共查询到20条相似文献,搜索用时 15 毫秒
1.
An efficient and clean reaction process was developed for the convenient and cheap synthesis of spirooxindole derivatives. One-pot reactions of isatins, malononitrile (or ethyl cyanoacetate), hydrazine hydrate (or phenylhydrazine), and 1,3-dicarbonyl compounds were compared with one-pot reactions of isatins, malononitrile (or ethyl cyanoacetate), and 5-pyrazolone derivatives. Both sets of reaction were conducted in EtOH in the presence of 4-DMAP catalyst. A series of spiro[indoline-3,4′-pyrano[2,3-c]pyrazole] derivatives were quickly obtained in excellent yields by using the four-component one-pot reaction method. 相似文献
2.
A convenient route for the synthesis of 3,4-dihydrocoumarin derivates from salicylaldehyde derivates and 1,3-dicarbonyl compounds under solvent-free microwave irradiation conditions was described. In this way, a range of compounds was obtained in moderate to good yields in a short reaction time. 相似文献
3.
An efficient and facile one-pot synthesis is described for the preparation of novel tricyclic fused pyranothiazolopyrimidines containing both biologically active thiazolopyrimidine and pyranopyrimidine templates via three-component reaction involving an isocyanide with a dialkylacetylenedicarboxylate (DAAD) and 2,3-dihydro-5H-[1,3]thiazolo[3,2-a]pyrimidine-5,7(6H)-dione, in high yields. 相似文献
4.
A novel synthesis of 1,2,4-oxadiazoles is described from a one-pot, three-component reaction between nitriles, hydroxylamine, and aldehydes under microwave irradiation and solvent-free conditions in excellent yields. 相似文献
5.
A one-pot reaction sequence of sequential phosphine-promoted tandem annulations of aryl trifluoromethyl ketones and MBH (Morita-Baylis-Hillman) carbonates and DBU-mediated aminolysis was developed. This method provides a step-economical approach to trifluoromethylated dienamides with diverse structural complexity from readily available starting materials in moderate yields. 相似文献
6.
A novel one-pot, multi-component diastereoselective synthesis of functionalized cyclopenta[c]chromenes is described. This transformation proceeds via a Michael addition-cyclization reaction sequence between trialkyl phosphites, dialkyl acetylenedicarboxylates and in situ generated 2-(1-(2-oxo-2H-chromen-3-yl)alkylidene)malononitriles from the condensation of 3-acyl-2H-chromen-2-ones and malononitrile. 相似文献
7.
A very short and efficient synthesis of (−)-centrolobine has been achieved by using two successive one-pot reactions. The first sequence involves a cross-metathesis reaction/hydrogenation/lactonization and the second sequence is a Grignard addition/reduction. 相似文献
8.
(2-Amino-3-cyano-4H-chromen-4-yl) phosphonic acid diethyl esters are prepared via a single-step multi-component reaction of structurally diverse salicylaldehydes with malononitrile and triethyl phosphite using a catalytic amount of potassium phosphate in ethanol at ambient temperature. Use of potassium phosphate as an inexpensive catalyst makes the protocol more economical. Mild reaction conditions, simple work-up procedure are the added advantages of the present method. 相似文献
9.
Thelagathoti Hari Babu 《Tetrahedron letters》2010,51(6):994-5307
One-pot synthesis of novel spirocyclic oxindoles was achieved via vinylogous Michael addition of vinyl malononitriles on isatin-malononitrile adducts as the key step followed by a sequential tandem reaction. 相似文献
10.
Sundaravel Vivek Kumar Mani Anusha Rani Abdulrahman I. Almansour Raju Suresh Kumar S. Athimoolam Raju Ranjith Kumar 《Tetrahedron》2018,74(35):4569-4577
A facile syntheses of novel poly-substituted pyridine/benzo fused cyclododecane hybrid heterocycles have been achieved through one-pot multi-component tandem strategy employing cyclododecanone, aromatic aldehydes and malononitrile. 相似文献
11.
Toyoharu Kobayashi 《Tetrahedron letters》2008,49(28):4349-4351
A novel and useful method for the synthesis of 2-arylpyridines with a high efficiency and generality was achieved by utilizing the one-pot 6π-azaelectrocyclization followed by a base treatment. This is the first example of applying a sulfonamide to the azaelectrocyclization for efficient substituted pyridine synthesis. 相似文献
12.
《Tetrahedron letters》2017,58(3):218-222
We report herein a one-pot synthesis of unsymmetrical disulfides with trichloroisocyanuric acid (TCCA) as an oxidant. Under facile conditions, aromatic-aromatic disulfides and aromatic-aliphatic disulfides were synthesized in good to excellent yields even without base. For the construction of the challenging aliphatic-aliphatic disulfides, good yields of the desired products were also obtained with slightly modified conditions. Additionally, the reactions demonstrated a wide range of substrate scope, very short reaction time (<5 min), and convenient procedures. 相似文献
13.
