检索结果-南通市图书馆

Chinese Journal of Chemistry 2024年第10期42卷 1128-1132页

作者： Chao Li Lei Chen Hongye Wang Zixi Yan Bin Lyu Weiping Lyu Changwei Jiang Dehua Lu Jiaxing Li Ning Jiao Song Song State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical SciencesPeking UniversityXue Yuan Rd.38Beijing 100191China

A mild and practical method for synthesizing fluorinated quinoline derivatives,which have a wide range of applications in pharmaceuticals,materials,and organic synthesis,was described through C—F bond insertion into indoles using CHBr_(2)F.The simple conditions,readily availability of CHBr_(2)F,as well as the versatility of the transformations make this strategy very powerful in synthesizing 3-fluoroquinoline and 3-fluoroquinolone.The mechanistic studies reveal that bromofluorocarbene generated in-situ under basic condition was the key intermediate.

关键词： Skeleton edit Fluorocarbene ring expansion Quinoline Quinolone

MeOTf-catalyzed formal[4+2]annulations of styrene oxides with alkynes leading to polysubstituted naphthalenes through sequential electrophilic cyclization/ring expansion

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 Chemical Letters 2022年第6期33卷 3021-3025页

作者： Song Zou Zeyu Zhang Chao Chen Chanjuan Xi MOE Key Laboratory of Bioorganic Phosphorus Chemistry&Chemical Biology Department of ChemistryTsinghua UniversityBeijing 100084China State Key Laboratory of Elemento-Organic Chemistry Nankai UniversityTianjin 300071China

Me OTf-catalyzed formal[4+2]annulation of styrene oxides with alkynes to afford polysubstituted naphthalenes has been realized,which undergoes sequential electrophilic cyclization/ring expansion.A range of substrates were tolerated in the formation of naphthalene derivatives with high regioselectivity in satisfactory yields.The reaction could also be carried out on gram scale.

关键词： Methyltriflate Catalytic reaction Annulation ring expansion Polysubstituted naphthalenes

Electrochemical ring expansion to Synthesize Medium-Sized Lactams Through C–C Bond Cleavage

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

CCS Chemistry 2021年第8期3卷 2236-2247页

作者： Kun Liu Chunlan Song Xu Jiang Xin Dong Yuqi Deng Wenxu Song Yanpei Yang Aiwen Lei College of Chemistry and Molecular Sciences Institute for Advanced Studies(IAS)Wuhan UniversityWuhan 430072 State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryShanghai 230021

Medium-sized nitrogen heterocycles are prevalent motifs in many kinds of bioactive molecules and natural products.Owing to the unfavorable enthalpic and entropic barriers during the transition states,access to medium-sized rings is challenging.Herein,a general and practical electrochemical ringexpansion protocol has been developed from commercially available benzocyclic ketones and amides.In this regard,a series of highly functionalized eightto eleven-membered lactams could be successfully accessed in high yields and efficiencies.

关键词： electrochemistry medium-sized lactam ring expansion C–C bond cleavage nitrogen radical

[3+2]Cycloaddition of Vinyl Cyclopropane and Hydroxylamines via Isocynate Intermediate toγ-Lactams

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 2023年第16期41卷 1937-1942页

作者： Xiaobing Huang Jingxun Yu Xinjun Luan Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education College of Chemitry&Materials ScienceNorthwest UniversityXi'anShaanxi 710127China

Comprehensive Summary A general and efficient strategy for the synthesis ofγ-lactams has been reported.The hydroxylamines form Lossen rearrangement products of electron-deficient group migration with base and then undergo[3+2]cycloaddition reaction with vinyl cyclopropane,which could be performed with broad substrate scope,excellent functional group tolerance and high efficiency to produce the desired products.It also allowed further modification to other derivatives of theseγ-lactams.

关键词： γ-Lactams Hydroxylamines VinyI cyclopropane Pd-catalyzed [3+2]cycloaddition Amination Insertion ring expansion

Palladium-Catalyzed Skeletal Reorganization of Cyclobutanones Invoving Successive C—C Bond/C—H Bond Cleavage

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国化学:英文版 2023年第14期41卷 1679-1683页

作者： Ruirui Li Xiaonan Shi Dongbing Zhao State Key Laboratory and Institute of Elemento-Organic Chemistry College of ChemistryNankai UniversityTianjin300071 China

The utilization of cyclobutanones as the synthon in transition metal catalysis has been made great success.Because C(carbonyl)−C bond of cyclobutanones can be cleaved through strain release.Despite those advancements,the main catalysts in literature are Rh catalysts or Ni catalysts and the reaction with C—H bond is still underdeveloped.Herein,we realized the first palladium-catalyzed skeletal reorganization of cyclobutanones involving successive cleavage of C(carbonyl)−C bonds and C—H bond cleavage,which constitutes an rapid access to diverse indanones.In contrast to the previous Rh-catalytic system,the Pd-catalytic system herein involves different mechanism and features several advantages:1)no need of directing group to facilitate the C(carbonyl)−C bond cleavage;2)much milder reaction condition and 3)simplified work-up.

