Article
Chemistry, Organic
Marina Briand, Linh D. Thai, Flavien Bourdreux, Nicolas Vanthuyne, Xavier Moreau, Emmanuel Magnier, Elsa Anselmi, Guillaume Dagousset
Summary: Site-selective trifluoromethylation of silyl dienol ethers derived from alpha,ss-unsaturated aldehydes, ketones, and amides was achieved for the first time in the remote gamma position. An unprecedented enantioselective C(sp(3))-H perfluoroalkylation process is disclosed.
Article
Chemistry, Organic
Natalie C. Dwulet, Vincenzo Ramella, Christopher D. Vanderwal
Summary: Soft enolization conditions are shown to be more efficient than hard enolization protocols in regioselectively forming enoxysilanes from unsymmetrical 3-substituted cycloalkanones. The regioselectivities achieved are complementary to those obtained from cycloalkenone conjugate addition/enolate silylation with high selectivity.
Article
Chemistry, Multidisciplinary
Wenke Dong, Zhiyang Ye, Wanxiang Zhao
Summary: Catalytic asymmetric hydroboration of ketone-derived silyl enol ethers using cobalt catalyst has been reported, providing a convenient approach to access valuable enantiopure beta-hydroxy boronic esters. This method features mild reaction conditions, a broad substrate scope, and excellent enantioselectivities, making it potential to streamline the synthesis of complex molecules.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Hao Jia, Andreas P. Haering, Florian Berger, Li Zhang, Tobias Ritter
Summary: In this study, we report the synthesis and application of a novel trifluoromethylating reagent TT-CF3+OTf-, which can be used in various trifluoromethylation reactions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Jian-Yu Zou, Yu-Zhao Wang, Wen-Hui Sun, Wu-Jie Lin, Xue-Yuan Liu
Summary: A mild and facile approach has been developed to construct various perfluoroketones via photo-catalyzed difluoroalkylation of difluoroenoxysilanes. The reaction involves a strategy of combining two fluorine-containing functional groups, allowing for high efficiency, mild conditions, and broad scope. Various fluoroalkyl halides can be utilized as radical precursors, suggesting a potential single-electron transfer pathway in the reaction.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Dongxin Zhang, Lvjia Chen, Huiqing Deng, Ying Zhang, Qihang Cheng, Qian-Feng Zhang
Summary: Asymmetric ring-opening reactions of donor-acceptor cyclopropanes with 1,3-cyclodiones have been achieved for the synthesis of enantioenriched gamma-hydroxybutyric acid derivatives in the presence of Cu(ii)/trisoxazoline catalyst. These reactions provided the desired products in yields of 70% to 93% with enantiomeric excesses of 79% to 99%.
Article
Chemistry, Organic
Xue Chen, Zhen Wang, Jinyong Zhou, Yunkui Liu, Hongwei Jin, Bingwei Zhou
Summary: In this nickel-catalyzed remote hydrosilylation, a range of Z-silyl enol ethers are obtained as major isomers due to nickel-triggered alkene isomerization. Specifically, some alkyl silyl enol ethers that are not easily accessed by traditional methods can be prepared. This reaction features 100% atom economy, simple reaction conditions, and good yields.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Organic
Shahnawaz Khan, Monish Arbaz Ansari, Maya Shankar Singh
Summary: This study presents a chemo- and regioselective cascade annulation between fi-ketothioamides and diazo-substituted hypervalent iodine reagents under transition-metal-free and base-free conditions at room temperature. A divergent construction of fused-heterocyclic scaffold thiazolothiadiazoles has been achieved with the advantages of operational simplicity, scalability, broad substrate compatibility, and mild reaction conditions. This one-pot strategy not only avoids potential toxicity but also broadens the arsenal of synthetic methods to obtain fused N,S-heterocyclic frameworks.
