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Prof. Dr. J. Stephen Clark Filippo Romiti Kirsten F. Hogg Dr. Malai Haniti S. A. Hamid Sven C. Richter Dr. Alistair Boyer Joanna C. Redman Dr. Louis J. Farrugia 《Angewandte Chemie (International ed. in English)》2015,54(19):5744-5747
Chloroacetic acid promotes an efficient and diastereoselective intramolecular cascade reaction of electron‐deficient ynenones to deliver products featuring a 2,3,5‐trisubstituted furan bearing a fused cyclopropyl substituent at the 5‐position. Synthetically relevant polycyclic building blocks featuring rings of various sizes and heteroatoms have been synthesized in high yield using this mild acid‐catalyzed reaction. 相似文献
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Dr. Bo Peng Dr. Xueliang Huang Dr. Lan‐Gui Xie Prof. Dr. Nuno Maulide 《Angewandte Chemie (International ed. in English)》2014,53(33):8718-8721
A Brønsted acid catalyzed redox arylation of ynamides that employs aryl sulfoxides as the arylating agents is reported. This metal‐free transformation proceeds at room temperature and efficiently affords α‐arylated oxazolidinones in a redox‐neutral, atom‐economic fashion. 相似文献
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José Barluenga Prof. Dr. Abraham Mendoza Félix Rodríguez Dr. Francisco J. Fañanás Dr. 《Angewandte Chemie (International ed. in English)》2009,48(9):1644-1647
Functionalized spiroacetals have been easily prepared in a one‐pot three‐component coupling process that involves the reaction of pentynol derivatives, salicylaldehydes, and amines in the presence of catalytic amounts of a palladium(II) complex (see scheme). Alternatively, oxygen‐substituted spiroacetals can be obtained by using orthoesters as the third component.
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Self‐Relay Gold(I)‐Catalyzed Pictet–Spengler/Cyclization Cascade Reaction for the Rapid Elaboration of Pentacyclic Indole Derivatives 下载免费PDF全文
Valérian Gobé Dr. Pascal Retailleau Dr. Xavier Guinchard 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(49):17587-17590
Gold‐catalyzed cascade reactions allow the rapid elaboration of pentacyclic indolo[2,3‐a]quinolizidines from N‐allyl tryptamines and ortho‐alkynylarylaldehydes. The tandem process combines a gold‐catalyzed Pictet‐Spengler reaction and a cyclization occurring concomitantly with an allyl transfer from the nitrogen atom to the stilbene function. Various substituted allyls were successfully transferred, furnishing the products in yields typically ranging from 60–98 % in high diastereoselectivity. Tryptamines bearing a butenol chain undergo an additional cyclization to chiral hemiaminals in high diastereoselectivities. 相似文献
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Synthesis of Pyridazinones through the Copper(I)‐Catalyzed Multicomponent Reaction of Aldehydes,Hydrazines, and Alkynylesters 下载免费PDF全文
Anderson C. Mantovani Tales A. C. Goulart Prof. Dr. Davi F. Back Prof. Dr. Gilson Zeni 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(39):12663-12668
The copper‐catalyzed multicomponent cyclization reaction, which combined aldehydes, hydrazines, and alkynylesters, was applied in the synthesis of pyridazinones. The reaction was regioselective and gave only six‐membered pyridazinones in the complete absence of five‐membered pyrazoles or a regioisomeric mixture. During this investigation, the use of 2‐halobenzaldehyde as the starting material, under identical reaction conditions, gave 6‐(2‐ethoxyphenyl)pyridazinones after sequential Michael addition/1,2‐addition/Ullmann cross‐coupling reactions. 相似文献
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Palladium‐Catalyzed Three‐Component Cascade Reaction: Facial Access to Densely Functionalized Indolizines 下载免费PDF全文
Ren‐Rong Liu Chuan‐Jun Lu Ming‐Di Zhang Jian‐Rong Gao Prof. Dr. Yi‐Xia Jia 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(19):7057-7060
A palladium‐catalyzed three‐component cascade reaction of 2‐(2‐enynyl)pyridines with nucleophiles and allyl halides has been developed, enabling the synthesis of densely functionalized indolizines in moderate to good yields. The newly developed methodology offers several practical advantages, including operational simplicity, ready availability of starting materials, and mild reaction conditions. 相似文献
