检索结果-南通市图书馆

A Highly cis-Selective Cascade aza-Michael/Aldol Annulation of Tetrahydroisoquinolines with Ethyl(2-Formylphenyl) Vinylphosphonates to Construct cis-3-Aminomethyl-4-HydroxyPhosphadihydrocoumarins

A Highly cis-Selective Cascade aza-Michael/Aldol Annulation ...

引用

中国化学会·第十五届全国有机合成化学学术研讨会

作者： Qinghe Wang Huang Tiao 吴明书 College of chemistry & Chemical Engineering Hainan Normal University 海南师范大学

Coumarins are common structural motifs that are found in a variety of natural products and *** them, 3,4-dihydrocoumarins have shown many biological activities such as anti-cancer, anti-inflammatory actions, anti-microbial properties, anti-tumor, anti-oxidation agents, etc. The organophosphorus compounds often exhibited biochemical activity similar to that of naturally occurring carboxylic acids and their derivatives. Therefore, as phosphorous analogues of dihydrocoumarin, the phosphadihydrocoumarins would have pharmacological activities similar to those described for *** a consequence, we were attracted in developing efficient methods for the construction of a number of phosphadihydrocoumarins, we devised a new synthetic intermediate based on vinylphosphonate and hope to use it as a new synthon for the construction of phosphadihydrocoumarins with the purpose of making focused chemical libraries useful for synthetic methodology research and drug discovery. Here in, we describe a highly cis-selective cascade aza-Michael/Aldol-like annulation of ethyl(2-formylphenyl)vinylphosphonates with tetrahydroisoquinolines for the construction cis-3-aminomethyl-4-hydroxyphosphadihydrocoumarins which could be readily converted into β-hydroxyl-β’-amino alkylphosphonates under simple *** is also worth noting that the direct accessing of 1,3-amino alcohols, which is attracting great attention in recently, was achieved in this process.

关键词： phosphadihydrocoumarin organophosphorus compound dihydrocoumarin

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Copper-catalyzed Decarboxylic Multicomponent Reactions: Facile Access to Pyrimido Imidazoles and Imidazo Thiazoles

Copper-catalyzed Decarboxylic Multicomponent Reactions: Faci...

引用

中国化学会·第十五届全国有机合成化学学术研讨会

作者： Huan Luo 张琦 School of chemistry and Chemical Engineering Shaanxi Normal University 陕西师范大学

Pyrimido imidazoles and imidazo thiazoles are key structural scaffolds in a broad variety of natural products, drug molecules, and functional materials .Although a number of elegant methods have been established for the synthesis of these two kinds of compounds, new facile and efficient synthetic approaches are still in great ***, we have described a straightforward access to diverse synthesis of 2,3-, 2,4-disubstituted pyrimido imidazoles, 2,4,10-trisubstituted 2,10-dihydropyrimido imidazoles and 2,3-disubstituted imidazo thiazoles through decarboxylic multicomponent reactions(MCRs) of heteroclyclic azoles, aldehydes with easy-storage and-handling alkynecarboxylic *** the presence of a catalytic amount of CuI and KCO, the pyrimido imidazole or imidazo thiazole scaffold could be rapidly constructed involving a 6-endo-dig or 5-exo-dig cyclization, *** preliminary mechanistic study suggested that the one-pot formation of 2,3-disubstituted pyrimido imidazoles undergoes a novel cascade process involving a decarboxylation, A coupling, 6-endo-dig cyclization, nucleophilic addition and ***, some new synthesized compounds were proved to be suitable candidates as selective fluorescence sensors for metal ion Fe.

关键词： pyrimido imidazole imidazo thiazole MCRs diverse synthesis alkynecarboxylic acids

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Palladium Catalyzed Enantioselective Cycloadditions of Imines and Vinyl Cyclopropanes

Palladium Catalyzed Enantioselective Cycloadditions of Imine...

引用

中国化学会·第十五届全国有机合成化学学术研讨会

作者： Long He Wen-Dao Chu Ze-Shui Liu Xiao-Bin Huang 刘全忠 College of chemistry and Chemical Engineering China West Normal University 西华师范大学

The optically enriched pyrrolidine and cyclopentane derivatives are privileged structure and constitute the structural core in numerous natural products and biologically active molecules .Although fruitful methodologies have been developed for the construction of pyrrolidine and cyclopentane framework, direct enantioselective [3+2] cycloaddition of vinyl cyclopropane derivatives with imines or electron deficient olefins are still highly *** we would like to disclose our preliminary results toward this *** catalysed enantioselective cycloadditions of imines or conjugated unsaturated imines and vinyl cyclopropanes in the presence of chiral phosphoramidtes are achieved with in high yields and with high stereoselectivities.

