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Catalytically generated noncovalent ammonium dienolate:a versatile platform for the development of organocatalytic asymmetric cascade reactions

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Science China Chemistry 2024年第8期67卷 2524-2546页

作者： jun-Bing lin Dong-Sheng ji Peng-Fei Xu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000China Shaanxi Key Laboratory of Chemical Reaction Engineering College of Chemistry and Chemical EngineeringYan’an UniversityYan’an 716000China

Organocatalytic cascade reactions represent a powerful strategy for the rapid construction of complex chiral molecules with multiple stereocenters from simple substrates under mild conditions. The intriguing structural feature and diverse reactivity of catalytically generated dienolate species render them competent and versatile intermediates for the development of practical and valuable cascade reactions. Over the past years, a plethora of innovative and pioneering noncovalent ammonium dienolatemediated cascade reactions have been designed and implemented under the catalysis of chiral organocatalysts, making dienolate activation a general, robust, and complementary method for the functionalization of unsaturated carbonyl compounds and related substances. This review illustrates the recent advances in organocatalytic noncovalent ammonium dienolate-mediated cascade reactions(mainly from 2010 to 2023), including the cascade transformations of ammonium dienolates directly generated from unsaturated ketone/aldehyde, ester/lactone/azlactone, amide/lactam/pyrazolone/oxindole, and alkylidene nitrile compounds. The contents are arranged based on the reaction types of the ammonium dienolates, with an emphasis on cascade 2,5-, 3,5-, and 4,5-difunctionalizations of these intermediates. Furthermore, other cascade reactions involving the 1,3-, 2,3-, and even more complex 3,4,5-reactivities of ammonium dienolates were also discussed. The reaction pathway, reaction stereoinduction, and synthetic applications of the ammonium dienolate-mediated cascade reactions were highlighted throughout the article. As a stimulating and ever-growing research area, the organocatalytic noncovalent ammonium dienolate-mediated cascade reactions are expected to continue demonstrating their magic power for constructing chiral targets in the future and further expanding the boundaries of asymmetric catalysis.

关键词： organocatalysis asymmetric catalysis ammonium dienolate cascade reaction difunctionalization

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Multiple Normalized Solutions for Nonlinear Biharmonic Schr?dinger Equations in ■with L-Subcritical Growth

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Acta Mathematicae Applicatae Sinica 2024年

作者： jun WANG li WANG ji-xiu WANG Department of Mathematics Sun Yat-sen University College of Science East China Jiaotong University School of Mathematics and Statistics Hubei University of Arts and Science

In this article, we consider the existence of normalized solutions for the following nonlinear biharmonic Schr?dinger equations:■where c, ε > 0, N ≥ 5, λ ∈ R is a Lagrange multiplier and is unknown, h ∈ C（■N, [0, ∞）), f : R → R is continuous function satisfying L2-subcritical growth. When ε is small enough, we get multiple normalized solutions. Moreover, we also obtain orbital stability of the solutions.

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Artemsieverolactones A—H,Eight Guaiane-Type Sesquiterpenoid Trimers from Artemisia sieversiana

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Chinese Journal of Chemistry 2024年第10期42卷 1084-1092页

作者： Wei Dong Xiao-Yan Huang Tian-Ze li Yan-Mei Weng Chang-An Geng ji-jun Chen State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnan 650201China University of Chinese Academyof Sciences Beijing 100049China

Eight new guaiane-type sesquiterpenoid trimers,artemsieverolactones A—H,possessing unprecedented scaffolds via biocatalyzed[4+2]Diels−Alder cycloaddition reactions were identified from Artemisia *** structures were determined by comprehensive spectroscopic data,single-crystal X-ray diffraction analyses,and ECD *** terms of structure,artemsieverolactones A—H are first examples of sesquiterpenoid trimers from guaiane-type sesquiterpenoid through four different[4+2]Diels−Alder cycloaddition *** fibrosis assay suggested that five compounds exhibited activity against HSC-LX2 with IC_(50)values ranging from 37.8 to 117.1μmol/*** most active artemsieverolactone B(2)displayed significant inhibitory activity against HSC-LX2 with IC_(50)value of 37.8μmol/L,which was 3 times more active than the positive drug silybin(IC_(50),139.7μmol/L).Preliminary mechanism study revealed that artemsieverolactone B could inhibit the deposition of human collagen typeⅠ(ColⅠ),human hyaluronic acid(HA),and human laminin(HL)with IC_(50)values of 40.4μmol/L(Col I),55.1μmol/L(HL),47.3μmol/L(HA),which was 2 to 3-fold more potent than silybin.