Article
Chemistry, Physical
Hanna Stachowiak-Dluzynska, Grzegorz Hreczycho
Summary: A cobalt-catalyzed addition of hydrosilanes to unsaturated carbon-oxygen bonds has been developed using easily accessible and inexpensive PNP-type pincer ligands. The reaction efficiently transforms a wide range of ketones into silyl ethers or secondary alcohols with high yields. The use of silanes as both substrates and activators eliminates the need for external additives.
Article
Chemistry, Organic
Monish Arbaz Ansari, Ganesh Kumar, Maya Shankar Singh
Summary: Here, we described an efficient method for the construction of highly functionalized diazirines from carbohydrazide and diazo-substituted hypervalent iodine reagents. The method is user applicable and easy to practice with unambiguous transformation conditions. Notably, D-glucose, menthol, aspirin, proline, and lithocholic acid were efficiently diazirinated. Furthermore, the method is mild, robust, and highly selective, converting various aryl, alkyl, benzyl, and heterocyclic hydrazides into the corresponding diazirine derivatives.
Article
Chemistry, Multidisciplinary
Ransong Ma, Zhoubin Deng, Ke-Hu Wang, Junjiao Wang, Danfeng Huang, Yingpeng Su, Yulai Hu, Xiaobo Lv
Summary: An efficient and novel photoinduced trifluoromethylation using CF3Br as a trifluoromethyl source is described. With commercially accessible fac-Ir(III)(ppy)3 as the catalyst, successful radical trifluoromethylation between O-silyl enol ether and CF3Br occurs. This method provides various alpha-CF3-substituted ketones with a broad substrate scope in good yields under mild reaction conditions.
Article
Chemistry, Organic
Xin He, Zhicheng Chen, Xianghui Zhu, Hao Liu, Yanjie Chen, Zhizhong Sun, Wenyi Chu
Summary: A metal and oxidant free photoredox catalyzed trifluoromethylation protocol of 2H-indazoles was developed using Eosin Y as the photocatalyst and recoverable ionic liquids as the solvents. Trifluoromethylated products were obtained in moderate to good yields under mild conditions. The reaction proceeded via a free-radical mechanism with broad substrate range, excellent regioselectivity, and good functional group tolerance. Furthermore, the protocol demonstrated its utility in the synthesis of a highly selective ligand for estrogen receptor beta (ER beta) and the drug granisetron. This protocol provides a mild and environmentally friendly solution for trifluoromethylation reaction.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Organic
Olesya V. Khoroshilova, Irina A. Boyarskaya, Aleksander V. Vasilyev
Summary: This study investigates the reaction of TMS ethers of CF3-benzyl alcohols and their heterocyclic analogues under the catalysis of strong acids, leading to the synthesis of alpha-(trifluoromethyl)styrenes and cis-/trans- 1,3-di(trifluoromethyl)indanes with high yields. The plausible reaction mechanisms, including the formation of CF3-benzyl carbocations as intermediates, are discussed.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Wei Wu, Shunli Wen, Xinyu Zhang, Qi Lin, Zhiqiang Weng
Summary: A highly efficient and regioselective synthesis of highly substituted 2-trifluoromethyl pyrrole derivatives is reported via a silver-catalyzed cyclization of vinyl azides with ethyl 4,4,4-trifluoro-3-oxobutanoate. Various types of alpha-(heteo)aryl, alkyl, alpha-aryl, and alpha,beta-disubstituted vinyl azides can participate in this transformation. The proposed reaction mechanism involves the addition of in situ generated 2H-azirine to the diketone species, followed by intramolecular addition, N-C-1 cleavage, and elimination.
Article
Chemistry, Organic
Luca Allievi, Sabrina Dhambri, Rongyu Sun, Mohamed Selkti, Marie-Isabelle Lannou, Geoffroy Sorin, Janick Ardisson
Summary: The new neurotrophic vibsane-type diterpenoid Vibsatin A was synthesized through a Conia-ene-derived 7-exo-dig cyclization to generate the bicyclic backbone and install all stereogenic centers.