A convenient one-pot method for the preparation of substituted 2-amino-1,3,4-oxadiazoles has been developed. The method is a significant improvement over previously reported syntheses. Reaction of carboxylic acids with thiosemicarbazides afforded the corresponding oxadiazoles in moderate to good yields. In general, the products precipitated from the reaction mixture, and were collected by filtration. In most of the cases, no chromatographic separations were required. To explore the scope and limitations of this reaction, various aliphatic, aromatic, and heteroaromatic carboxylic acids were reacted with different substituted thiosemicarbazides. The influence of R1 and R2 substituents on the reaction yield and additional results demonstrating the versatility of this method are presented. 相似文献
14.
An electrochemical strategy to the assembly of tricyclic spiro dihydrofuran scaffold via the reaction of aryl aldehyde and dimedone has been developed successfully. This protocol has the advantages of high yields, wide application scope and an environmental benign procedure compared with the reported methods. 相似文献
15.
Hui ChenDaqing Shi 《Tetrahedron》2011,67(31):5686-5692
An efficient one-pot synthesis of spiro[indoline-3,4′-pyrazolo[3,4-e][1,4]thiazepine] dione derivatives via three-component reaction of 5-amino-3-methylpyrazole, isatin, and thioacid is described. This new protocol produces novel heptacyclic spirooxindole derivatives in good yields in comparison to conventional pentacyclic compounds. This method proceeds through a 3-(5-aminopyrazol-3-yl)-3-hydroxy-2-oxindoline intermediate (Baylis-Hillman type adduct), unlike 3-indolylimine (the intermediate like Shiff-Bases) as in conventional methods. The structure of one representative compound has been confirmed by X-ray diffraction analysis. 相似文献
16.
In this work, a new series of 1,2,4,5-tetrahydro-2,4-dioxobenzo[b][1,4]diazepine and malonamide derivatives have been synthesized using an aromatic 1,2-diamine, Meldrum's acid, an isocyanide, and an arylidene malononitrile (or an aldehyde and malononitrile instead of an arylidene malononitrile) in CH2Cl2 at ambient temperature. Synthesis of 1,2,4,5-tetrahydro-2,4-dioxobenzo[b][1,4]diazepine proceeded via four- and five-component reactions; while the synthesis of malonamide derivatives was performed using five- and six-component reactions. In addition, a new series of the malonamide derivatives have been prepared using an aldehyde, malononitrile, Meldrum's acid, an isocyanide, and two molecules of 1,4-diamine via a six-component reaction. These procedures provide alternative methods to the synthesis of a new series of 1,2,4,5-tetrahydro-2,4-dioxobenzo[b][1,4]diazepine and malonamide derivatives. 相似文献
17.
A rapid one-pot solvent-free procedure has been developed for the synthesis of fluorinated 2,3-disubstituted quinazolin-4(3H)-ones by neat three-component cyclocondensation of anthranilic acid, phenyl acetyl chloride and substituted anilines under microwave irradiation. The experimental methodology and microwave conditions described here are well established, allowing significant rate enhancement and good yields compared to conventional reaction conditions. The reaction is generalized for O, M & P substituted anilines to give quinazolin-4(3H)-ones. Synthesized compounds have been screened for their antifungal activity. 相似文献
18.
Amol Maruti Jadhav Yeong Il Kim Kwon Taek Lim Yeon Tae Jeong 《Tetrahedron letters》2018,59(6):554-557
A simple, efficient, eco-friendly, and cost-effective method has been developed for the synthesis of N-methyl-3-nitro-aryl-benzo[4,5]imidazo[1,2-a]pyrimidin-2-amine derivatives using 2-aminobenzimidazole, aldehydes and (E)-N-methyl-1-(methylthio)-2-nitroethenamine, in the presence of catalytic amount of p-toluenesulfonic acid (p-TSA) in ethanol at 80?°C conditions. The advantages of this method are the use of an inexpensive and readily available catalyst, shorter reaction times, a wide range of functional group tolerance, and high yield of products via a simple experimental and work-up procedure. 相似文献
19.
Antimony trichloride (SbCl3) was found to be an efficient catalyst for the inverse electron demand imino Diels-Alder reactions of in situ generated N-benzylidenes with 3,4-dihydro-2H-pyran and 2,3-dihydrofuran to afford pyrano and furano[3,2-c]quinolines in excellent yields. 相似文献
20.
Eder J. Lenardão Samuel R. Mendes Gelson Perin Raquel G. Jacob 《Tetrahedron letters》2006,47(42):7439-7442
A general and easy method for the synthesis of several selenonium and telluronium salts is described. These compounds are acidic liquids at room temperature and were obtained in excellent yields. Phenyl butyl ethyl selenonium tetrafluoroborate was employed in the hetero-Diels-Alder cyclization of aryl imines derived from citronellal, affording octahydroacridines in good yields. 相似文献