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A combined experimental and computational study of NHC-catalyzed allylation of allenoate with MBH esters:new regiospecific and stereoselective access to 1,5-enyne

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Organic Chemistry Frontiers 2022年第1期9卷 51-57页

作者： Fang Sun Fangfang Lu Xue Song Wenchao Wu Kai Zhang Chenxia Yu Tuanjie Li Donghui Wei changsheng yao Jiangsu Key Lab of Green Synthetic Chemistry for Functional Materials School of Chemistry and Materials ScienceJiangsu Normal UniversityXuzhouJiangsu 221116P R China. The College of Chemistry and Molecular Engineering Zhengzhou University100 Science AvenueZhengzhouHenan 450001P R China

An NHC-catalyzed regiospecific allylation ofα-substituted allenoates with MBH carbonates derived from aryl aldehyde furnished highly functionalized 1,5-enynes bearing a quaternary carbon *** with DFT calculations,the reaction mechanism of this conversion was *** method has the advantages of high regioselectivity,good yields and mild reaction *** transformation not only provided a new access to 1,5-enyne,but also enriched the chemistry of allenoates and NHC catalysis.

关键词： conditions catalysis allyl

Enhancing Site Style Tree Construction Algorithm

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Wuhan University Journal of Natural Sciences 2009年第2期14卷 129-133页

作者： ZHU Fuxi GONG changsheng yao Haitao DONG Wenyong School of Computer Wuhan University Wuhan 430072Hubei China

The World Wide Web has become a global information service center with a vast amount of news, advertisements, product and service information, and disparate information from diversi- fied sources. However, only a small portion of information is truly relevant and useful to the users who are seeking information on specific topics. In this paper, common relations among nodes are taken into consideration when constructing site style tree, and a new node type is introduced. Experimental results show that the proposed algorithm has higher precision and recall.

关键词： site style tree Web mining noise clean

Asymmetric cascade syntheses of heterocycles catalyzed by NHC

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Asymmetric cascade syntheses of heterocycles catalyzed by NH...

中国化学会第十四届全国有机合成化学学术研讨会

作者： Tuanjie Li Chenxia Yu changsheng yao School of Chemistry and Materials Science Jiangsu Normal University

Over the past several decades,N-heterocyclic carbenes (NHCs) have evolved into a powerful kind catalysts for organic *** from the classical polarity of aldehyde (a-d)and enal (a-d),ring-opening polymerization and transesterification could also be promoted by ***,much effort has been devoted to the generation and reactivity of NHC-bounded intermediates such as homoenolate,vinyl enolate,α,β-unsaturated azolium and azolium enolate converted from functionalized aldehyde and ***,we would like to report our recent study on the NHC-catalyzed formation of these key intermediates from readily available starting materials includingα-bromoenal,α,β-unsaturated carboxylic acids and their derivatives and the subsequent asymmetric [3+2],[3+3]or [4+2] annulation to construct heterocyclic scaffolds with biological potential.

关键词： N-heterocyclic carbene cascade synthesis heterocycles

An NHC-catalyzed assembly of spirocyclic oxindole-cyclopentene

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An NHC-catalyzed assembly of spirocyclic oxindole-cyclopente...

中国化学会第十三届全国有机合成化学学术研讨会

作者： Jiang Ligen Que Yonglei Li Tuanjie Yu Chenxia yao changsheng School of Chemistry and Chemical Engineering Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional MaterialsJiangsu Normal University

The spirocyclic oxindole-cylopentene skeletons featured in a large number of nature products have potential biological ***,various approaches such as phosphine catalysis,and metal-mediated multistep transformations,have been performed to realize the successful assembly of ***,the lengthiness of synthetic route and complexity of the starting materials necessitate the developement of new telescoped protocol to construct this *** synthesis of diverse cyclopentenes utilizing different unsaturated aldehydes and α,β-unsaturated ketones catalyzed by N-Heterocyclic Carbene（NHC） has been reported by Nair and *** envisioned that the conversion of α-enal and NHC into NHC-bounded homoenolate and the following cyclization with the oxindole-derived α,β-unsaturated ketone may pave a new avenue to the spirocyclic oxindole-cylopentene.

关键词： N-Heterocyclic Carbene spirocyclic oxindole-cylopentene

NHC-Catalyzed Three-Component Domino Reaction of Bromoenals with Oxindoles: Diastereoselective Assembly of Spirooxindole 4H-Pran-2-Ones

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NHC-Catalyzed Three-Component Domino Reaction of Bromoenals ...

