Article
Chemistry, Organic
Takuya Takashima, Hamdiye Ece, Taiga Yurino, Takeshi Ohkuma
Summary: A new methodology for the synthesis of α-amino nitriles through oxidative cyanomethylation of amines was developed. Nitromethane was used as the methylene source, and Me3SiCN was present without the requirement of an external oxidant. The reaction was catalyzed by AgCN and promoted by a stoichiometric amount of LiBF4. Various amines, including both aromatic and aliphatic compounds, which are usually sensitive to oxidative conditions, could be used in the reaction.
Article
Chemistry, Multidisciplinary
Saikat Das, Azusa Kondoh, Masahiro Terada
Summary: The direct use of cyanohydrin ether derivatives as less acidic pronucleophiles was achieved for the first time in the catalytic enantioselective Michael addition reaction under transition metal free conditions. Chiral bis(guanidino)iminophosphoranes as the higher order organosuperbase facilitated the intended catalytic Michael addition to enones, giving rise to the corresponding products in high yields with moderate to high diastereo- and enantioselectivities in most cases. Further elaboration of the corresponding enantioenriched product was conducted by derivatization into a lactam derivative through hydrolysis followed by cyclo-condensation.
Article
Chemistry, Multidisciplinary
Zhi-Kai Zhang, Ya-Li Feng, Zheng Ruan, Yuan-Qing Xu, Zhong-Yan Cao, Meng-Hua Li, Chao Wang
Summary: This article presents a practical method for 1,2-diborylation of non-activated monosubstituted alkenes via nickel catalysis. The method shows high tolerance towards functional groups and can be applied for the synthesis of drugs and modification of natural product derivatives. Preliminary mechanistic studies suggest the involvement of a Ni(ii) catalytic cycle.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Ying Ding, Jinguo Long, Xianjie Fang
Summary: A nickel-catalyzed hydrocyanation of aliphatic allenes with excellent regioselectivity has been developed. This protocol features mild reaction conditions and good functional group tolerance, providing an efficient catalytic pathway to access various allylic nitriles containing quaternary carbon centers in a one-step fashion. Additionally, preliminary attempts were made to investigate an asymmetric version of this reaction.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Yuan-Zheng Wang, Le'an Hu, Shao-Tao Bai, Xumu Zhang
Summary: A user-friendly and simple catalytic method for the synthesis of high value primary &α;-(trifluoromethyl)aryl-methylamines via ruthenium-catalyzed asymmetric reductive amination of aryl-trifluoromethylketones using cheap NH4OAc as the nitrogen source and H-2 as the reductant is reported. This method tolerates various aromatic functions with electron-withdrawing or -donating substituents, as well as challenging heteroaromatic functions, leading to the formation of primary &α;-(trifluoromethyl)aryl-methylamines with excellent chemoselectivities, enantioselectivities, and useful yields (80-97% ee, 51-92% isolated yields).
Review
Chemistry, Multidisciplinary
Zuxiao Zhang, Pinhong Chen, Guosheng Liu
Summary: Radical-involved transition metal catalysis enables new reactivities, and copper-catalyzed radical relay shows great potential in C(sp(3))-H functionalization. Significant progress has been made in asymmetric C-H functionalization through ligand design.
CHEMICAL SOCIETY REVIEWS
(2022)
Review
Chemistry, Inorganic & Nuclear
Helene Pellissier
Summary: This review presents the recent advancements in the field of enantioselective titanium-catalyzed transformations since the beginning of 2015, demonstrating the effectiveness of chiral green titanium catalysts in promoting various types of reactions. A previous review in a book published in 2016 covered the literature up to the end of 2014. Over the past seven years, a range of highly efficient reactions have been developed.
