检索结果-南通市图书馆

Nickel-Catalyzed Regiodivergent Acylzincation of Styrenes with Organozincs and CO

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第6期42卷 599-604页

作者： Chenglong Wang Ning Liu Xianqing Wu Jingping Qu Yifeng Chen key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and molecular Engineering Feringa Nobel Prize Scientist Joint Research CenterFrontiers Science Center for Materiobiology and Dynamic ChemistrySchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai200237 China Dedicated to the Special Issue of C1 Chemistry.

Transition metal-catalyzed carbometallation of unsaturated hydrocarbons constitutes one of the most efficient synthetic methodologies for the construction of C—C ***,the incorporation of organometallic reagent with the CO gas as a nucleophilic acyl synthon could enable the acylmetallation reaction,which greatly increases the horizon of carbometallation ***,we report a nickel-catalyzed regiodivergent acylzincation of o-cyano cinnamate ester and o-cyano styrene,in which the cyano moiety intramolecularly captures zinc intermediates to trigger the tandem cyclization *** protocol features mild conditions,broad substrate scope and excellent functional group tolerance,thus affording a diverse array of highly functionalized carbocyclic compounds.

关键词： Carbonylation Carbometallation Styrene Nickel Cyclization

Synergistic silver-mediated and palladium-catalyzed nondirected olefination of aryl C–H bond: quick access to multi-substituted aryl olefins

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

science China Chemistry 2024年第3期67卷 882-889页

作者： Jian Yao Lili Shao Xiaohong Huo Xiaoming Wang Shanghai key Laboratory for molecular Engineering of Chiral Drugs Frontiers Science Center for Transformative MoleculesSchool of Chemistry and Chemical EngineeringShanghai Jiao Tong UniversityShanghai 200240China State key Laboratory of Organometallic Chemistry Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 20032China School of Chemistry and Materials science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China

Transition metal-catalyzed olefination of aryl C-H bond is a powerful tool for the synthesis of alkenes. While the Pd-catalyzed oxidative C-H olefination of arenes, also known as Fujiwara-Moritani reaction, has been established as one of the most efficient methods, the substrates are largely limited to terminal olefins with electron-withdrawing group(s). Herein, we report a synergistic silver-mediated and palladium-catalyzed non-directed C-H olefination of arenes with vinyl(pseudo)halides, which offers a complementary strategy to the typical Fujiwara-Moritani reaction. The reactions proceeded well for a variety of halogenated arenes, heteroarenes, and olefin substrates, providing an efficient access to various multi-substituted aryl olefins, including trisubstituted/tetrasubstituted olefins and several complex olefins derived from medicines or natural products. Mechanistic studies indicated a bimetallic Pd/Ag cooperation is operative in the catalysis, i.e., the reaction is initiated by aryl C-H bond cleavage via ligation with phosphine/Ag species, followed by transferring of the aryl moiety to a vinyl palladium intermediate,which is in turn formed by oxidative addition of vinyl(pseudo)halide to a Pd complex. This method enables the synthesis of a wide range of challenging multi-substituted vinyl products from simple arenes(directing-group free) in a streamlined and controllable fashion.

关键词： direct C–H olefination multi-substituted aryl alkenes bimetallic Pd/Ag cooperation C–H functionalization

Enhancing the deep-red/near-infrared fluorescence of higher rylene diimides via the chalcogen-annulation strategy

在线全文

学校读者我要写书评

暂无评论

science China Chemistry 2024年第4期67卷 1324-1333页

作者： Kai Chen Xiao Chen Ke Hu Yilun Zhao Yujian Liu Guogang Liu Jinquan Chen Wei Jiang Zhigang Shuai Da-Hui Qu Zhaohui Wang key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and molecular Engineering Feringa Nobel Prize Scientist Joint Research CenterFrontiers Science Center for Materiobiology and Dynamic ChemistryInstitute of Fine ChemicalsSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China key Laboratory of Organic Optoelectronics and molecular Engineering Department of ChemistryTsinghua UniversityBeijing 100084China State key Laboratory of Precision Spectroscopy East China Normal University500 Dongchuan RoadShanghai 200241China