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Trio Catalysis Merging Enamine,Brønsted Acid,and Metal Lewis Acid Catalysis: Asymmetric Three‐Component Aza‐Diels–Alder Reaction of Substituted Cinnamaldehydes,Cyclic Ketones,and Arylamines 下载免费PDF全文
Dr. Yongming Deng Siddhartha Kumar Prof. Kraig Wheeler Prof. Hong Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(21):7874-7880
A trio catalyst system, composed of arylamine, BINOL‐derived phosphoric acid, and Y(OTf)3, enables the combination of enamine catalysis with both hard metal Lewis acid catalysis and Brønsted acid catalysis for the first time. Using this catalyst system, a three‐component aza‐Diels–Alder reaction of substituted cinnamaldehyde, cyclic ketone, and arylamine is carried out with high chemo‐ and enantioselectivity, affording a series of optically active 1,4‐dihydropyridine (DHP) derivatives are obtained in 91–99 % ee and 59–84 % yield. DHPs bearing a chiral quaternary carbon center are also obtained with good enantioselectivity and moderate yield (three examples). Preliminary mechanistic investigations have also been conducted. 相似文献
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Dr. Rosana Álvarez Claudio Martínez Youssef Madich J. Gabriel Denis Dr. José M. Aurrecoechea Prof. Dr. Ángel R. de Lera 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(42):12746-12753
Structurally diverse C3‐alkenylbenzofurans, C3‐alkenylindoles, and C4‐alkenylisoquinolones are efficiently prepared by using consecutive Sonogashira and cascade Pd‐catalyzed heterocyclization/oxidative Heck couplings from readily available ortho‐iodosubstituted phenol, aniline, and benzamide substrates, alkynes, and functionalized olefins. The cyclization of O‐ and N‐heteronucleophiles follows regioselective 5‐endo‐dig‐ or 6‐endo‐dig‐cyclization modes, whereas the subsequent Heck‐type coupling with both mono‐ and disubstituted olefins takes place stereoselectively with exclusive formation of the E isomers in most cases. 相似文献
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Avinash H. Bansode Aslam C. Shaikh Dr. Rahul D. Kavthe Shridhar Thorat Dr. Rajesh G. Gonnade Dr. Nitin T. Patil 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(6):2319-2323
The synthesis of small organic molecules as probes for discovering new therapeutic agents has been an important aspect of chemical biology. One of the best ways to access collections of small molecules is to use various techniques in diversity‐oriented synthesis (DOS). Recently, a new form of DOS, namely “relay catalytic branching cascades” (RCBCs), has been introduced, wherein a common type of starting material reacts with several scaffold‐building agents (SBAs) to obtain structurally diverse molecular scaffolds under the influence of catalysts. Herein, the RCBC reaction of a common type of substrate with SBAs is reported to give two different types of molecular scaffolds and their formation is essentially dependent on the type of catalyst used. 相似文献
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Estela Álvarez Dr. Olalla Nieto Faza Dr. Carlos Silva López Dr. Manuel A. Fernández‐Rodríguez Prof. Dr. Roberto Sanz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(37):12889-12893
A cascade reaction of indoles with propargylic diols involving an unprecedented metal‐free 1,2‐indole migration onto an alkyne was carried out. DFT calculations support a mechanism consisting of a concerted nucleophilic attack of the indole nucleus with loss of water, followed by the 1,2‐migration and subsequent Nazarov cyclization. This Brønsted acid‐catalyzed protocol affords indole‐functionalized benzofulvene derivatives in high yields. 相似文献
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《Helvetica chimica acta》2017,100(3)
The reaction of indoles and stabilized cyclopropyl alkynes under gold‐ and/or gold & Brønsted acid‐catalysis provided access to highly substituted tetrahydrocarbazoles. A mechanistic study revealed the complex mechanism underlying these processes and the opportunistic cooperation of Lewis and Brønsted acid‐catalysts towards the formation of complex molecular scaffolds. 相似文献