Article
Engineering, Electrical & Electronic
Jinfeng Zhang, Qingguo Chen, Minghe Chi, Hongda Yang, Heqian Liu
Summary: Oil-paper insulation is the main insulation material of converter transformers, and the incorporation of Al2O3 nanoparticles in the oil-impregnated paper can effectively suppress space charge accumulation and improve breakdown field strength. The 2.5 wt% Al2O3 modified paper shows the best suppression effect on space charge accumulation.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2021)
Article
Computer Science, Artificial Intelligence
He Zhang, Qiuhong Chen, Pengbo Ni, Haibo Liang, Min Mao, Jialing Zou
Summary: This paper proposes a method for identifying the lithology of a drilled formation using element and gamma spectrum measurement, as well as establish an intelligent identification model. The field application shows that the accuracy of the proposed method can reach 90.9%, verifying the feasibility of using this approach for intelligent identification of formation lithology during drilling.
NEURAL COMPUTING & APPLICATIONS
(2022)
Article
Cell Biology
Huanjia Gao, Jeremy Bigalke, Enshe Jiang, Yuanyuan Fan, Bojun Chen, Qing-Hui Chen, Zhiying Shan
Summary: The study revealed that TNF alpha can induce inflammatory response in brain neurons and PVN of rats, with Dahl-S rats showing a more significant response to TNF alpha compared to SD rats. This increased inflammatory response in Dahl-S rats may indicate an underlying mechanism for enhanced pressor reactivity to salt intake in the Dahl-S rat model.
CELLULAR AND MOLECULAR NEUROBIOLOGY
(2022)
Article
Chemistry, Physical
Binbin Gou, Jianqi Qi, Chuanmin Meng, Liangbin Xiong, Yin Yu, Bin Ye, Qingyun Chen, Xiuxia Cao, Xiaofeng Guo
Summary: By adjusting the components of the γ-Al2O3 structure, AlON and MgAlON were formed in this study, with MgAlON showing a wider range for shock impedance adjustment compared to AlON. The simulation results indicate that the shock impedance of MgAlON can be completely matched with Fe samples in the pressure range of 0-20 GPa.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Inorganic & Nuclear
Abdelmoneim Bakur, Hongyun Lu, Tarig Elshaarani, Dafaallah Albashir, Anas Mohammed, Qihe Chen
Summary: This study introduces a green method for fabricating biocomposites using microbial glycolipids, showing strong antioxidant properties and effectiveness in inhibiting the growth of liver cancer cells.
JOURNAL OF CLUSTER SCIENCE
(2022)
Article
Engineering, Electrical & Electronic
Yecheng Zhang, Guohai Liu, Wenxiang Zhao, Huawei Zhou, Qian Chen, Mingji Wei
Summary: The article introduces a new method for diagnosing ISCF in low-speed PMSMs, which improves fault phase identification sensitivity by decomposing zero-sequence voltage vectors and extracting the voltage vector closest to the ISCF phase angle. Additionally, a method for extracting phase voltage from PWM duty-cycle control voltage is proposed to reduce errors caused by measuring zero-sequence voltage with three-phase balanced resistance. Experiments show that the online detection limit of ISCF in low-speed PMSMs is reduced from 5% to 1% (short-circuit ratio) using this method.
IEEE TRANSACTIONS ON TRANSPORTATION ELECTRIFICATION
(2021)
Article
Pharmacology & Pharmacy
Liuxiang Li, Xiaoxue Wang, Hongyu Zhang, Qingqing Chen, Huifei Cui
Summary: The study demonstrated that low anticoagulant heparin-iron significantly reduces anticoagulant activity, decreases hepcidin mRNA and IL-6 induced hepcidin levels in HepG2 cells, and lowers hepcidin expression through various pathways, leading to improved anemia in ACD mice with elevated serum hepcidin levels.