Deep-red/near-infrared fluorescence is highly suitable for bioimaging owing to its ability to deeply penetrate tissues,organs,and live ***,developing organic fluorophores with high deep-red/near-infrared fluorescence quantum yield(Φ_(FL))and fluorescent brightness remain a significant challenge owing to the energy gap ***,we developed a straightforward and effective chalcogen-annulation strategy by introducing O,S and Se into the bay region of TDI and QDI fluorophores,realizing the increase ofΦFLand fluorescent brightness up to 10 *** our best knowledge,this study potentially stands as the pioneering instance showcasing the anti-heavy-atom effect of chalcogens,and the absoluteΦFL(93%)and fluorescent brightness(128,200 cm^(-1)mol^(-1)L)of Se-TDI is among top deep-red/near-infrared organic fluorophores currently *** femtosecond transient absorption(fs-TA)measurements show the absence of obvious changes of the excited state lifetime after the introduction of chalcogens in TDI and QDI fluorophores,indicating that intersystem crossing(ISC)can be neglected in TDI and QDI *** calculations further reveal the chalcogen-annulation strategy increase the radiative rates and reduce the reorganization energy of several accepting modes at the ground state in TDI fluorophores,leading to the suppression of internal conversion(IC)*** chalcogen-annulation strategy,which effectively increases the Φ_(FL)and restricts the IC processes,while remaining unaffected by the heavy-atom effect,offers novel insights and theoretical support for the design and synthesis of deep-red/near-infrared organic fluorophores with high Φ_(FL)and fluorescent brightness.

关键词： π-extended rylene diimides chalcogen-annulation strategy deep-red/near-infrared fluorescence

A biocompatible Horner-Wadsworth-Emmons(HWE)reaction triggered by a bioorthogonal proximity-induced platform

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第8期35卷 217-220页

作者： Yayue Wang Haojie Yang Jie Li Qiao Kong Siming Zhou Hongbao Sun Lili Pan Qiyong Gong Ping Feng Haoxing Wu Department of Radiology and Huaxi MR Research center(HMRRC) Functional and Molecular Imaging Key Laboratory of Sichuan ProvinceFrontiers Science Center for Disease Related Molecular NetworkWest China HospitalSichuan UniversityChengdu 610041China key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province Sichuan UniversityChengdu 610041China Department of Nuclear Medicine Laboratory of Clinical Nuclear MedicineWest China HospitalSichuan UniversityChengdu 610041China Reseacrch Unit of Psychoradiology Chinese Academy of Medical SciencesChengdu 610041China Department of Pharmacy West China HospitalSichuan UniversityChengdu 610041China Clinical Trial center and National Medical Products Administration key Laboratory for Clinical Research and Evaluation of Innovative Drugs West China HospitalSichuan UniversityChengdu 610041China

Here,we present a novel bioorthogonal platform that enables precise positioning of attached moieties in close proximity,thereby facilitating the discovery and optimization of biocompatible *** this platform,we achieve a Horner-Wadsworth-Emmons(HWE)reaction under physiological conditions,generating a fluorophore in situ with a yield of up to 93%.This proximity platform should facilitate the discovery of various types of biocompatible reactions,making it a versatile tool for biomedical applica-tions.

关键词： Biocompatible reactions Horner-Wadsworth-Emmons reaction Bioorthogonal reactions Tetrazines Proximity effects

Rational surface charge engineering of haloalkane dehalogenase for boosting the enzymatic performance in organic solvent solutions

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第1期65卷 276-285页

作者： Yin Wu Yan Sun Department of Biochemical Engineering School of Chemical Engineering and Technology and Key Laboratory of Systems Bioengineering and Frontiers Science Center for Synthetic Biology(Ministry of Education)Tianjin UniversityTianjin 300350China

Biocatalysis in organic solvents(OSs)has numerous important applications,but native enzymes in OSs often exhibit limited catalytic ***,we proposed a computation-aided surface charge engineering strategy to improve the catalytic performance of haloalkane dehalogenase DhaA in OSs based on the energetic analysis of substrate binding to the DhaA *** variants with enhanced OS resistance were obtained by replacing negative charged residues on the surface with positive charged residue(Arg).Particularly,a four-substitution variant E16R/E93R/E121R/E257R exhibited the best catalytic performance(five-fold improvement in OS resistance and seven-fold half-life increase in 40%(vol)dimethylsulfoxide).As a result,the overall catalytic performance of the variant could be at least 26 times higher than the wild-type *** spectroscopy and molecular dynamics simulation studies revealed that the residue substitution mainly enhanced OS resistance from four aspects:(a)improved the overall structural stability,(b)increased the hydrophobicity of the local microenvironment around the catalytic triad,(c)enriched the hydrophobic substrate around the enzyme molecule,and(d)lowered the contact frequency between OS molecules and the catalytic *** findings validate that computationaided surface charge engineering is an effective and ingenious rational strategy for tailoring enzyme performance in OSs.

