共查询到20条相似文献,搜索用时 15 毫秒
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A highly chemoselective heteroannulation protocol for the synthesis of unreported polysubstituted heterocyclic [3.3.3]propellanes has been developed by sequential four-component reaction of ninhydrin, malononitrile, primary amines, and dialkyl acetylenedicarboxylates under mild conditions in water. To the best of our knowledge, there are no previous reports for the synthesis of these classes of heterocyclic [3.3.3]propellanes. The merit of this sequential Knoevenagel condensation/enamine formation/Michael addition/cyclization sequence is highlighted by its high atom-economy, excellent yields, the use of water as reaction media, and the efficiency of production without the use of any activator or metal promoters. This synthesis serves as a nice addition to group-assistant-purification (GAP) chemistry in which purification via chromatography and recrystallization can be avoided, and the pure products were obtained simply by washing the crude products with 95% ethanol. 相似文献
3.
Maciej Dawidowski Franciszek Herold Marcin Wilczek Jadwiga Turło Andrzej Chodkowski Anna Gomółka Jerzy Kleps 《Tetrahedron》2012,68(39):8222-8230
A three-step sequence involving an Ugi five-center, four-component reaction (U-5C-4CR), amide N-detertbutylation and cyclocondensation has been developed for easy access to diverse bicyclic 2,6-diketopiperazine (2,6-DKP) derivatives. In the key step, aromatic aldehydes were successfully coupled with cyclic α-amino acids and isocyanides in the course of U-5C-4CR. Boron trifluoride-acetic acid complex was developed as a new N-detertbutylating agent effective at rt. 相似文献
4.
An efficient one-pot synthesis of pyrimido[6,1-a]isoquinoline-1-carboxylate derivatives is described. This involves the four-component reaction between primary amines, alkyl acetoacetates, isoquinoline and trichloromethylchloroformate (diphosgene) under mild conditions at ambient temperature. 相似文献
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A simple and versatile procedure for the combinatorial synthesis of (Z)-dialkyl-5-(alkylimino)-5Hspiro[ furan-2,11'-indeno[1,2-b]quinoxaline]-3,4-dicarboxylates via the catalyst-free one-pot fourcomponent reaction of ninhydrin, benzene-1,2-diamines, dialkyl acetylenedicarboxylates and isocyanides is described. 相似文献
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A tandem four-component reaction of 2-bromobenzaldehyde, alkyne, amine, and diethyl phosphite catalyzed by the combination of palladium and copper salts provides a facile and efficient route to 1,2-dihydroisoquinolin-1-ylphosphonate. A cascade Sonogashira-intramolecular cyclization-nucleophilic addition may be involved in the reaction process. 相似文献
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Substituted 2-oxazolines of the general structure shown above are found in several families of bioactive natural products and can be prepared in an efficient and general one-pot, four-component condensation. 相似文献
8.
[reaction: see text] Alicyclic beta-lactams were successfully synthesized via a parallel liquid-phase Ugi four-center three-component reaction (U-4C-3CR), starting from alicyclic beta-amino acids such as cis-2-aminocyclohexanecarboxylic acid, cis-2-aminocyclopentanecarboxylic acid, 2,3-diexo-3-aminobicyclo[2.2.1]heptane-2-carboxylic acid and some of their partially unsaturated analogues. A six-membered mixture-based combinatorial library of beta-lactams was also generated. 相似文献
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An efficient one-pot four-component condensation reaction of acenaphthoquinone, pyrazolones or barbituric acid and 1,1-bis(methylthio)-2-nitroethene and alkylamines in ethanol for the synthesis of novel spiro[acenaphthylene-1,4′-pyrano[2,3-c]pyrazol]-2-one and spiro[acenaphthylene-1,5′-pyrano[2,3-d]pyrimidine]-trione is descibed. The significant features of this method include, readily available starting materials, operational simplicity, green solvent, catalyst-free condition, no column chromatographic purification and good to high yields. 相似文献
10.
Ahmad Shaabani Mozhdeh Seyyedhamzeh Ali Maleki Maryam Behnam Fahimeh Rezazadeh 《Tetrahedron letters》2009,50(24):2911-4167
A one-pot four-component reaction of an aliphatic or aromatic amine, diketene, an aromatic aldehyde and 1,3-diphenyl-1H-pyrazol-5-amine in the presence of p-toluenesulfonic acid as a catalyst has been developed. In this reaction, a new class of fully substituted pyrazolo[3,4-b]pyridine-5-carboxamide derivatives is produced under mild reaction conditions and in good yields at ambient temperature. 相似文献
11.
Mohammad Anary-Abbasinejad Hossein Anaraki-Ardakani Fatemeh Ghanea 《Monatshefte für Chemie / Chemical Monthly》2009,140(4):397-400
Abstract The reactive intermediate generated by the reaction of alkyl isocyanides and dialkyl acetylenedicarboxylates was trapped by
ethyl carbazones to produce stable ketenimine derivatives in good yield. The reaction is characterized by mild conditions,
high selectivity, and tolerance to various functional groups.
