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1.
Krystian Pluta 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2457-2475
Abstract Reactions of the 1,4-dithiin ring opening in 1,4-dithiinodiquinoline 1 with selected oxygen nucleophiles followed by S- and N-alkylation led to sulfides possessing one or two quinolinyl or quinolonyl units. Diquinolinyl sulfides 2 were transformed into quinolinyl-quinolonyl sulfides 3 or diquinolonyl sulfides 9 via thermal rearrangement (the O-N alkyl migration) or hydrolysis of the alkoxy and alkylthio groups with the hydrochloric acid-ethanol mixture. 相似文献
2.
1,8‐Diazabicyclo[5.4.0]undec‐7‐ene: A Highly Efficient Catalyst for One‐Pot Synthesis of Substituted Tetrahydro‐4H‐chromenes,Tetrahydro[b]pyrans,Pyrano[d]pyrimidines,and 4H‐Pyrans in Aqueous Medium
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Jitender M. Khurana Bhaskara Nand Pooja Saluja 《Journal of heterocyclic chemistry》2014,51(3):618-624
We have reported 1,8‐diazabicyclo[5.4.0]undec‐7‐ene catalyzed one‐pot synthesis of tetrahydro‐4H‐chromenes, tetrahydro[b]pyrans, pyrano[d]pyrimidines and 4H‐pyrans from aldehydes, active methylene compounds malononitrile/ethyl cyanocacetate and activated C–H acids such as dimedone, 1,3‐cyclohexanedione, 1,3‐cyclopentanedione, 1,3‐dimethylbarbituric acid, and ethyl acetoacetate in water under reflux. The attractive features of this process are mild reaction conditions, reusability of the reaction media, short reaction times, easy isolation of products, and excellent yields. Copyright © 2013 HeteroCorporation 相似文献
3.
Nüket Ocal Igdem Yolaan Eniz Kaban Vargas M. Leonor Vladimir Kouznetsov 《Journal of heterocyclic chemistry》2001,38(1):233-236
The Schiff bases derived from quinoline‐8‐carbaldehyde and substituted aromatic amines were used in the synthesis of C‐8 substituted quinolines. 3‐Aryl‐2‐(8‐quinolinyl)‐4‐thiazolidinones were prepared from obtained aldimines by means of the cyclocondensation of mercapto acids. A series of 4‐N‐arylamino‐4‐(8‐quinolinyl)‐1‐butenes was synthesized through the addition of the Grignard reagent (allylmagnesium bromide) to the double bond C=N of these aldimines. The structure of the prepared compounds was established on the basis of their elemental analyses and spectral data. 相似文献
4.
Mohammad Ali Bigdeli Katayon Marjani Elinaz Farokhi Enayatollah Sheikhhosseini Dadkhoda Ghazanfari 《Journal of heterocyclic chemistry》2013,50(3):625-629
In this paper, we describe a two‐step synthesis of a series of tacrine analogues. In the first step, α,α'‐bis(substituted‐benzylidene)cycloalkanones are reacted with malononitrile to afford 2‐amino‐3‐cyano‐4H‐pyrans. The second step involves the conversion of pyrans to pyrano[2,3‐b]pyridines with the use of AlCl3 as catalyst. 相似文献
5.
Ya Chen Yan‐Mei He Shanshan Zhang Tingting Miao Qing‐Hua Fan 《Angewandte Chemie (International ed. in English)》2019,58(12):3809-3813
A rapid construction of enantioenriched benzo‐fused quinolizidines, indolizidines, and their analogues by ruthenium‐catalyzed asymmetric cascade hydrogenation/reductive amination of quinolinyl‐ and quinoxalinyl‐containing ketones has been developed. This reaction proceeds under mild reaction conditions, affording chiral benzo‐fused aliphatic N‐heterocyclic compounds with structural diversity in good yields (up to 95 %) with excellent diastereoselectivity (up to >20:1 dr) and enantioselectivity (up to >99 % ee). Furthermore, this catalytic protocol is applicable to the formal synthesis of (+)‐gephyrotoxin. 相似文献
6.