关键词： Surface charge engineering Organic solvent resistance molecular dynamics simulation Haloalkane dehalogenase

Strengthening and toughening styrene-butadiene rubber by mechanically interlocked cross-links

在线全文

学校读者我要写书评

暂无评论

science China Chemistry 2024年第10期67卷 3414-3422页

作者： Yuanhao Wang Li Yang Lin Cheng Jun Zhao Ruixue Bai Wenbin Wang Shaolei Qu Zhaoming Zhang Wei Yu Xuzhou Yan School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative MoleculesShanghai Key Laboratory of Electrical Insulation and Thermal AgingShanghai Jiao Tong University

Styrene-butadiene rubber(SBR) is an indispensable material in modern society, and the necessity for enhanced mechanical properties in SBR persists, particularly to withstand the rigors of challenging environmental conditions. To surmount the limitations of conventional cross-linking modes, mechanical bonds stabilized by host-guest recognition are incorporated as the cross-linking points of SBR to form mechanically interlocked networks(MINs). Compared with covalently cross-linked network, the representative MIN exhibits superior mechanical performance in terms of elongation(1392%) and breaking strength(4.6 MPa), whose toughness has surged by 17 times. Dissociation of host-guest recognition and subsequent sliding motion provide an effective energy dissipation mechanism, and the release of hidden length is also beneficial to enhance ***, the introduction of the rotaxane cross-links made the network more pliable and possess damping and elastic properties, which can return to initial state with one minute rest interval. We aspire that this direct introduction method can serve as a blueprint, offering valuable insights for the enhancement of mechanical properties in conventional commercial polymer materials.

关键词： mechanically interlocked molecules host-guest chemistry styrene-butadiene rubber mechanical properties dynamic materials

Efficient wide-bandgap perovskite solar cells with open-circuit voltage deficit below 0.4 V via hole-selective interface engineering

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science China Chemistry 2024年第6期67卷 2102-2110页

作者： Xiaoyu Ji Shuo Zhang Furong Yu Huidong Zhang Liqing Zhan Yue Hu Wei-Hong Zhu Yongzhen Wu key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and molecular Engineering Shanghai Key Laboratory of Functional Materials ChemistryFrontiers Science Center for Materiobiology and Dynamic ChemistryInstitute of Fine ChemicalsSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai200237China School of Chemistry University of EdinburghKing’s BuildingsEdinburghEH93FJUK

Wide-bandgap mixed-halide perovskite solar cells(WBG-PSCs)are promising top cells for efficient tandem photovoltaics to achieve high power conversion efficiency(PCE)at low ***,the open-circuit voltage(V_(OC))of WBG-PSCs is still unsatisfactory as the V_(OC)-deficit is generally larger than 0.45 ***,we report a buried interface engineering strategy that substantially improves the V_(OC)of WBG-PSCs by inserting amphiphilic molecular hole-selective materials featuring with a cyanovinyl phosphonic acid(CPA)anchoring group between the perovskite and *** assembly and redistribution of CPA-based amphiphilic molecules at the perovskite-substrate buried interface not only promotes the growth of a low-defect crystalline perovskite thin film,but also suppresses the photo-induced halide phase *** energy level alignment between wide-bandgap perovskite and the hole-selective layer is further improved by modulating the substituents on the triphenylamine donor moiety(methoxyls for MPA-CPA,methyls for Me PA-CPA,and bare TPA-CPA).Using a 1.68 e V bandgap perovskite,the Me PA-CPA-based devices achieved an unprecedentedly high V_(OC)of 1.29 V and PCE of 22.3%under standard AM 1.5 *** V_(OC)-deficit(<0.40 V)is the lowest value reported for *** work not only provides an effective approach to decreasing the V_(OC)-deficit of WBG-PSCs,but also confirms the importance of energy level alignment at the charge-selective layers in PSCs.