关键词： Cyclobutanones C-C activation C-H activation Palladium catalysis ring expansion

Reversing Site-Selectivity in Formal Cross-Dimerization of Benzocyclobutenones and Silacyclobutanes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CCS Chemistry 2023年第8期5卷 1753-1762页

作者： Jinyu Zhang Deng Pan Hao-Xiang Zhang Nuo Yan Xiao-Song Xue Dongbing Zhao State Key Laboratory and Institute of Elemento-Organic Chemistry College of ChemistryNankai UniversityTianjin 300071 Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai 200032 School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024

Formal cross-dimerization of two different strained rings represents an innovative strategy toward specific ring systems that are otherwise inaccessible.Yet,formidable challenges remain in controlling the reactivity and site-selectivity.Herein,we realized the reversal of site-selectivity in formal crossdimerization of benzocyclobutenones(BCBs)and silacyclobutanes(SCBs)by development of a nickel/magnesium synergistic catalytic system,in which the C(sp3)−C(carbonyl)bond of BCBs was exclusively cleaved,providing previously inaccessible eight-membered benzosilacycles.The catalytic cycle,the origin of this unconventional site-selectivity,and the role of MgCl2 have explicitly been elucidated by density functional theory calculations.Combined experimental and computational studies have clearly illustrated that the C1-C8 cleavage selectivity of BCBs in our reaction are mainly attributed to both the steric hindrance by introduction of substituents at the C3-and the proper choice of the Ni/Mg synergistic catalytic system.

关键词： ring expansion silacycles C-Si bond cleavage C-C bond cleavage nickel catalysis

A convenient synthesis of 2-aryl substituted benzo[f][1,2,4]triazolo[1,5-a]azepine derivatives

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 Chemical Letters 2007年第7期18卷 785-787页

作者： Qing Qing Meng He Xiang Bai Feng Li Quan Rui Wang Feng Gang Tao Department of Chemistry Fudan University Shanghai 200433 China

A convenient synthetic pathway to 2-aryl-5,6-dihydro-4H-benzo[f][1,2,4]triazolo[1,5-a]azepine derivatives 7 was developed.The synthesis was based on the cycloaddition of the 1,2,3,4-tetrahydronaphthalene α-acetoxy az... 详细信息

关键词： Benzotriazoloazepine Nitriles 1,3-Dipolar cycloaddition ring expansion

Metallacycle expansion and Annulation:Access to Tetrazolo-Fused Osmacycles by Reaction of Cyclic Osmium Carbyne with Sodium Azide

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2021年第12期39卷 3435-3442页

作者： Hongjian Wang Yu-Mei Lin Siyuan Chen Yonghong Ruan Haiping Xia State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Shenzhen Grubbs Institute Department of ChemistrySouthern University of Science and TechnologyShenzhenGuangdong 518055China

The reaction of a cyclic osmacarbyne complex with sodium azide led to the formation of a ring expansion-annulation product,a unique tetrazole annulated polycyclic metallacycle.The reaction proceeds by insertion of a nitrogen atom into the metal carbon triple bond and the second azide participating in the[2+3]cycloaddition.The successful isolation and characterization of metalla-azirine complex and metallapyridinium derivative strongly validated the mechanism for the formation of the title complex.The work demonstrates a new strategy to enrich the varieties of aza-metallacyclic species.

关键词： Metallacycles Osmiurncarbyne ring expansion Annulation Aza-heterocycle

Cycloadditions of 1-iminylphosphirane complexes with allenes

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 Chemical Letters 2021年第1期32卷 449-452页

作者： Juan Li Mingyue Cui Rongqiang Tian Zheng Duan François Mathey College of Chemistry Green Catalysis CenterInternational Phosphorus LaboratoryInternational Joint Research Laboratory for Functional Organophosphorus Materials of Henan ProvinceZhengzhou UniversityZhengzhou 450001China

A cascade carbonylative ring expansion and [2+2]/[4+2] cycloaddition of strained 1-iminylphosphirane complexes with aryl allenes were reported.The carbonylative ring expansion of 1-iminylphosphirane complexes provides an azaphosphacyclohexone complex intermediate with a C=P double bond.The following [2+2] or dearomatic [4+2] cycloaddition of this intermediate with allenes is modulated by the aryl substituents on the imino carbon.The regioselective [2+2] cycloaddition with 1,1-diarylallene provides an entry to bicyclo[4.2.0]octan-4-one skeletons featuring a four-membered phosphacyclobutane moiety.While dearomatic [4+2] cycloaddition was preferred with less aromatic naphthalene and yielded octahydrochrysene skeleton containing heteroatoms.

关键词： Phosphirane Allene ring expansion Cycloaddition Carbonylative Heterocycle