COORDINATION CHEMISTRY REVIEWS
(2022)
Article
Chemistry, Organic
Weiru Fu, Lina Zhu, Shangzhi Tan, Zhengjia Zhao, Xiangzhu Yu, Lianyue Wang
Summary: The Cu/ABNO-catalyzed aerobic oxidative coupling of diols and primary amines to access N-substituted pyrroles is demonstrated. The reaction proceeds at room temperature using commercially available materials and an O2 balloon as the oxidant. The catalyst system shows a broad substrate scope and good tolerance towards sensitive functional groups, as confirmed by gram-scale experiments.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Song Feng, Baoqi Ren, Lige Li, Fengmin Xia, Zhiyong Tang, Yu Zhang, Xiaoning Liu, Qixuan Lu, Wenge Zhong
Summary: This method achieves the N-heteroaryl-directed Ru-catalyzed asymmetric hydrogenation of α,α-disubstituted vinyl ethers with good to excellent enantioselectivities, providing an attractive approach for synthesizing pharmaceutically active heteroaryl compounds containing chiral ether units.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Multidisciplinary
Liang Fu, Xin Chen, Wenzheng Fan, Pinhong Chen, Guosheng Liu
Summary: A novel asymmetric radical strategy for the straightforward synthesis of atropisomerically chiral vinyl arenes has been developed, proceeding through copper-catalyzed atroposelective cyanation/azidation of aryl-substituted vinyl radicals. The key to the success of the radical relay process is the atroposelective capture of highly reactive vinyl radicals with chiral L*Cu(II) cyanide or azide species. Furthermore, these axially chiral vinylarene products can be easily transformed into atropisomerically enriched amides and amines, enantiomerically enriched benzyl nitriles via an axis-to-center chirality transfer process, and an atropisomerically pure organocatalyst for the chemo-, diastereo-, and enantioselective (4 + 2) cyclization reaction.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Duoyue Tang, Zewen Shen, Sebastian Lechler, Guilong Lu, Ling Yao, Yezi Hu, Xiubing Huang, Martin Muhler, Guixia Zhao, Baoxiang Peng
Summary: In this study, an environmentally friendly catalytic approach using oxygen vacancies-enriched titanium-based oxides and water as solvent at room temperature for the lactonization of various aromatic and aliphatic diols was reported. The results showed that oxygen vacancies as strong Lewis acid sites played a pivotal role in the superior catalytic activities at room temperature, attributed to the enhanced reaction rate of the lactonization process.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Organic
Mengna Liu, Benqiang Cui, Chuntao Zhong, Yanhui Shi, Yanfeng Dang, Changsheng Cao
Summary: A palladium-catalyzed cyanation of aryl dimethylsulfonium salts using K-4[Fe-(CN)(6)]center dot 3H(2)O as the cyanating reagent was successfully developed. The reaction proceeded under base-free conditions and yielded aryl nitriles with up to 92% yields. The protocol also allowed direct transformation of aryl sulfides to aryl nitriles, and the reaction mechanism was investigated using density functional theory calculations.
Article
Chemistry, Organic
Shao-Jie Cheng, Gang Wang, Kui Liu, Zhi-Shi Ye
Summary: A palladium-catalyzed regioselective alpha-amino C-H functionalization has been established via the isomerization of alpha,beta-unsaturated carbonyls including esters, ketones, and amides, providing a straightforward access to a wide range of multicyclic compounds with good yields. This transformation exhibits high regioselectivity, excellent functional group tolerance, and scalability.
Article
Chemistry, Organic
Shao-Jie Cheng, Gang Wang, Kui Liu, Zhi-Shi Ye
Summary: A palladium-catalyzed regioselective alpha-amino C-H functionalization via the isomerization of alpha,beta-unsaturated carbonyls has been established, providing access to a wide array of tricyclic compounds in good yields. This transformation shows high regioselectivity, excellent functional group tolerance, and scalability, and has been used as a key step in the total synthesis of natural products. Preliminary mechanistic studies suggest that the palladium catalyst not only promotes the isomerization of unsaturated carbonyls but also plays a role in the final protonation/cyclization.
Article
Chemistry, Physical
Kaidi Wu, Wentao Zhang, Zichen Zheng, Marc Debliquy, Chao Zhang
Summary: In this study, controllable-sized TiO2 quantum dots were prepared via a rapid microwave-assisted solvothermal method for detecting ppb-level H2S at room temperature. The best sensing performance was achieved by the sample with ultra-small nanostructure and modified surface state, exhibiting high response, rapid response/recovery, low detection limit, good selectivity, and operating stability. The gas sensing mechanism was explained by the synergistic effect of ultra-small size, large specific surface area, and surface defects, and the practical application in detecting fish volatiles was also confirmed.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Qinghua Lyu, Nathanael Hsueh, Christina L. L. Chai
Review
Materials Science, Biomaterials
Qnghua Lyu, Nathanael Hsueh, Christina L. L. Chai
ACS BIOMATERIALS SCIENCE & ENGINEERING
(2019)
Article
Nanoscience & Nanotechnology
Mohammadreza Kosari, Abdul Majeed Seayad, Shibo Xi, Sergey M. Kozlov, Armando Borgna, Hua Chun Zeng
ACS APPLIED MATERIALS & INTERFACES
(2020)
Article
Chemistry, Organic
Aymeric Cervi, Yen Vo, Christina L. L. Chai, Martin G. Banwell, Ping Lan, Anthony C. Willis
Summary: Efficient methods for the synthesis of phenol-derived propiolates and their Au(I)-catalyzed cyclization to give coumarins have been reported. These methods have been successfully applied to the synthesis of natural products such as ayapin and scoparone.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Polymer Science
Ping Sen Choong, Ning Xi Chong, Eric Kwok Wai Tam, Abdul Majeed Seayad, Jayasree Seayad, Satyasankar Jana
Summary: This article presents the development of bio-/CO2-derived nonisocyanate polyurethane (NIPU) coatings, which have high levels of renewable carbon and self-healing properties through three different healing mechanisms: thermo-healing, moisture-healing, and self-healing at room temperature. The coatings feature a unique combination of recyclability and intrinsic healing capabilities, making them ideal for sustainable and functional applications.
