- Catalytic Acceptorless Dehydrogenation of Amino Alcohols and 2-Hydroxybenzyl Alcohols for Annulation Reaction under Neutral Conditions
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A base-free and acceptorless Ru-catalyzed dehydrogenative approach has been developed for the synthesis ofN-heterocycles by using 1,3-dicarbonyls and amino alcohols through a domino sequential enamine formation and intramolecular oxidative cyclization strategy. This unified approach is also applicable for the synthesis of O-heterocycles involving 2-hydroxybenzyl alcohol as a coupling reactant via consecutive C-alkylation and intramolecular cyclization steps. The present protocol is general for the synthesis of varieties of biologically important scaffolds, such as tetrahydro-4H-indol-4-one, 3,4-dihydroacridin-1(2H)-one, and tetrahydro-1H-xanthen-1-ones derivatives using a single catalytic system, viz. RuH2CO(PPh3)3. Environmentally benign H2O and H2are the only byproducts in this domino process. Moreover, RuH2CO(PPh3)3-catalyzed C3-alkylation of tetrahydro-4H-indol-4-one using alcohol as a alkylating partner is also described in this report. For the first time, a solvent-free gram-scale reaction for the acceptorless dehydrogenative annulation has been demonstrated. A plausible mechanism for the Ru-catalyzed base-free and acceptorless dehydrogenative annulation of amino alcohols or 2-hydroxybenzyl alcohols has been provided with several experimental investigations and spectroscopic evidence.
- Pandey, Akanksha M.,Digrawal, Naveen Kumar,Mohanta, Nirmala,Jamdade, Akash Bandu,Chaudhari, Moreshwar B.,Bisht, Girish Singh,Gnanaprakasam, Boopathy
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p. 8805 - 8828
(2021/07/20)
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- Fe2O3@[proline]–CuMgAl–LDH: A magnetic bifunctional copper and organocatalyst system for one-pot synthesis of quinolines and 2H-indazoles in green media
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A novel magnetic core–shell Fe2O3@[proline]–CuMgAl–L(ayered)D(ouble)H(ydroxide) was designed as an efficient bifunctional catalytic system. To this end, Cu (II) was combined with Mg and Al in the LDH structure and l-proline was intercalated between LDH layers in order to perform a straightforward synthesis of quinolines and 2H-indazoles as two important pharmaceutical N-aryl-substituted heterocyclic compounds. In this regard, a facile method was employed through consecutive condensation under a mild conditions in choline azide media, which played the role of a reagent and a solvent to avoid toxic solvents and hazardous azidation reagents. These techniques provided considerable improvement in terms of using green media, reducing starting materials, reaching higher yields and offering a shorter reaction time and lower temperature. In conclusion, it was found that the catalyst could be reused five times with no significant loss of activity.
- Esfandiary, Naghmeh,Heydari, Akbar
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- Synthesis of quinolines: Via copper-catalyzed domino reactions of enaminones
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Quinoline derivatives were obtained from enaminones and 2-bromo- or 2-iodobenzaldehydes via copper-catalyzed domino reactions consisting of the aldol reaction, C(aryl)-N bond formation and elimination. The electronic effect of aldehydes played a major role in the reaction outcome. Two simple protocols are disclosed to achieve various quinolines from both cyclic and acyclic enaminones in good yields. With the less-reactive acyclic enaminones, diethyl-2-(2-bromobenzylidene)malonate was shown to be more compatible than the benzaldehydes.
- Kaewmee, Benyapa,Rukachaisirikul, Vatcharin,Kaeobamrung, Juthanat
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p. 7387 - 7395
(2017/09/25)
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- Catalytic application of non-toxic Persia americana metabolite entrapped SnO2 nanoparticles towards the synthesis of 3,4-dihydroacridin-1(2H)-ones
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Eco-friendly methods in organic synthesis are dynamic prerequisites for environmental safety. In general, metal nanoparticles displayed various levels of toxicity, photocatalytic activity and catalytic activity. Due to their diverse properties, recent wor
- Roopan, Selvaraj Mohana,Palaniraja, Jeyakannu,Elango, Ganesh,Arunachalam, Prabhakarn,Sudhakaran
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p. 21072 - 21075
(2016/03/05)
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- Ruthenium-catalysed C-alkylation of 1,3-dicarbonyl compounds with primary alcohols and synthesis of 3-keto-quinolines
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The mono-alkylation of 1,3-diketones using alcohols is possible in the presence of catalytic amounts of Ru(CO)(PPh3)3HCl and 10% mol of the Hantzsch ester. The borrowing hydrogen process between the catalyst and the dihydropyridine/p
- Cini, Elena,Petricci, Elena,Truglio, Giuseppina I.,Vecchio, Marialaura,Taddei, Maurizio
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p. 31386 - 31390
(2016/04/09)
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- Efficient Synthesis of Quinolines via a Knoevenagel/Staudinger/aza-Wittig Sequence
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A simple and efficient method for the construction of quinoline derivatives from 2-azidobenzaldehyde and various carbonyl compounds was developed. The process involves a Knoevenagel condensation of 2-azidobenzaldehyde with carbonyl compound and subsequently an intramolecular normal Staudinger/aza-Wittig reaction to form the quinolone ring in satisfactory yields.
