检索结果-南通市图书馆

Chinese Journal of Chemistry 2024年第8期42卷 873-878页

作者： Jian Long Zhiwu Lu Xiao-Lin Li Peng Xue Wen-Bo Liu engineering research center of organosilicon compounds&materials(ministry of education)and College of Chemistry and Molecular Sciences Wuhan UniversityWuhanHubei430072 China

Comprehensive Summary,The azepine ring is a prominent structural scaffold in biologically significant molecules. In this study, we present a Ni(II)-catalyzed asymmetric difunctionalization of alkynes, involving intermolecular regioselective arylation and intramolecular nitrile addition, enabling the synthesis of enantioenriched azepine derivatives. This reaction simultaneously installs an all-carbon quaternary stereocenter and introduces an unprotected imine functionality, showing great promise for subsequent transformations. The reaction exhibits good tolerance toward various functional groups, resulting in high yields and enantioselectivities. The synthetic utility of this methodology is further demonstrated through gram-scale synthesis and product derivatization. This research offers an efficient approach to the synthesis of seven-membered nitrogen heterocycles.

关键词： Nickel Asymmetric catalysis N-Heterocycles Alkyne functionalization Quaternary centers

Synthesis of Organofluorine compounds with Acylsilanes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第8期42卷 887-902页

作者： Youyuan Guo Gang Zhou Xiao Shen The Institute for Advanced Studies Engineering Research Center of Organosilicon Compounds&MaterialsMinistry of EducationWuhan University299 Bayi RoadWuhanHubei430072 China

Comprehensive Summary,Organofluorine compounds are central in synthetic chemistry,medicinal chemistry and material chemistry.In this review,we summarize the investigations on the synthesis of organofluorine compounds with acylsilanes.For the non-fluorinated acylsilanes,the in situ generation of difluoroenoxysilanes from the reactions of the acylsilanes with trifluoromethylation reagents is the major pathway,leading to the facile preparation of variousα,α-difluoroketones.For the fluoroalkylacylsilanes,apart from the in situ generation of difluoroenoxysilanes through anion Brook rearrangement,radical Brook rearrangement of the photoexcited acylsilanes and the selective control of reactivities of the biradicals pave the way for the synthesis of a variety of organofluorine compounds.In general,most of these reactions gave racemic products,and the asymmetric synthesis of organofluorine compounds with acylsilanes is still rare,which would be a future.

关键词： Acylsilanes Organofluorine compounds Brook rearrangement Radical rearrangement β-Fluoride elimination Asymmetric catalysis Photocatalysis Defluoroalkylation

Solid Bi_(2)O_(3)-derived nanostructured metallic bismuth with high formate selectivity for the electrocatalytic reduction of CO_(2)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and materials 2024年第4期31卷 803-811页

作者： Xiaoyan Wang Safeer Jan Zhiyong Wang Xianbo Jin College of Chemistry and Molecular Sciences Hubei Key Laboratory of Electrochemical Power SourcesWuhan UniversityWuhan 430072China engineering research center of organosilicon compounds&materials Ministry of EducationWuhan 430072China

CO_(2) electrochemical reduction(CO_(2)ER)is an important research area for carbon neutralization.However,available catalysts for CO_(2) reduction are still characterized by limited stability and activity.Recently,metallic bismuth(Bi)has emerged as a promising catalyst for CO_(2) ER.Herein,we report the solid cathode electroreduction of commercial micronized Bi2O3as a straightforward approach for the preparation of nanostructured Bi.At-1.1 V versus reversible hydrogen electrode in a KHCO3aqueous electrolyte,the resulting nanostructure Bi delivers a formate current density of~40 mA·cm^(-2) with a current efficiency of~86%,and the formate selectivity reaches97.6% at-0.78 V.Using nanosized Bi2O3as the precursor can further reduce the primary particle sizes of the resulting Bi,leading to a significantly increased formate selectivity at relatively low overpotentials.The high catalytic activity of nanostructured Bi is attributable to the ultrafine and interconnected Bi nanoparticles in the nanoporous structure,which exposes abundant active sites for CO_(2) electrocatalytic reduction.