Article
Chemistry, Multidisciplinary
Mohammadreza Kosari, Uzma Anjum, Shibo Xi, Alvin M. H. Lim, Abdul Majeed Seayad, Emmanuel A. J. Raj, Sergey M. Kozlov, Armando Borgna, Hua Chun Zeng
Summary: This study explores the impact of a novel maze-like nanoreactor framework (MVmSiO(2)) on CO2 hydrogenation, demonstrating enhanced CO2 activity, improved methanol yield, and prolonged stability. Beyond morphology optimization, the architectural design of the support also plays a significant role in improving reaction performance.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Nathanael Hsueh, Christina L. L. Chai
Summary: This study focused on the design and synthesis of catechol-derived ATRP initiators containing the 2-bromoisobutyryl moiety, and investigated the impact of structural changes on initiator immobilization and subsequent ATRP performance. The results showed that changes in the length of the linker unit bearing the 2-bromoisobutyryl moiety, the introduction of a free amine group, or the replacement of the amide with an ester had profound effects on the ability of the molecule to deposit ATRP-initiator-modified PDA coatings, as well as the subsequent SI-ATRP performance.
Review
Chemistry, Medicinal
Malcolm Z. Y. Choo, Christina L. L. Chai
Summary: Many concepts and guidelines in medicinal chemistry can aid in successful drug discovery and development, but rigid and blind use of them may hinder productivity. Therefore, attention should be given to limitations in assays to increase the chances of successful drug discovery.
Article
Chemistry, Medicinal
Quy Thi Ngoc Tran, Regina Ching Hua Lee, Hon Jin Liu, Danli Ran, Vincent Zhan Lin Low, Dong Quang To, Justin Jang Hann Chu, Christina Li Lin Chai
Summary: This study reports a new class of small-molecule CHIKV inhibitors, oxindole-labdanes, which can effectively block the replication of CHIKV with good selectivity. Compound (E)-42 shows high antiviral activity and minimal cytotoxicity to host cells, demonstrating both prophylactic and therapeutic effects. This finding opens up a new avenue for the development of antiviral drugs against CHIKV infection.
EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY
(2022)
Article
Pharmacology & Pharmacy
Wupeng Liao, Hazel Yu Ci Foo, Thi Ngoc Quy Tran, Christina Li Lin Chai, Wai Shiu Fred Wong
Summary: This study evaluated the protective effects of CalD in a house dust mite (HDM)-induced asthma mouse model. CalD reduced various inflammatory markers and improved lung function in the mice. It modulated the function of alveolar macrophages and had potential as a novel anti-inflammatory compound for allergic asthma.
BRITISH JOURNAL OF PHARMACOLOGY
(2023)
Review
Chemistry, Physical
Mohammadreza Kosari, Alvin M. H. Lim, Yu Shao, Bowen Li, Kelvin M. M. Kwok, Abdul Majeed Seayad, Armando Borgna, Hua Chun Zeng
Summary: Solid siliceous materials play an important role in carbon capture and utilization (CCU) by converting CO2 into valuable chemical commodities. Siliceous catalysts are widely used for CO2 thermal conversion due to their tunable porosity, high thermal resistivity, and ease of preparation. In terms of catalytic performance, siliceous-based catalysts are comparable to non-precious and precious metal catalysts. This review focuses on recent advances in CO2 conversion using silica/silicate-based catalysts, including gas-phase reduction pathways, design and synthesis techniques, and different types of catalysts. The potential for CO2 conversion to hydrocarbons, alcohols, and specialty organic substances using siliceous-based catalysts is emphasized.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Materials Science, Multidisciplinary
Ping Sen Choong, Kwok Wai Eric Tam, Ning Xi Chong, Abdul Majeed Seayad, Jayasree Seayad, Satyasankar Jana
Summary: This study reports a single-step synthesis method for water-soluble and bio-derived linear amine-based non-isocyanatepolyurethanes (NIPUs). These polymers exhibit good water solubility and dispersion, making them potential candidates as anti-soil/dirt redepositioning agents in home care applications. They are also noncytotoxic and non-skin irritants, demonstrating their suitability for further use. The development and utilization of such green, sustainable, and biodegradable NIPUs may replace the current toxic and nondegradable ingredients in various applications.
ACS APPLIED POLYMER MATERIALS
(2023)
Review
Biochemistry & Molecular Biology
Quy T. N. Tran, W. S. Daniel Tan, W. S. Fred Wong, Christina L. L. Chai
Summary: Andrographolide, a widely studied plant secondary metabolite, has diverse pharmacological targets associated with prevalent diseases. Despite documented efficacy in disease models, challenges such as multi-targeting properties and discrepancies in bioavailability have hindered its development as a therapeutic agent.
NATURAL PRODUCT REPORTS
(2021)
Article
Polymer Science
Qinghua Lyu, Nathanael Hsueh, Christina L. L. Chai
Article
Chemistry, Multidisciplinary
Jean-Baptiste Vendeville, Rebecca F. Matters, Anqi Chen, Mark E. Light, Graham J. Tizzard, Christina L. L. Chai, David C. Harrowven
CHEMICAL COMMUNICATIONS
(2019)