Ya Chen Yan‐Mei He Shanshan Zhang Tingting Miao Qing‐Hua Fan 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(12):3849-3853
A rapid construction of enantioenriched benzo‐fused quinolizidines, indolizidines, and their analogues by ruthenium‐catalyzed asymmetric cascade hydrogenation/reductive amination of quinolinyl‐ and quinoxalinyl‐containing ketones has been developed. This reaction proceeds under mild reaction conditions, affording chiral benzo‐fused aliphatic N‐heterocyclic compounds with structural diversity in good yields (up to 95 %) with excellent diastereoselectivity (up to >20:1 dr) and enantioselectivity (up to >99 % ee). Furthermore, this catalytic protocol is applicable to the formal synthesis of (+)‐gephyrotoxin. 相似文献
7.
Efficient and Expeditious Synthesis of Pyrano‐pyrimidines,Multi‐substituted γ‐Pyrans,and Their Antioxidant Activity
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Khairy A. M. El‐Bayouki Wahid M. Basyouni Tamer K. Khatab Fakhry A. El‐Basyoni Ahmed R. Hamed Eslam A. Mostafa 《Journal of heterocyclic chemistry》2014,51(1):106-115
An efficient, expeditious catalytic route for the synthesis of ethyl 6‐amino‐5‐cyano‐2‐methyl‐4‐aryl‐4H‐pyran‐3‐carboxylates 2 was achieved via a three‐component, one‐pot reaction of malononitrile, ethyl acetoacetate, and various aromatic aldehydes in water as a solvent at room temperature. The key advantages are excellent yield, reaction time, and inexpensive catalyst. Also, cyclization of 4H‐pyrans 2 to the corresponding 4H‐pyrano[2,3‐d]pyrimidines 3 using silica sulfuric acid in the presence of acetic anhydride was described. Some synthesized compounds exhibited promising antioxidant activities. 相似文献
8.
Catalyst‐Directed Diastereo‐ and Site‐Selectivity in Successive Nucleophilic and Electrophilic Allylations of Chiral 1,3‐Diols: Protecting‐Group‐Free Synthesis of Substituted Pyrans
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Dr. Inji Shin Gang Wang Prof. Michael J. Krische 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(41):13382-13389
The iridium‐catalyzed, protecting group‐free synthesis of 4‐hydroxy‐2,6‐cis‐ or trans‐pyrans through successive nucleophilic and electrophilic allylations of chiral 1,3‐diols occurs with complete levels of catalyst‐directed diastereoselectivity in the absence of protecting groups, premetallated reagents, or discrete alcohol‐to‐aldehyde redox reactions. 相似文献
9.
Zinatossadat Hossaini Faramarz Rostami‐Charatib Rahimeh Hajinasiria Hojatollah Jafaryanc Mehdi Shahrakid 《Journal of heterocyclic chemistry》2012,49(2):402-404
A novel, convenient, and an efficient approach to the synthesis of 2H‐pyrans has been reported based on the multicomponent reaction. Solvent‐free condition for the reaction of dithiocarbamates, alkyl propiolates and isocyanides lead to the formation of 2H‐pyrans in good yields. In these reactions, synthesis of 2H‐pyrans is possible based on the one‐pot reaction and without using any catalyst. The mild reaction conditions and high yields of the products exhibit the good synthetic advantage of these methods. J. Heterocyclic Chem., lpar;2011). 相似文献
10.
An efficient, one‐pot method was described for the synthesis of various polysubstituted 4H‐pyrans via piperidine catalyzed three‐component condensation in aqueous medium. The reaction could be promoted effectively by adding sodium dodecyl sulfate to aqueous medium. J. Heterocyclic Chem., (2010). 相似文献
11.
An efficient multicomponent reaction of 3‐indolyl‐3‐oxopropanenitriles with dialkyl acetylenedicarboxylates and isocyanides under mild conditions leading to highly functionalized 6‐(indol‐3‐yl)‐4H‐pyrans in moderate to good yields has been developed. 相似文献
12.
Michel Frigoli Corinne Moustrou Andr Samat Robert Guglielmetti 《Helvetica chimica acta》2000,83(11):3043-3052
The synthesis of 3H‐naphtho[2,1‐b]pyrans linked to mono‐, di‐, or terthiophene via an acetylenic junction is described (Schemes 2 and 3). The synthetic approaches involve successive Sonogashira coupling reactions. The photochromic properties in solution of these novel materials were investigated under continuous irradiation. 相似文献
13.
14.