关键词： [3+2] cycloaddition pyrrolidine cyclopentane vinyl cyclopropanes imine

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Assessment of Present and Future Radioactive Contamination at Global Scale

引用

Journal of chemistry and Chemical Engineering 2012年第11期6卷 1010-1015页

作者： Juan Manuel Navarrete Miguel Angel ZUNiga Guillermo Espinosa Jose Ignacio Golzarri Faculty of chemistry National University of Mexico Mexico City 04510 Mexico Institute of Physics National University of Mexico Mexico City 04510 Mexico

As a result of more than two thousand nuclear tests performed since 1945, two war actions and few accidents in nuclear reactor, it does already exist a radioactive contamination at global scale. This contamination has been accumulated mainly in marine sediments, because sea is about 80% of planet surface, and solid fission products released by nuclear explosions are transported by wind first and then by rain to liquid and solid portions on earth, while gaseous fission products are diffused in the atmosphere. In this way, heavy, high yielding fission products, such as 137Cs, get marine sediments, where they are found mixed with heavy radioactive natural elements such as U, Th and their also radioactive decay products. But since alkaline are so abundant on earth, it is also found natural radioactive isotope 4~K, 0.0118% of isotopes forming K element, with half life 1.28 ~ l09, in the time range of planet age and elements origin. So, one easy way to assess both the importance and evaluation of radioactive contamination at global scale should be to establish a RCF （radioactive contamination factor） as a percentage of 137Cs contaminant radioactivity in marine sediments, compared to 4~K natural radioactivity present from the very beginning of earth, both expressed as Bq per gram of sediment. In the frame of these rather general considerations, a research project has started in Mexico whose varied purposes are： to characterize sea regions in both vast littorals in the country, by its natural 4~K radioactivity present in sea salts, as well as to determine if 137Cs traces produced by recent radioactive contamination have reached their coasts. Also, to assess the 137Cs traces already present in marine sediments as a result of more than two thousand nuclear test explosions performed till now, rather than contamination produced by four main accidents in nuclear reactors during the last 60 years. It is proposed a radioactive contamination factor obtained from samples taken up in

关键词： Contaminant natural radioactivity relation coefficient.

来源：

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

Cytotoxic and pro-apoptotic activities of sesquiterpene lactones from Inula britannica

Cytotoxic and pro-apoptotic activities of sesquiterpene lact...

引用

中国化学会第十届全国天然有机化学学术会议

作者： Xin Guo Jiang-Jiang Tang Jin-Ming Gao Shaanxi Engineering Center of Bioresource chemistry ＆ Sustainable Utilization College of Science Northwest A＆F University

＜正＞Plant-derived drugs are important in cancer therapy due to their low toxicity and high *** bioactive natural products found in medicinal herbs are considered to be potential anticancer *** recent years,the anticancer properties of natural compounds containing anα-methylene-γ-lactone moiety attracted a lot of attention due to binding thiols of proteins or

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Synthesis of novel substituted 2-aryl-3-(3'-oxobutenyl)benzoxazole

Synthesis of novel substituted 2-aryl-3-(3'-oxobutenyl)benzo...

引用

中国化学会·第十五届全国有机合成化学学术研讨会

作者： Kaixuan Wang 王兰芝 The College of chemistry and Material Science Hebei Normal University 河北师范大学

N-Heterocyclic compounds are the main building blocks in synthetic organic ***,benzoxazole derivatives have attracted considerable attention because of their wide variety of applications in agrochemicals, natural products, functional materials and pharmaceutically active *** of the benzoxazole derivatives, which are already booming in the market, to quote a few, pseudopteroxazole(antimicrobial agent), UK-1(anticancer agent), flunoxaprofen(NSAID), tafamidis(hereditary amyloidosis).Owing to such significance,the synthesis of benzoxazole and its derivatives has been an attractive goal for organic and medicinal ***, we designed and synthesized a series of unreported novel substituted 2-aryl-3-(3’-oxobutenyl)benzoxazole in three *** intermediates(5a-5i) were obtained via the condensation reaction of 2-aminophenol(1) with para-substituted benzaldehyde(2) and 3-butyn-2-one(4) under CHCHOH at ambient *** of intermediates 5 in the presence of a catalytic amount of CHCOOH in CHCl at 25℃ resulted in the formation of the 2-aryl-3-(3’-oxobutenyl)benzoxazole(6a～6i) in 90% yield(Scheme 1).The target compounds were determined by HNMR, CNMR, MS, IR and elemental analysis.

关键词： benzoxazole synthesis 2-aminophenol

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Preparation 2(5H)-Furanone Derivatives Using Oxygen-group Reagents and Their Bioactivity Investigation

Preparation 2(5H)-Furanone Derivatives Using Oxygen-group Re...

引用

中国化学会·第十六届全国有机合成化学学术研讨会

作者：杨凯 Han-Qing Wu Bo-Wen Wang Shi-He Luo Jun-Ru Zhang Jie-Luan Cheng Zhao-Yang Wang 华南师范大学 School of chemistry and Environment South China Normal University

2(5H)-Furanone belongs to the class of α,β-unsaturated lactones,and the compound containing this structural unit is not only widely present in natural products,but also has potential medicinal value. Meanwhile,the research on organic synthesis based on oxygen-group organic reagents has been very popular in recent years. Especially,the research on the construction of C-O,C-S and C-Se bonds through various reaction conditions has become a *** our work,we used 3,4-dihalo-2(5H)-furanones as the reaction synthons to study their reaction(such as etherification,sulfur/selenocyanation) with different oxygen-group organic *** in the above experiments,the ring opening reaction of DABCO was unexpectedly ***,the bioactivity of the products synthesized from 2(5H)-furanone synthons has also been investigated. The more works are in progress.