关键词： cyanovinyl phosphonic acid energy level alignment hole-selective material open-circuit voltage wide-bandgap perovskite

Phosphorylation of ZmAL14 by ZmSnRK2.2 regulates drought resistance through derepressing ZmROP8 expression

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2024年第7期66卷 1334-1350页

作者： Yalin Wang Jinkui Cheng Yazhen Guo Zhen Li Shuhua Yang Yu Wang Zhizhong Gong State key Laboratory of Plant Environmental Resilience Frontiers Science Center for Molecular Design BreedingCollege of Biological SciencesChina Agricultural UniversityBeijing 100193China center for Crop Functional Genomics and molecular Breeding China Agricultural UniversityBeijing 100193China College of Life sciences Institute of Life Science and Green DevelopmentHebei UniversityBaoding 071002China

Drought stress has negative effects on crop growth and *** of transcription factors that regulate the expression of drought-responsive genes is critical for understanding the transcriptional regulatory networks in response to drought,which facilitates the improvement of crop drought ***,we identified an Alfin-like(AL)family gene ZmAL14 that negatively regulates drought *** of ZmAL14 exhibits susceptibility to drought while mutation of ZmAL14 enhances drought *** abscisic acid(ABA)-activated protein kinase ZmSnRK2.2 interacts and phosphorylates ZmAL14 at T38 *** of ZmSnRK2.2 gene decreases drought resistance of maize.A dehydration-induced Rho-like small guanosine triphosphatase gene ZmROP8 is directly targeted and repressed by *** of ZmAL14 by ZmSnRK2.2 prevents its binding to the ZmROP8 promoter,thereby releasing the repression of ZmROP8 *** of ZmROP8 stimulates peroxidase activity and reduces hydrogen peroxide accumulation after drought ***,our study indicates that ZmAL14 is a negative regulator of drought resistance,which can be phosphorylated by ZmSnRK2.2 through the ABA signaling pathway,thus preventing its suppression on ZmROP8 transcription during drought stress response.

关键词： ZmAL14 drought tolerance transcription factor maize

Genetic variation in a heat shock transcription factor modulates cold tolerance in maize

在线全文

学校读者我要写书评

暂无评论

molecular Plant 2024年第9期17卷 1423-1438页

作者： Lei Gao Lingling Pan Yiting Shi Rong Zeng Minze Li Zhuoyang Li Xuan Zhang Xiaoming Zhao Xinru Gong Wei Huang Xiaohong Yang Jinsheng Lai Jianru Zuo Zhizhong Gong Xiqing Wang Weiwei Jin Zhaobin Dong Shuhua Yang State key Laboratory of Plant Environmental Resilience Frontiers Science Center for Molecular Design BreedingCollege of Biological SciencesCenter for Crop Functional Genomics and Molecular BreedingChina Agricultural UniversityBeijing 100193China State key Laboratory of Maize Bio-breeding National Maize Improvement CenterFrontiers Science Center for Molecular Design BreedingDepartment of Plant Geneticsand BreedingChinaAgricultural UniversityBeijingChina State key Laboratory of Plant Genomics and National Plant Gene Research center Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing100101China

Understanding how maize(Zea mays)responds to cold stress is crucial for facilitating breeding programs of cold-tolerant *** extensive utilization of the genome-wide association study(GWAs)approach for exploring favorable natural alleles associated with maize cold tolerance,few studies have successfully identified candidate genes that contribute to maize cold *** this study,we used a diverse panel of inbred maize lines collected from different germplasm sources to perform a GWAS on var-iations in the relative injured area of maize true leaves during cold stress-a trait very closely correlated with maize cold *** identified HsF21,which encodes a B-class heat shock transcription factor(HSF)that positively regulates cold tolerance at both the seedling and germination *** varia-tions in the promoter of the cold-tolerant HSF21Hap1 allele led to increased HSF21 expression under cold stress by inhibiting binding of the basic leucine zipper bziP68 transcription factor,a negative regulator of cold *** integrating transcriptome deep sequencing,DNA affinity purification sequencing,and targeted lipidomic analysis,we revealed the function of HsF21 in regulating lipid metabolism homeo-stasis to modulate cold tolerance in *** addition,we found that HsF21 confers maize cold tolerance without incurring yield ***,this study establishes HsF21 as a key regulator that en-hances cold tolerance in maize,providing valuable genetic resources for breeding of cold-tolerant maize varieties.

关键词： heat shock factor HSF21 cold tolerance natural variation bZiP68 lipid metabolism maize