《Journal of heterocyclic chemistry》2018,55(4):964-970
Treatment of 2‐tosyloxybenzylidinethiosemicarbazone ( 2 ) with active halo compounds afforded thiazoles 3 – 5 . Moreover, reaction of compound 2 with acetic anhydride or dimethylformamide dimethylacetal gave N,N diacetyl 6 and dimethylamino derivatives 7 , respectively. Cyclization of thiazole derivatives 3 with some arylidenemalononitriles yielded thiazolo[2,3‐d]pyrans 8 – 12 . Multicomponent reaction of 2‐tosyloxybenzaldehyde ( 1 ) with urea, thiourea, or compound 2 and ethyl acetoacetate or acetylacetone afforded pyrimidines 13 – 14 . The structures of compounds were elucidated by elemental and spectral analyses. 相似文献
15.
Synthesis of 1‐Arylethyl‐2‐arylethylamino‐5‐trifluoroacetyl‐1,2,3,4‐tetrahydropyridines and Related Compounds with Potential Cell Efflux Pump Inhibition
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Nilo Zanatta Marcio M. Lobo Josiane M. dos Santos Laura de A. Souza Valquiria P. de Andrade Helio G. Bonacorso Marcos A. P. Martins 《Journal of heterocyclic chemistry》2015,52(6):1776-1781
This study reports a simple, fast, and efficient method for the synthesis of a new series of 1‐arylethyl‐2‐arylethylamino‐5‐trifluoroacetyl‐1,2,3,4‐tetrahydropyridines and related compounds from the reaction of 2‐alkoxy‐5‐trifluoroacetyl‐3,4‐dihydro‐2H‐pyrans with 2‐arylethanamines and related 2‐ethanamines. The desired tetrahydropyridines were obtained in excellent yields (90–98%), through a reaction that can be described as an AAB′ three‐component reaction protocol following an ANRORC‐type mechanism. 相似文献
16.
Copper complexes of chiral quinolinyl‐oxazoline have been studied as the catalysts for enantioselective allylic oxidation of cycloalkenes with tert‐butyl perbenzoate. Using 5 mol% of these chiral catalysts, optical active allylic benzoates were obtained in moderate enantiomeric excesses. CuOTf prepared in situ, CuClO4 and CuPF6 were found to be good precatalysts in acetone. 相似文献
17.
Katkar Santosh Shriram Lande Machhindra Karbhari Arbad Balasaheb Ramrao Gaikwad Suresh Tukaram 《中国化学》2011,29(1):199-202
4H‐Benzo[b]pyrans was synthesized under reflux condition in ethanol via condensation of benzaldehyde, malononitrile and dimedone with ZnO‐beta zeolite as an inexpensive and effective catalyst. The key features of the reported protocols are good to excellent yields, short reaction time and recovery and reusability of catalytic material. 相似文献
18.
Development of an Iron(II)‐Catalyzed Aerobic Catechol Cleavage and Biomimetic Synthesis of Betanidin
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Dr. Nicolas Guimond Dr. Peter Mayer Prof. Dr. Dirk Trauner 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(31):9519-9523
An aerobic iron(II)‐catalyzed cleavage of catechols was developed. This reaction allows for the preparation of 2‐methoxy‐2 H‐pyrans that can be employed as versatile building blocks for synthesis. The utility of this biomimetic oxidative cleavage is featured in the synthesis of betanidin, a natural colorant with antioxidant properties. 相似文献
19.
《Journal of heterocyclic chemistry》2017,54(2):1437-1441
Some new derivatives of 3,5‐diaryl‐4‐imino‐5,7,8,9‐tetrahydro‐3H‐chromeno[2,3‐d ]pyrimidine have been prepared through a condensation reaction of 2‐amino‐4‐aryl‐3‐cyano‐5,6,7,8‐tetrahydrobenzo[b ]pyrans with triethyl orthoformate in boiling acetic anhydride followed by cyclization with primary aryl amines in the presence of a few drops triethylamine as catalyst in refluxing ethanol. The products were characterized on the basis of IR, 1H‐NMR, and 13C‐NMR spectral and microanalytical data. 相似文献
20.
A new synthetic approach to the synthesis of some epimeric C‐4‐hydroxy‐benzo[c]pyrans is described. A key step in their formation is stereoisomerisation of a nonconjugated ortho alkenylphenylketone and ‐ester using palladium bisacetonitrile [bisacetonitriledichloropalladium(II)] to give the corresponding conjugated E stereoisomers which cyclize on treatment with meta‐chloroperbenzoic acid (m‐CPBA) to afford the target compounds. 相似文献