关键词： bismuth carbon dioxide electrocatalysis formate solid electroreduction

维普期刊数据库

Molecular origin for pH-responsive wormlike micelles of zwitterionic surfactants triggered by aromatic acid derivatives

在线全文

学校读者我要写书评

暂无评论

ChemPhysMater

ChemPhysMater 2024年第2期3卷 230-238页

作者： Shuo Lu Yonghang Cheng Jinfeng Dong Xuefeng Li engineering research center of organosilicon compounds&materials Ministry of EducationCollege of Chemistry and Molecular SciencesWuhan UniversityWuhan 430072China

Introduction of aromatic acid derivatives(AADs)into zwitterionic surfactants is an efficient method to prepare wormlike micelles with pH-controllable viscosity;however,the coincident molecular origin of AAD/zwitterionic surfactant binary mixtures remains unclear.Herein,the self-assembly of hydroxyl derivatives of benzoic acid(BA)and cetyldimethyl betaine(BS-16)mixtures in water was systematically assessed,and various factors,such as the molecular structure,molar ratio of AAD and BS-16,and solution pH,were investigated.The structure-property relationship of AAD/BS-16 binary mixtures was established,which provided the molecular origin for the effect of AAD on micellar microstructures and the pH-induced morphological transitions.The ortho-substituted hydroxyl moiety in the BA molecule facilitated the formation of larger wormlike micelles,whereas the effect of the meta-substituted moiety was less significant.The para-substituted hydroxyl moiety in BA did not favor micellar growth.This moiety exhibited similar characteristics to the increasing hydroxyl moiety number in the AAD molecules or solution pH where the negative effects of steric hindrance and electrostatic interactions of molecules in micelles aredominant.

关键词： Zwitterionic surfactants Aromatic acid derivatives pH response Wormlike micelles Spherical micelles Viscosity

Asymmetric Two-Component Alkenyl Catellani Reaction for the Construction of C—N Axial Chirality

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第7期42卷 699-704页

作者： Chenggui Wu Ze-Shui Liu Yong Shang Chang Liu Shuang Deng Hong-Gang Cheng Hengjiang Cong Yinchun Jiao Qianghui Zhou Sauvage center for Molecular Sciences Engineering Research Center of Organosilicon Compounds&Materials(Ministry of Education)Hubei Key Lab on Organic and Polymeric OptoElectronic MaterialsCollege of Chemistry and Molecular SciencesThe Institute for Advanced Studiesand TaiKang Center for Life and Medical SciencesWuhan UniversityWuhanHubei 430072China Key Laboratory of Xin'an Medicine Ministry of EducationAnhui University of Chinese MedicineHefeiAnhui 230038China School of Chemistry and Chemical engineering Hunan University of Science and TechnologyXiangtanHunan 411201China

Herein,we report an asymmetric two-component alkenyl Catellani reaction for the construction of C—N axial chirality through a palladium/chiral norbornene cooperative catalysis and an axial-to-axial chirality transfer process.Various partially aromatic iodinated 2-pyridones,quinolones,coumarin and uracil substrates react with 2,6-disubstituted aryl bromides with a tethered amide group,to afford a wide variety of polycyclic C—N atropisomers(38 examples,up to 97%e.e.).The obtained C—N axial chirality originates from the preformed transient C—C axial chirality with high fidelity.The synthetic utility of this chemistry is demonstrated by facile prepa-ration of complex quinoline and pyridine based C—N atropisomers through a N-deprotection and aromatization sequence.In addi-tion,a remote axial-to-central diastereoinduction process dictated by C—N axial chirality is observed with excellent diastereocontrol.