Graphical abstract
相似文献
12.
Didier CoffinierLaurent El Kaim Laurence Grimaud Eelco RuijterRomano V.A. Orru 《Tetrahedron letters》2011,52(23):3023-3025
The ketenimines resulting from a Nef isocyanide/Perkow sequence react with 1-azadienes to form pyridines or pyrimidines depending on their substitution pattern. The reaction is most efficient with ester-substituted ketenimines which leads to pyridines after elimination of the phosphate group. 相似文献
13.
R. S. Borisov A. I. Polyakov L. A. Medvedeva N. I. Guranova L. G. Voskressensky 《Russian Chemical Bulletin》2012,61(8):1609-1615
Tetrazolo[1,5-a][1,4]benzodiazepines were obtained by an efficient azide five-centered four-component Ugi reaction, which used ketones, sodium azide, ammonium chloride, and the corresponding isonitrile. Scope and limitations of this multi-component reaction were considered. 相似文献
14.
Waléria F. Rabêlo 《合成通讯》2019,49(4):515-521
In an attempt to further exploit multicomponent reactions in the field of 1,4 naphthoquinone-based compounds, we describe an Ugi-type multicomponent approach for the synthesis of novel 3-substituted 1,4 naphthoquinone molecules. The process relies on the execution of an enol-Ugi reaction between an enol-3-nitro-1,4 naphthoquinone with different secondary diamines and isocyanides. The novel methodology showed great chemical efficiency and versatility. 相似文献
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Reaction of pernosylated diethylenetriamine and 2-substituted propane-1,3-diols in dry THF in the presence of triphenylphosphine and diisopropyl azodicarboxylate gives the corresponding protected 9-substituted 1,4,7-triazacyclodecanes. The Mitsunobu reaction was also used in the preparation of 3-substituted 1,5,9-triazacyclododecanes and macrocyclic pyridine derivatives. 相似文献
16.
Seyed Mohammad VAHDAT Fereshteh CHEKIN Mehdi HATAMI Maryam KHAVARPOUR Saeed BAGHERY Ziba ROSHAN‐KOUHI 《催化学报》2013,34(4):758-763
Tin dioxide (SnO2 ) nanoparticles efficiently catalyzed unsymmetrical four-component Hantzsch condensations of various aldehydes, dimedone, ethyl acetoacetate, and ammonium acetate to form polyhydroquinoline derivatives in excellent yields. This novel method offers several advantages over the traditional method of synthesizing these compounds, including safety, mild conditions, short reaction times, high yields, and an easy workup. 相似文献
17.
Fereshteh Mousavizadeh Mahdiyeh Talebizadeh Mohammad Anary-Abbasinejad 《Tetrahedron letters》2018,59(31):2970-2974
A novel synthesis of indolylpyrrole derivatives is described by a four-component domino reaction between arylglyoxals, acetylacetone, indole and aliphatic amines in water as solvent at 60?°C without using any catalyst or promoter. The FT-IR, 1H NMR, 13C NMR spectral and elemental analysis confirm the structures of the products. 相似文献
18.
Angel Zamudio-Medina 《Tetrahedron letters》2010,51(37):4837-6361
A series of aza-analogs of nuevamine were prepared from readily available aldehyde, amine, and isonitrile compounds and maleic anhydride by combining a novel four-component reaction and free radical cyclization. The operational simplicity of this novel heterocycle synthesis process will be valuable for the synthesis of fused ring systems. 相似文献
19.
《合成通讯》2012,42(24):3453-3464
AbstractA new series of regioselective dispiropyrrolidine analogs via efficient one-pot four-component tandem reaction has been discovered. The reaction was carried out in the presence of four common reactants and magnesium silicate nanoparticles (NPs) in ethanol under microwave irradiation. The reaction proceeds rapidly and can be completed within 60–90?min. This methodology offers several significant advantages such as high yield, mild catalyst, and easy to perform. The synthesized compound was further screened for antibacterial and antiproliferative activities. The results showed that compound 5c and 5a were potent antibacterials against Gram-positive and Gram-negative bacteria. Further, 5a showed best antiproliferative activity against tested cell lines. 相似文献
20.
A number of new dialkyl 5-(aryl)-1-phenyl-1H-prazole-3,4-dicarboxylate derivatives have been prepared regiospecifically in moderate to good yield from the cyclocondensation reaction of dialkyl (E)-2-(dialkoxyphosphoryl)-3-(aroyl)-2-butenedioate, derived from the reaction between trimethyl phosphite, an acetylenic ester, and an aroyl chloride, with phenylhydrazine. The reaction is four-component and is carried out under reflux conditions in dry toluene. 相似文献