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Yakun Wang Qinghe Gao Nan Li Yifan Chen Jingwen Cui Feiyu Gao Qingwei Meng 《Tetrahedron》2018,74(30):4126-4133
A facile and efficient protocol for α-benzoyloxylation and α-hydroxylation of β-keto amides by phase-transfer catalysis is presented. This methodology provides mild and practical access to a variety ofα-oxygenated β-keto amides. Furthermore, α-benzoyloxylation products can be easily converted into α-hydroxylation compounds, which are useful synthetic precursors of biological targets. 相似文献
213.
A series of polystyrene-divinylbenzene cross-linked resin (PS)–supported zinc chloride catalysts were prepared in this study. They can efficiently catalyze the solventless cycloaddition of cyclohexene oxide with carbon dioxide in the presence of tetrabutylammonium bromide (TBAB) as cocatalyst under relatively mild reaction conditions. The catalyst is composed of carrier, connecting arm, ligand, and active ingredient. The connecting arms of different lengths can significantly affect the catalytic activity. Among these catalysts, the one using diethylene glycol as connecting arm and 2-aminopyridine as ligand, named PS-DEG-2ap-ZnCl2, showed the optimal catalytic performance. The yield of cyclohexene carbonate was 95.18% calculated by gas chromatographic analysis under the optimal conditions (393 K, 5 MPa, 6 h). Moreover, the catalyst showed good stability and reusability. From the viewpoint of industrial application, the catalyst is attractive because of its excellent catalytic efficiency on the synthesis of cyclohexene carbonate. 相似文献
214.
Chitosan/Ce(IV) redox polymerization‐based amplification for detection of DNA point mutation 下载免费PDF全文
Yanjun Cui Tianwei Tan Jing Yang 《Journal of polymer science. Part A, Polymer chemistry》2016,54(13):1929-1937
Polymerization‐based signal amplification, a technique developed for use in rapid diagnostic tests, hinges on the ability to localize initiators as a function of interfacial binding events. We report here a new DNA detection method in which polymer growth in redox‐polymerization is used as a means to amplify detection signals. The introduction of biotin‐labeled chitosan (biotin‐CS) with highly dense amino groups into the polymerization amplification as macromolecular reducing agent, beneficially simplifies amplification operation, as well as, provides a large amount of initiation points to improve the sensitivity of detection. DNA hybridization, SA and biotin binding reactions led to the attachment of CS on a solid surface where specific DNA sequences were located. With the addition of the mixture containing monomer AM, crosslinker PEGDA and oxidant CAN onto the CS location, the growth of polymer films was triggered to render the corresponding spots readily distinguishable to the naked eye. Direct visualization of 0.21 fmol target DNA molecules of interest was demonstrated. Non‐small cell lung cancer p53 sequence was further selected as a proof‐of‐principle to detect DNA point mutation. The proposed method exhibited an efficient amplification performance for molecule detection, and paved a new way for visual diagnosis of biomolecules. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1929–1937 相似文献
215.
Xiaoxiao Xu Prof. Caihong Fang Ting Bi Zhiqing Cui Guili Zhao Xiaomin Jiang Jinwu Hu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(47):10787-10794
Plasmonic nanostructures with large absorption areas under resonant excitation have been utilized extensively in photon-assisted applications. In this work, dodecahedral Au nanobowls were first prepared by an easy and template-free method only through the introduction of H2PtCl6 and I− during the growth procedure. The Au nanobowls show electron-field enhancement due to the high curvature of the bowl edge, the open region, and dodecahedral morphology. Au/Pt nanobowls, which couple plasmonic Au and catalytic Pt, were then constructed as plasmonic electrocatalysts for methanol oxidation. The mass activity reached 497.6 mA mg−1 under visible-light illumination, which is 1.9 times that measured in the dark. Simultaneously, the electrocatalytic stability is also greatly improved under light excitation. The enhanced properties of the plasmonic Au/Pt electrocatalysts are ascribed to the synergistic effect of the plasmon-enhanced photothermal and hot-carrier effects on the basis of experimental investigations. This work thus offers an effective methodology to construct efficient plasmonic electrocatalysts for fuel cells. 相似文献
216.
Prof. Caihong Fang Guili Zhao Zijun Zhang Qian Ding Nan Yu Zhiqing Cui Ting Bi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(30):7351-7358
Multifunctional metal nanostructures with a hollow feature, especially for nanoframes, are highly attractive owing to their high surface-to-volume ratios. However, pre-grown metal nanocrystals are always involved during the preparation procedure, and a synthetic strategy without the use of a pre-grown template is still a challenge. In this article, a template-free strategy is reported for the preparation of novel AuPt alloy nanoframes through simply mixing HAuCl4 and H2PtCl6 under mild conditions. The alloy nanostructures show a bipyramid-frame hollow architecture with the existence of only the ten ridges and absence of their side faces. This is the first report of bipyramid-like nanoframes and a template-free method under mild conditions. This configuration merges the plasmonic features of Au and highly active catalytic sites of Pt in a single nanostructure, making it an ideal multifunctional platform for catalyzing and monitoring the catalytic reaction in real time. The superior catalytic activity is demonstrated by using the reduction of nitrobenzene to the corresponding aminobenzene as a model reaction. More importantly, the AuPt nanoframes can track the reduction process on the basis of the SERS signals of the reactants, intermediates, and products, which helps to reveal the reaction mechanism. In addition, the AuPt nanoframes show much higher electrocatalytic properties toward the methanol oxidation reaction than commercial Pt/C electrocatalysts. 相似文献
217.
Yunxia Huang Shuaipeng Ge Xiaojuan Chen Zhongcheng Xiang Xinran Zhang Ruoxuan Zhang Yimin Cui 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(62):14117-14122
The design of electrode materials with rational core/shell structures is promising for improving the electrochemical properties of supercapacitors. Hence, hierarchical FeCo2S4@FeNi2S4 core/shell nanostructures on Ni foam were fabricated by a simple hydrothermal method. Owing to their structure and synergistic effect, they deliver an excellent specific capacitance of 2393 F g−1 at 1 A g−1 and long cycle lifespan as positive electrode materials. An asymmetric supercapacitor device with FeCo2S4@FeNi2S4 as positive electrode and graphene as negative electrode exhibited a specific capacitance of 133.2 F g−1 at 1 A g−1 and a high energy density of 47.37 W h kg−1 at a power density of 800 W kg−1. Moreover, the device showed remarkable cycling stability with 87.0 % specific-capacitance retention after 5000 cycles at 2 A g−1. These results demonstrate that the hierarchical FeCo2S4@FeNi2S4 core/shell structures have great potential in the field of electrochemical energy storage. 相似文献
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219.
In this paper, the notion of almost fuzzy compactness is defined in L-fuzzy topological spaces by means of inequality, where L is a completely distributive DeMorgan algebra. Its properties are discusse... 相似文献
220.