关键词： Alkenyl Catellani reaction Asymmetric catalysis Atropisomerism Axial-to-axial chirality transfer Heterocycles

Stereodivergent synthesis ofα-fluoroα-azaarylγ-butyrolactones via cooperative copper and iridium catalysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fundamental research 2024年第1期4卷 77-85页

作者： Kui Tian Xin Chang Lu Xiao Xiu-Qin Dong Chun-Jiang Wang College of Chemistry and Molecular Sciences Engineering Research Center of Organosilicon Compounds&MaterialsMinistry of EducationWuhan UniversityWuhan 430072China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryShanghai 230021China Suzhou Institute of Wuhan University Suzhou 215123China

The development of stereodivergent synthetic methods to access all four stereoisomers of biologically importantα-fluoroγ-butyrolactones containing vicinal stereocenters is of great importance and poses a formidable challenge owing to ring strain and steric hindrance.Herein,a novel asymmetric[3+2]annulation ofα-fluoroα-azaaryl acetates with vinylethylene carbonate was successfully developed through Cu/Ir-catalyzed cascade allylic alkylation/lactonization,affording a variety of enantioenrichedα-fluoroγ-butyrolactones bearing vicinal stereogenic centers with high reaction efficiency and excellent levels of both stereoselectivity and regioselectivity(up to 98%yield,generally>20:1 dr and>99%ee).Notably,all four stereoisomers of these pharmaceutically valuable molecules could be accessed individually via simple permutations of two enantiomeric catalysts.In addition,other azaaryl acetates bearingα-methyl,α-chlorine orα-phenyl group were tolerated well in this transformation.Reaction mechanistic investigations were conducted to explore the process of this bimetallic catalysis based on the results of reaction intermediates,isotopic labelling experiments,and kinetic studies.

关键词： Asymmetric catalysis α-Fluoroγ-butyrolactones Synergistic catalysis Cascade reaction Stereodivergent synthesis

Ternary-phase layered cathodes toward ultra-stable and highrate sodium ion storage

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第4期43卷 1589-1598页

作者： Wen-Ji Yin Pei-Dan Su Qi Lu Xiao-Qiong Li Ji-Ming Peng Teng-Fei Zhou Ge-Meng Liang Yu-Liang Cao Hong-Qiang Wang Qing-Yu Li Si-Jiang Hu Guangxi Key Laboratory of Low Carbon Energy materials School of Chemistry and Pharmaceutical SciencesGuangxi Normal University Institutes of Physical Science and Information Technology Anhui University Department of Chemistry and Pharmaceutical Sciences Guilin Normal College College of Chemistry and Chemical engineering Huanggang Normal University School of Chemical engineering and Advanced materials The University of Adelaide engineering research center of organosilicon compounds and materials of ministry of education College of Chemistry and Molecular SciencesWuhan University

With the shortage of lithium resources,sodiumion batteries（SIBs） are considered one of the most promising candidates for lithium-ion batteries.P2-type and O3-type layered oxides are one of the few cathodes that can access high energy density.However,they usually exhibit structural change,capacity decay,and slow Na ion kinetic.Herein,we present layered ternary-phase cathodes with P2,P3 and O3 phases by a lattice doping strategy,which is demonstrated by X-ray diffraction（XRD） refinement.Combining the characteristics of P2,P3 and O3 phases,the layered composites show performance improvement during long-term battery cycling.In particular,Na0.7Li0.1Co0.3-Fe0.3Mn0.3O2（NLCFM） delivers a reversible capacity of120.1 mAh·g-1at 0.1C(1.0C=175 mA·g-1) with a superior capacity retention of 72.5% after 1000 cycles at10.0C.This work offers insights into the development of advanced cathode materials for SIBs.