EUROPEAN JOURNAL OF PHARMACOLOGY
(2021)
Article
Mechanics
Shubiao Wang, Wenming Cheng, Run Du, Yupu Wang, Qingrong Chen
Summary: This paper discusses the flow-induced vibration of a freely vibrating trapezoidal cylinder with a mass ratio of 10 at low Reynolds numbers (Re=60-250). The responses of the trapezoidal cylinder are found to be different from square/circular cylinders under the same flow conditions, with double rise-ups in amplitudes and hydrodynamics forces observed in both VIV and galloping regimes. The phase differences and vortex modes in the wake are also different from square/circular cylinders, and seven flow branches are identified. The asymmetry of the trapezoidal cylinder to the inflow is identified as the direct cause, with hysteresis observed in both VIV and galloping regimes.
Article
Biotechnology & Applied Microbiology
Qingguo Chen, Yijing Li, Mei Liu, Baikang Zhu, Jun Mu, Zhi Chen
Summary: This study successfully removed lead and mercury from marine intertidal sediments using rhamnolipid biosurfactant (RB), with alkaline conditions favoring heavy metal removal. RB showed excellent performance in addressing this issue.
ENVIRONMENTAL TECHNOLOGY & INNOVATION
(2021)
Article
Architecture
Biao Zhou, Jiazhi Sun, Xukun Sun, Kai Wang, Chen Qingqing, Xuan Wang, Yajun Han
Summary: Chinese historic buildings with wooden structures are prone to fire disasters. The effects of hydrogen fluoride (HF) released during fire suppression on these buildings are unclear. Experimental results show that flame enhancement occurs at the early stage of fire suppression with various types of fire agents.
INTERNATIONAL JOURNAL OF ARCHITECTURAL HERITAGE
(2023)
Article
Biochemical Research Methods
Ping Yu, Xinxin Wang, Jian Ma, Qili Zhang, Qingwei Chen
Summary: This study investigated the chaperone-assisted soluble expression of high molecular weight chitinase chiZJ408 in Escherichia coli BL21 and its optimal conditions for activity. Results showed that introduction of the chaperone GroELS improved the correct folding and solubility of chitinase chiZJ408. Additionally, Mg(2+) and Ca2+ were found to significantly impact the activity of chitinase chiZJ408.
PREPARATIVE BIOCHEMISTRY & BIOTECHNOLOGY
(2022)
Article
Biochemical Research Methods
Min He, Jian Ma, Qingwei Chen, Qili Zhang, Ping Yu
Summary: The study successfully enhanced the production of PLP in E. coli by constructing a recombinant strain, and determined the optimal conditions for production, laying a good foundation for the efficient production of PLP.
PREPARATIVE BIOCHEMISTRY & BIOTECHNOLOGY
(2022)
Review
Chemistry, Applied
Yixin Wu, Yu Li, Yang Wang, Qian Liu, Qingguo Chen, Minghua Chen
Summary: Developing highly foldable batteries with no safety hazard is crucial for portable, wearable, and implantable electric devices. Solid-state batteries, particularly those based on PVDF electrolytes, show great potential, but also face challenges such as lower ionic conductivity and lack of reactive groups. Recent research has focused on gel polymer electrolytes and all solid polymer electrolytes based on PVDF to address these issues.
JOURNAL OF ENERGY CHEMISTRY
(2022)
Article
Education & Educational Research
Guangtian Zhu, Xiaoling Su, Juan Du, Qingwei Chen, Bolong Xiong, Feng-Kuang Chiang
Summary: The study explored the effects of different scaffolds on students' physics problem solving, with MAPS scaffold showing more effective results. Future research will focus on the application of dynamic figures in physics problem-solving.
INTERACTIVE LEARNING ENVIRONMENTS
(2023)
Article
Computer Science, Information Systems
Xuan Hua, Jungang Han, Chen Zhao, Haipeng Tang, Zhuo He, Qinghui Chen, Shaojie Tang, Jinshan Tang, Weihua Zhou
Summary: This paper presents a novel end-to-end ECG signal classification algorithm using a segmentation strategy and 1D Convolutional Neural Networks (CNN). The proposed method achieves high accuracy in classifying different types of heartbeats, reducing the workload of physicians. Experimental results demonstrate better performance compared to state-of-the-art methods.
MULTIMEDIA SYSTEMS
(2022)
