesis of complex natural products and functional materials
- Biomass conversion
- Novel strategies for biomolecules functionalization in vitro and in vivo
- Catalysis in vivo chemical transformation for new frontiers in chemistry and biology
Development of new technologies for integrated synthesis toward continuous manufacturing:
Outputs from these initiatives also contribute for industrial continuous manufacturing (e.g. manufacturing APIs in pharmaceutical industries, that are key focus for the current local
Teck Peng LOH, Roderick BATES, Robin Yonggui CHI, Shunsuke CHIBA, Jason ENGLAND, Pak Hing LEUNG, Xuewei LIU, Sreekumar PANKAJAKSHAN, Sumod A. PULLARKAT, Han Sen SOO, Mihaiela STUPARU, Choon Hong TAN, Motoki YAMANE, Naohiko YOSHIKAI, Steve ZHOU, Bengang XING, Yanli ZHAO
The medicinal chemistry programs in CBC place special emphasis on chemical synthesis and on the utilization of this expertise in addressing problems of medicinal and biomedical significance. The Division is composed of faculty members with diversified research interests representing synthetic, analytical, natural products, and biological chemistry as well as computational chemistry. Current faculty research areas include: 1) design and synthesis of novel anticancer and antiviral agents; 2) computational modeling and simulation of biomolecular structure, dynamics and interaction; synthesis and biological study of cell surface-bound carbohydrates such as sialylpolysaccharides and lipopolysaccharides; phage display and peptide chemistry; 4) synthesis of biologically interesting natural products; etc.
Roderick BATES, Robin CHI, Shunsuke CHIBA, Teck Peng LOH, Xuewei LIU, Choon Hong TAN, Bengang XING, Dawei ZHANG, Gang CHEN.
Imaging, Sensing and Detection
Imaging cells and their components is critical for understanding protein functions, biological pathways and the efficacy of therapeutics. Fluorescent/bioluminescent organic dyes are the mainstream labels but they have shortcomings. Designing robust alternatives is thus of significance for the next generation of labels. In a broader context, sensing and detection of specific chemicals has a great impact on society. Pollutants, toxic chemicals, pathogenic agents, trace amount of explosives, for example, need constant monitoring in a variety of different situations. The key to detecting these chemicals is to convert the chemical signals to electric or photonic signals that can be accurately measured by instruments.
Chemists are best at designing new processes, which is typically driven by improved fundamental understandings. We are interested in physical and chemical processes underlying problems such as solubility, fluorescence quenching, photobleaching, protein-label interactions, label-cell interactions, etc. The improvement and extension of the scope of existing methods are important, but the development of new methodologies and strategies can lead to quantum leaps in a field. Our objectives are (1) developing efficient and multiplexing labels; (2) understanding the properties of dyes and plasmonic nanostructures; (3) studying the recognition among biomolecules; (4) electrochemical sensing; (5) membrane-based biosensors; (6) computational simulation of recognition interactions; and (7) developing new imaging and detection schemes.
Alessandra BONANNI, Hongyu CHEN, Gang CHEN, Weng Kee LEONG, Xing Yi LING, Zhi Heng LOH, Martin PUMERA, Fangwei SHAO, Howe Siang TAN, Edwin Kok Lee YEOW, Dawei ZHANG, Cheuk Wai SO, Bengang XING, Yanli ZHAO, Richard WEBSTER
Main Group Chemistry
More than in any other section of the periodic table, the main group elements (i.e., s and p-block) are very dissimilar. This diversity provides them with a much wider range of properties than any other block of elements in the periodic table. These properties range from highly reactive non-metallic elements (such as fluorine), through semi-metals (e.g., silicon) to the highly reactive alkali metals (such as potassium). The always surprising and sometime unpredictable nature of main group chemistry provides an exciting research environment for fundamental and applied chemistry involving these elements. CBC has a strong team in Main Group research. The focused research enables scholars to better exchange ideas and explore emerging research areas and to work more effectively with industry, any other research organizations and the community.
Main Group research in CBC group is focused on expanding knowledge concerning the synthesis of compounds containing main group elements and the investigation of their reactivity patterns with an emphasis on their possible applications. A wide range of research areas are represented within ‘Main Group Chemistry @ NTU’. From ‘Blue skies’ projects involving: (a) Novel Bonding and Structural Paradigms of main group compounds, (b) Main group organometallic Chemistry its applications, (c) Main elements in catalysis and its applications and (d) Influence of Main group elements in wider contexts (such as, heterocyclic chemistry, carbon analogues, low-valent compounds, transition metal clusters and Asymmetric synthesis) to their applications in a wide range of contexts: (a) Electronics (e.g., Molecular materials for optoelectronics, New π-electron Systems for electronic devices, Main group-transition metal systems for molecular wires and Main Group magnetic systems); (b) enhanced materials (such as photocatalyst doping or grapheme doping); and (c) energy storage ( Precursors to battery materials and hydrogen storage).
Felipe GARCIA, Rei KINJO, Weng Kee LEONG, Sumod A. PULLARKAT, Cheuk-Wai SO, Dragoslav VIDOVIC, Francois MATHEY, and Steve ZHOU.
Chemistry at the space-time limit
A variety of state-of-the-art spectroscopic techniques are employed to study the elementary processes that occur in chemical and biological systems on ultrasmall length scales (single-molecule spectroscopy) and ultrashort timescales (ultrafast phenomena). In the single-molecule spectroscopy domain, ultra-sensitive techniques are developed to better understand fundamental photophysical reactions that govern the efficiency of light-driven devices including solar cells. Single-molecule (spectro)microscopy is also utilized to elucidate drug-substrate (e.g., bacteria and cancer cells) interaction in order to design optimal antibacterial and cancer treatments. In the area of ultrafast phenomena, one main area of research is in the development and applications of ultrafast multidimensional spectroscopy. This spectroscopy measures new observables that are otherwise hidden in conventional transient absorption/pump probe spectroscopies, particularly in complex systems. One application is in studying the complex multistep ultrafast energy transfer processes in photosynthetic light harvesting complexes. Another research theme is the investigation of coherent electronic and vibrational dynamics that are induced by the strong-field-ionization or ultrabroadband photoexcitation of molecules or nanomaterials. These studies employ optical pump-probe spectroscopy with few-cycle optical pulses, as well as soft X-ray photoabsorption and photoelectron spectroscopies with femtosecond to attosecond time resolution. In a new direction, a photoemission electron microscope is combined with a femtosecond vacuum ultraviolet light source to investigate the ultrafast dynamics of materials with ~40-nm space-resolution. These studies aim to elucidate the effects of local morphology/defects on the ultrafast carrier dynamics of emergent photovoltaics and optoelectronic materials.
Soo Ying LEE, Zhi Heng LOH, Howe-Siang TAN, and Edwin YEOW.