关键词： Sodium-ion battery Cathode material Layered oxides Lattice doping Mixed phase

SnIP-type atomic-scale inorganic double-helix semiconductors: Synthesis, properties, and applications

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nano research 2024年第3期17卷 2111-2128页

作者： Mudussar Ali Bowen Zhang Muhammad Khurram Qingfeng Yan engineering research center of Advanced Rare Earth materials(ministry of education) Department of ChemistryTsinghua UniversityBeijing 100084China

Flexible inorganic double helical semiconductors similar to DNA have fueled the demand for efficient materials with innovative structures and excellent properties.The recent discovery of tin phosphide iodide(SnIP),the first carbon-free double helical semiconductor at an atomic level,has opened new avenues of research for semiconducting devices such as thermoelectric and sensor devices,solar cells,and photocatalysis.It has drawn significant academic attention due to its high structural flexibility,band gap in the visible spectrum range,and non-toxic elements.Herein,the recent progress in developing SnIP,including its prestigious structure,versatile and intriguing properties,and synthesis,is summarized.Other analogues of SnIP and SnIP-based hybrid materials and their applications in photocatalysis are also discussed.Finally,the review concludes with a critical summary and future aspects of this new inorganic semiconductor.

关键词： tin phosphide iodide(SnIP) inorganic semiconductor inorganic double helix SnIP-based hybrids photocatalysis flexible material

Progress in processing of porous titanium: a review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第5期43卷 1932-1955页

作者： Xiao-Li Yang Xian-Feng Du Zhi-Lin Xu Zhong-Shuai Liang Li-Long Xiong engineering research center of Energy Storage materials and Devices Ministry of Education School of Chemistry Xi'an Jiaotong University

As a novel structural and functional material,porous titanium and its alloys have been widely used in the aerospace, marine engineering and biomedical fields due to their high corrosion resistance, low density, good biocompatibility and excellent mechanical properties. Therefore, in this paper, a comprehensive review of powder metallurgy(PM)(including additive manufacturing(AM)processes) for fabricating porous titanium is firstly covered in terms of their working principles, capabilities, shortcomings and strengths. Simultaneously, the influencing factors of various methods on final pore structure of porous Ti are involved. Secondly, a summary of the chemical methods(CM) to obtain the porous Ti is also provided,such as dealloying method and reduction method. Finally,the tendency and direction of preparation technology as well as application of porous titanium were prospected.

关键词： Porous titanium Powder metallurgy Chemical method Pore structure Processing process

Improvement of impact properties of Al-Si-Mg alloy via solution treatment and joint modification with Sr and La

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第7期43卷 3301-3313页

作者： Xiong-Ling Zheng Shao-Xiang Li Jia-Le Ma Qing-Yan Xu Hai-Dong Zhao Zhi-Qiang Han Key Laboratory for Advanced materials Processing Technology Ministry of EducationSchool of Materials Science and EngineeringTsinghua University National engineering research center of Near-Net Shape Forming for Metallic materials South China University of Technology

An effort to obtain superior impact properties for Al-7Si-0.35 Mg alloy is presented,where modification with 0.02 wt% Sr and 0.1 wt% La as well as solution treatment was jointly employed.The samples were solution treated at 535℃ for 15 min to 12 h.The microstructure,fracture mechanism,and their correlation with the impact properties of the alloy were studied in detail mainly through optical microscopy（OM）,scanning electron microscopy（SEM） and oscillography impact test.The results show that the addition of Sr and La refined the eutectic Si particles significantly from～ 2.05 μm（modified with Sr alone） to～ 0.75 μm in as-cast microstructure,leading to a very homogeneous distribution of spheroidized Si particles in the alloy solution treated at 535℃ for 8 h.The alloy exhibits excellent impact toughness up to 75 J·cm-2,which is much higher than the maximum impact toughness of the alloys modified by Sr alone(～ 46 J·cm-2).The major reason for this remarkable increase in the impact property is the dramatic increase in crack initiation energy.The dispersoid-free zones（DFZs）near the eutectic regions mainly consist of the ductile Al-matrix,which exhibits excellent ductility.The ductile Al-matrix of the DFZs hinders the crack propagation,resulting in a significant increase in crack propagation energy.

关键词： Aluminum alloys Modification Solution treatment Microstructure Impact properties Fracture mechanism