关键词： Artemisia sieversiana Artemsieverolactones A-H Guaiane-type sesquiterpenoid trimers Antihepatic fibrosis Extracellular matrix Cancer NMR spectroscopy X-ray diffraction

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Artemordins A-S, Cadinane-Type Sesquiterpenoid Dimers from Artemisia ordosica and Their Antihepatoma Activities

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Chinese Journal of Chemistry 2024年第13期42卷 1493-1508页

作者： Yuan Wang Tian-Ze li Yun-Bao Ma Chang-An Geng Yong-Cui Wang ji-jun Chen State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnan 650201China University of Chinese Academy of Sciences Beijing 100049China

Nineteen new cadinane-involving sesquiterpenoid dimers,artemordins A-S(1-—19),together with 13 known SDs(20-32)were isolated from Artemisia *** structures and absolute configurations were established by comprehensive spectral analyses,X-ray single crystal diffraction,theoretical ECD,and NMR ***,artemordins A-F(1—6)were the first examples of two cadinane units constructed by unprecedented C-3−C-15′or C-3−C-13′single bond with an oxido-rearranged 6/5/6/6 fused ring system;artemordins G-K(7-11)were biogenetically connected by[4+2]cycloaddition reaction and artemordins G-J(7-10)possessed a novel 5/6/6/6/6/6/5-heptacyclic fused ring *** L-S(12-19)were formed by esterification,which involved three different types of *** assay suggested that the most active compounds,artemordins B and H(2 and 8),exhibited inhibitory activities on three hepatoma cell lines with IC50 values of 26.9 and 25.1μmol/L(HepG2),29.5 and 18.3μmol/L(Huh7),19.7 and 15.7μmol/L(SK-Hep-1).

关键词： Artemisia ordosica Artemordins A-s Cadinane-type sesquiterpenoid dimers Antihepatoma activities Terpenoids Natural products Cytotoxicity

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Effects of mid-passage gap with a variable surface angle on a turbine vane endwall’s aerothermal and film cooling performances

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Chinese Journal of Aeronautics 2024年第6期37卷 20-37页

作者： Zhiyu li Kaiyuan ZHANG Zhigang li jun li Institute of Turbomachinery Xi’an Jiaotong UniversityXi’an 710049China

The mid-passage gap is an inevitable structure in a vane passage due to turbine vanes being manufactured *** coolant from this gap is able to prevent hot mainstream ingression and provide cooling protection for the endwall.A novel idea of enlarging the endwall’s coverage area and reducing the endwall’s thermal load by applying the mid-passage gap with variable surface angles is carried out in this *** endwall’s aerothermal and film cooling performances under four mid-passage gap modes at three typical mass flow ratio conditions are numerically *** indicate that under the traditional mid-passage mode,the coolant flows into the mainstream with a perpendicular incidence angle and can’t stick to the ***,cooling failure occurs,and the endwall’s thermal load is badly *** film cooling level at the suction-side endwall is improved when applying the mid-passage gap of a 45surface angle due to the secondary vortex being *** addition,when applying the mid-passage gap of a 135surface angle,the horseshoe vortex is pushed away,and the coverage area at the pressure-side endwall is enlarged *** best film cooling performance is achieved when the upstream surface angle is 135and the downstream surface angle is 45due to the adiabatic film cooling effectiveness being increased at both the pressure-and suction-side *** the mass flow ratio is 1.5%,the coverage area is enlarged by 43%,and the area-averaged adiabatic film cooling effectiveness is increased by 37%,when compared with those under the traditional mid-passage mode.

关键词： Film cooling Heat transfer Surface angle Mid-passagegap Turbinevane endwall

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Event-triggered adaptive output feedback control for hyperbolic PDEs: swapping-based design

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Science China(Information Sciences) 2024年第5期67卷 327-328页

作者： Chunting ji Zhengqiang ZHANG Xue-jun XIE School of Engineering Qufu Normal University Institute of Automation Qufu Normal University

Partial differential equations(PDEs) characterize transport phenomena and fluid flow, and common cases include heat exchangers and road traffic [1]. Recently, scholars have become enthusiastic about event-triggered control(ETC) of hyperbolic PDEs, primarily because it can help conserve computing and communication resources. For example,Ref. [2] presented an output feedback ETC scheme for 2 × 2hyperbolic PDEs.

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Electronic engineering of Co-Ru diatomic sites and Ru nanoparticles for synergistic promotion of hydrogen evolution

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Nano Research 2024年第5期17卷 3714-3723页

作者： Wei Zhang Cong li Yongyong Cao jun-Yang ji Zhao-Chen li Zheng Niu Hongwei Gu Pierre Braunstein jian-Ping Lang College of Chemistry Chemical Engineering and Materials ScienceSoochow UniversitySuzhou 215123China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China College of Biological Chemical Science and EngineeringJiaxing UniversityJiaxing 314001China Universitéde Strasbourg-CNRS Institut de Chimie(UMR 7177 CNRS)4 rue Blaise Pascal-CS 9003267081 StrasbourgFrance

The coexistence of multi-component active sites like single-atom sites,diatomic sites(DAS)and nanoclusters is shown to result in superior performances in the hydrogen evolution reaction(HER).Metal diatomic sites are more complex than single-atom sites but their unique electronic structures can lead to significant enhancement of the HER *** the synthesis and identification of DAS is usually challenging,we report a simple access to a diatomic catalyst by anchoring Co-Ru DAS on nitrogen-doped carbon supports along with Ru nanoparticles(NPs).Experimental and theoretical results revealed the atomic-level characteristics of Co-Ru sites,their strong electronic coupling and their synergy with Ru NPs within the *** unique electronic structure of the catalyst resulted in an excellent HER activity and stability in alkaline *** work provides a valuable insight into a widely applicable design of diatomic catalysts with multi-component active sites for highly efficient HER electrocatalysis.