中国化学会第十四届全国有机合成化学学术研讨会

作者： Yong Hu Baomin Sun Chenxia Yu Tuanjie Li Shujiang Tu changsheng yao School of Chemistry and Materials Science Jiangsu Normal University

Spirooxindoles are frequently present as important cores in large amounts of natural products,pharmaceutically relevant synthetic compounds with highly biological activities. As a novel class of spirooxindoles, only a few investigations have been focused on the syntheses and bioactivities of spirooxindole 4H-pyran-2-ones. N-heterocyclic carbene(NHC)catalysis has been used as a powerful tool for a large number of untypical chemical transformations. Among these conversions,α,β-unsaturated acyl azoliums have emerged as fascinating1,3-biselectrophile synthons with unique and unprecedented chemistry that were pioneered by Zeitler in 2006. The well-explored reactions involved NHC-mediated formal[3+3]annulations ofα,β-unsaturated acyl azoliums with various 1,3-bisnucleophiles to afford functionalized dihydropyranones and dihydropyridinones. However,to the best of our knowledge,the three-component domino reaction of bromoenals are rarely *** continuation of our studies on the exploration of NHC-catalyzed annulations for the synthesis of diverse heterocyclic systems, we shall herein report that oxindoles serve as 1,1-bisnucleophiles to undergo three-component domino reaction,which provides a new access to spirooxindole 4H-pyran-2-ones.

关键词： spirooxindoles N-heterocyclic carbenes α,β-unsaturated acyl azloliums

N-Heterocyclic Carbene-Catalyzed[4+2]Cyclization of α-bromo-enal with 3-alkylenyloxindoles:an efficient synthesis of spirocyclic oxindoles

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N-Heterocyclic Carbene-Catalyzed[4+2]Cyclization of α-bromo...

中国化学会全国第十一届有机合成化学学术研讨会

作者： Yuanwei Xie Zhaoxin Xiao Tuanjie Li Rui Liu Chenxia Yu changsheng yao School of Chemistry and Chemical Engineering Jiangsu Normal University

N-heterocyclic carbene(NHC) catalyzed reactions have emerged as an particularly fruitful area of research in organic chemistry. Due to the unique "Umpolung" in organic synthesis,umpoluping the aldehydes to acyl nucleophiles has become an important way to synthesis of heterocyclic compounds in current research. Spirooxindole cores are interesting and important structures found in many bioactive natural products,and the functionalized six-membered spirooxindole core structure is featured in many natural products as well as medicinally relevant compounds. Herein we shall report our preliminary results of an NHC-catalyzed reaction of 2-bromo-2-enal bearing γ-H with 3-alkylenyloxindoles,which may give the desired spirocarbocyclic oxindoles with potential bioactivity.

关键词： NHC spirocyclic oxindole α-bromo-enal 3-alkylenyloxindole

An NHC-catalyzed Oxidative γ-Aminoalkylation of Saturated Carboxylic Acids through in situ Activation Strategy:A New Access to δ-Lactam

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An NHC-catalyzed Oxidative γ-Aminoalkylation of Saturated C...

中国化学会第九届全国有机化学学术会议

作者： Yonglei Que Yuanwei Xie Tuanjie Li Chenxia Yu Shujiang Tu changsheng yao School of Chemistry and Chemical Engineering Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional MaterialsJiangsu Normal University

Carboxylic acids y are less liable to enolize than ketone and activated esters,which may avoid the occurrence of the side reaction including aldol condensation,Michael addition and Claisen *** noticeable advantages make the carboxylic acids ideal starting materials for organic synthesis and considerable attention has been focused on their organocatalytic transformations.

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氮杂环卡宾(NHC)催化下多取代环戊烯的串联合成

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有机化学 2019年第5期39卷 1404-1410页

作者：李莎杨雯涵罗鲜姚昌盛江苏省功能材料绿色合成重点实验室江苏师范大学化学与材料科学学院

在氮杂环卡宾(N-heterocyclic carbene,NHC)催化下,α,β-不饱和羧酸经过原位活化后与2-(2-氧代-2-芳乙基)丙二腈发生Michael加成、羟醛缩合、脱羧等反应,一锅法合成了多取代环戊烯类化合物.该方法具有底物范围广、原料易得、反应条件... 详细信息

在氮杂环卡宾(N-heterocyclic carbene,NHC)催化下,α,β-不饱和羧酸经过原位活化后与2-(2-氧代-2-芳乙基)丙二腈发生Michael加成、羟醛缩合、脱羧等反应,一锅法合成了多取代环戊烯类化合物.该方法具有底物范围广、原料易得、反应条件温和、产率高、操作简便等优点,为多官能化环戊烯类化合物的高效合成提供了新思路.

关键词：氮杂环卡宾(NHC) α,β-不饱和羧酸 2-(2-氧代芳乙基)丙二腈多取代环戊烯串联反应

A Stereoselective Assembly of Dihydropyranone through NHC/LiCl-catalyzed in situ Activation of α,β-Unsaturated Carboxylic

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A Stereoselective Assembly of Dihydropyranone through NHC/Li...

中国化学会第九届全国有机化学学术会议

作者： Yonglei Que Chenxia Yu Tuanjie Li Xiang-Shan Wang Shide Shen changsheng yao Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials School of Chemistry and Chemical EngineeringJiangsu Normal University Xuzhou Institute of Architectural Technology

＜正＞The carboxylic acids are readily available,more stable compared with enal and the functionalized aldehydes includingα-aryloxy acetal aldehydes and halogenated aldehydes employed previously in NHC-catalyzed ***,they are less liable to generate enolate than ketones and activated esters,which may avoid some side reactions such as Aldol reaction and Michael reaction.

关键词：