关键词： oxygen-group reagents 3,4-dihalo-2(5H)-furanones metal-free DABCO three-component reaction

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

An Efficient [3+2] Cycloaddition of para-Quinone Methides with Nitrile Imines to Construct Spiro-pyrazoline-cyclohexadienones

An Efficient [3+2] Cycloaddition of para-Quinone Methides wi...

引用

中国化学会·第十六届全国有机合成化学学术研讨会

作者： Yanan Zhao 苏瀛鹏 Danfeng Huang Ke-Hu Wang Yulai Hu College of chemistry and Chemical Engineering Northwest Normal University 西北师范大学

Spirocyclohexadienones and pyrazolines are prevalent core structures in bioactive molecules and natural products. On the other hand,spiro compounds have continued to gain attentions in recent years because of their diversified biological activities and pharmacological properties.3 Thus,combining the pyrazolines and cyclohexadienone structural motifs simultaneously into one molecule as spiro-pyrazoline-cyclohexadienones may be significant for drug candidate discovery. Herein,we developed an eficient [3+2] cycloaddition of para-quinone methides and nitrile imines to construct spiro-pyrazoline-cyclohexadienones with high re gio *** p-QMs and nitrile imines bearing electron-donating or electron-withdrawing groups on the phenyl rings were well-tolerated,providing the spiropyyazolines in good to excellent *** straightforward protocol for efficient construction of the privileged spiropyrazolines may be further applied in the pharmaceutical industry and make particularly attractive in organic synthesis.

关键词： Spirocyclohexadienones pyrazolines [3+2] cycloaddition para-quinone methides nitrile imines

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Bio-inspired Total Syntheses of Cephalotaxus Diterpenoids

Bio-inspired Total Syntheses of Cephalotaxus Diterpenoids

引用

中国化学会·第十五届全国有机合成化学学术研讨会

作者： Lun Xu Chao Wang Ziwei Gao 赵玉明 School of chemistry and Chemical Engineering Shaanxi Normal University 陕西师范大学

＜正＞Plants of the Cephalotaxaceae family produce an extensive array of structurally diverse natural products with a variety of biological properties, particularly potent antitumor *** these secondary metabolites, cephalotaxus diterpenoids represent a relatively rare and structurally fascinating class of natural *** to date, over 25 diterpenes with rigid polycyclic frameworks have been isolated many of which also possess significant biological activities.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Synthesis of novel substituted 2-phenyl-4-esteryl-1,5-benzothiazepines

Synthesis of novel substituted 2-phenyl-4-esteryl-1,5-benzot...

引用

中国化学会·第十五届全国有机合成化学学术研讨会

作者： Lin He Minyue Zhang 王兰芝 The College of chemistry and Material Science Hebei Normal University 河北师范大学

1,5-benzothiazepines are constitute valuable structural units for all sorts of important natural products, chemical products, pharmaceuticals, conjugated polymers and other *** 1,5-benzothiazepines hold many medicinal applications like sedative, psychoactive drug, hypnotic agents, anticonvulsant, anti-depressive and *** bring the –COOR,-Ph-COR active groups on the seven-membered heterocycle, a new 1,5-benzothiazepines can be obtained with higher biological *** view of our continuous interest in the synthesis of new benzothiazepine derivatives, we wished to examine the possibility of synthesis of 1,5-benzothiazepines incorporating free ester and phenyl moiety on the seven-membered ring *** we have designed and synthesized a series of novel substituted 2-phenyl-4-esteryl-1,5-benzothiazepines through three steps *** accordance with Scheme 1, 2-oxo-4-phenyl-3-butenoic acids(1) are obtained via aldol condensation reaction of ethyl pyruvate with substituted *** then,2-oxo-4-phenyl-3-butenoic acid ethyl esters(2) were synthesized via esterification *** addition of o-aminothiophenol to 4-(substituted-phenyl)-2-oxo-3-butenoate yielded and the intramolecular cyclisation, followed by dehydration in PMA-SiO/ethanol provided 2-(substituted-phenyl)-4-ester-1,5-benzothiazepines, which were purified by crystallization from dry *** ending of the reaction(TLC), compounds(3) were obtained in a pure state in 82–95% *** 2-(substituted-phenyl)-4-ester-1,5-benzothiazepines(Scheme 1) were synthesized successfully by simple *** compounds were characterized by H NMR, C NMR, MS, and *** distinct advantages of our procedure are simple methodology, fast reaction rate and the PMA-SiO catalyst was used directly four times without a considerable loss of its catalytic activity.

关键词： Synthesis 1,5-benzothiazepines esteryl compounds

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：