关键词： Co-Ru diatomic sites Ru nanoparticles multiple active sites synergistic effect hydrogen evolution reaction

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A practical synthesis of (-)fosfomycin from its enantiomer

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Chinese Chemical Letters 2008年第11期19卷 1297-1300页

作者： Meng Zhang Zheng Yu ji jun li Da li Yin Beijing Collab Pharma Co. Ltd. Beijing 102600 China Institute of Materia Medica Peking Union Medical College Beijing 100050 China

（＋）-cis-（1S, 2R）-Epoxypropylphosphonic acid, the enantiomer of fosfomycin, which is the industrial side-product in the preparation of the antibiotic fosfomycin, was converted into （-）fosfomycin by a seven-step procedure. The esterification of the dihydroxyphosphonic intermediate was the key step. The title compound was obtained in good yield and its optical purity was up to the medicine quality standard of Chinese Pharmacopoeia.

关键词： Fosfomycin Enantiomer Phosphonate

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Safflower Yellow Inhibits Progression of Hepatocellular Carcinoma by Modulating Immunological Tolerance via FAK Pathway

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Chinese Journal of Integrative Medicine 2024年第4期30卷 339-347页

作者： ji Hua-feng YANG Zi-qiang HAN jun-jun li He-fang jiN Zhao-qing CHEN Wei-qing CHEN Fei-hua GONG Mou-chun Department of General Surgery First People's Hospital of Hangzhou Lin'an DistrictHangzhou(311300)China

Objective To explore the anti-tumor effect of safflower yellow(SY)against hepatocellular carcinoma(HCC)and the underlying potential *** An in vitro model was established by mixing Luc-Hepa1-6 cells and CD3^(+)CD8^(+)T cells,followed by adding programmed cell death protein 1(PD-1)antibody(Anti-mPD-1)with or without *** apoptosis was detected by flow cytometry and the level of inflammatory cytokines was determined by enzyme-linked immunosorbent *** protein levels of programmed cell death 1 ligand 1(PD-L1),chemokine ligand(CCL5),C-X-C motif chemokine ligand 10(CXCL10)were measured by Western *** in situ animal model was established in mice followed by treatment with anti-mPD-1 with or without *** imaging was monitored with an AniView 100 imaging *** establish the FAK-overexpressed Luc-Hepa1-6 cells,cells were transfected with adenovirus containing pcDNA3.1-FAK for 48 *** The fluorescence intensity,apoptotic rate,release of inflammatory cytokines,and CCL5/CXCL10 secretion were dramatically facilitated by anti-mPD-1(Plitated release of inflammatory cytokines,inactivated PD-1/PD-L1 axis,and increased CCL5/CXCL10 secretion were observed in Anti-mPD-1 treated mice(Plitating apoptosis and inflammatory cytokine releasing,suppressing the PD-1/PD-L1 axis,and inducing the CCL5/CXCL10 secretion in Anti-mPD-1 treated mixture of Luc-Hepa1-6 cells and CD3+CD8+T cells were abolished by FAK overexpression(P<0.01).Conclusion SY inhibited the progression of HCC by mediating immunological tolerance through inhibiting FAK.

关键词： hepatocellular carcinoma safflower yellow Chinese medicine tumor microenvironment programmed cell death protein 1 focal adhesion kinase

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Mechanism of microarc oxidation on AZ91D Mg alloy induced byβ-Mg_(17)Al_(12) phase

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International Journal of Minerals,Metallurgy and Materials 2024年第4期31卷 712-724页

作者： Dajun Zhai Xiaoping li jun Shen College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

This work proposed a strategy of indirectly inducing uniform microarc discharge by controlling the content and distribution ofβ-Mg_(17)Al_(12)phase in AZ91D Mg *** kinds of nano-particles(ZrO_(2)and TiO_(2))were designed to be added into the substrate of Mg alloy by friction stir processing(FSP).Then,Mg alloy sample designed with different precipitated morphology ofβ-Mg_(17)Al_(12)phase was treated by microarc oxidation(MAO)in Na_(3)PO_(4)/*** characteristics and performance of the MAO coating was analyzed using scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),contact angle meter,and potentiodynamic *** was found that the coarseα-Mg grains in extruded AZ91D Mg alloy were refined by FSP,and theβ-Mg_(17)Al_(12)phase with reticular structure was broken and *** nano-ZrO_(2)particles were pinned at the grain boundary by FSP,which refined theα-Mg grain and promoted the precipitation ofβ-Mg_(17)Al_(12)phase in *** effectively inhibited the“cascade”phenomenon of microarcs,which induced the uniform distribution of discharge *** MAO coating on Zr-FSP sample had good wettability and corrosion ***,TiO_(2)particles were hardly detected in the coating on TiFSP sample.

关键词： AZ91D Mg alloy microarc oxidation friction stir processing ZrO_(2) TiO_(2) β-Mg_(17)Al_(12)

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