- Qu, Feng,He, Ping,Hu, Ruo-Fei,Cheng, Xiao-Hong,Wang, Song,Wu, Jing
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supporting information
p. 2802 - 2809
(2015/12/23)
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- CuSO4-d-glucose, an inexpensive and eco-efficient catalytic system: Direct access to diverse quinolines through modified Friedl??nder approach involving SNAr/reduction/annulation cascade in one pot
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A highly efficient and scalable multicomponent domino reaction for the synthesis of functionalized/annulated quinolines is devised directly from 2-bromoaromatic aldehydes/ketones in H2O-EtOH mixture for the first time. The key to this reaction is the use of an air-stable, eco-efficient and inexpensive CuSO4-d-glucose catalyst system, which is able to catalyze multiple transformations in one pot. The approach is carbon-economic and relies on sequential SNAr/reduction/Friedl??nder annulation steps, forming C-C and C-N bonds by cleavage of the Csp2-Br bond in a single synthetic operation. The reaction has a broad substrate scope and affords products in good to excellent yields.
- Anand, Namrata,Chanda, Tanmoy,Koley, Suvajit,Chowdhury, Sushobhan,Singh, Maya Shankar
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p. 7654 - 7660
(2015/02/19)
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- Iron/acetic acid mediated intermolecular tandem C-C and C-N bond formation: An easy access to acridinone and quinoline derivatives
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An efficient iron/acetic acid mediated one pot reductive cyclization protocol was successfully developed for the synthesis of acridinone and quinoline derivatives. This highly efficient process proceeds under mild conditions, tolerates different functiona
- Rajawinslin,Gawande, Sachin D.,Kavala, Veerababurao,Huang, Yi-Hsiang,Kuo, Chun-Wei,Kuo, Ting-Shen,Chen, Mei-Ling,He, Chiu-Hui,Yao, Ching-Fa
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p. 37806 - 37811
(2014/11/07)
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- One-pot DBU-promoted synthesis of hydroacridinones and spirohexahydropyrimidines
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The potential hydroacridinone synthesis using simple and inexpensive starting materials, namely 1,3-dicarbonyl compounds, anilines, formaldehyde and DBU as a stoichiometric base was explored. As a result, from the reaction of 1,3-cyclohexanedione and dimedone tetrahydroacridinones were the main reaction products along with small yields of their oxidation products, the dihydroacridinones, whereas in the case of 2-acetylcyclohexanone spirohexahydropyrimidines were isolated in very good yields. Plausible mechanistic schemes for the formation of all products are proposed. Georg Thieme Verlag Stuttgart New York.
- Neochoritis, Constantinos G.,Eleftheriadis, Nicolaos,Tsiantou, Arianna,Stephanidou-Stephanatou, Julia,Tsoleridis, Constantinos A.
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p. 2768 - 2772
(2014/01/06)
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- An unexpected one-pot synthesis of multi-substituted quinolines via a cascade reaction of Michael/Staudinger/aza-Wittig/aromatization of ortho-azido-β-nitro-styrenes with various carbonyl compounds
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Multi-substituted quinolines 3 were unexpectedly prepared from a cascade reaction of ortho-azido-β-nitro-styrenes with various carbonyl compounds. This method takes advantages of mild condition, simple work-up, high yield as well as wide substrate scope, which makes this method powerful for one-pot synthesis of multi-substituted quinolines.
- Yu, Zhi-Hua,Zheng, Hu-Fei,Yuan, Wei,Tang, Zi-Long,Zhang, Ai-Dong,Shi, De-Qing
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p. 8137 - 8141
(2013/09/02)
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- Synthesis of quinolines via friedlaender reaction in water and under catalyst-free conditions
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A straightforward and efficient method for the synthesis of quinolines via Friedlaender reaction of 2-aminobenzaldehyde with various ketones or malononitrile in water without using any catalyst at 70 °C is reported. Georg Thieme Verlag Stuttgart New York.
- Shen, Qiang,Wang, Limin,Yu, Jianjun,Liu, Mingtao,Qiu, Jun,Fang, Lei,Guo, Fenglou,Tang, Jun
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supporting information; experimental part
p. 389 - 392
(2012/03/11)
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- Cerium(IV) ammonium nitrate is an excellent, general catalyst for the Friedlaender and Friedlaender-Borsche quinoline syntheses: Very efficient access to the antitumor alkaloid luotonin A
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(Figure Presented) The use of cerium(IV) ammonium nitrate as a catalyst of the Friedl€ander reaction allows the synthesis of polysubstituted quinoline derivatives in excellent yields, avoiding the traditional harshly basic or acidic conditions. Unlike most other previously known reagents, CAN allows double condensations and is also an excellent catalyst for the Borsche variation of the Friedlaender reaction, which has been applied to the very efficient synthesis of the antitumor alkaloid luotonin A.
- Sridharan, Vellaisamy,Ribelles, Pascual,Ramos, Ma. Teresa,Menendez, J. Carlos
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supporting information; experimental part
p. 5715 - 5718
(2009/12/06)
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- Palladium-catalyzed coupling of vinylogous amides with aryl halides: Applications to the synthesis of heterocycles
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Described herein is the first example of the palladium-catalyzed coupling of vinylogous amides with aryl bromides and chlorides. The scope of this reaction with respect to the aryl component is investigated. Additionally, a tandem reaction sequence in which the above coupling is followed by an intramolecular Heck reaction is presented. These reactions can be applied to high-yielding, one-pot syntheses of nitrogen-containing heterocycles.
- Edmondson, Scott D.,Mastracchio, Anthony,Parmee, Emma R.
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p. 1109 - 1112
(2007/10/03)
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- 3,3,6,6-tetramethyl-9-(2-nitrophenyl)-3,4,5,6,9,10-hexahydroacridine-1, 8(2H,7H)-dione
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The title compound, C23H26N2O4, consists of a partially hydrogenated acridine moiety with one 2-nitrophenyl substituent on the central ring. The acridine nucleus suffers considerable deviations from planarity. T
- Brito-Arias, Marco,Ramirez, Guadalupe,Rivas, Ruth E.,Molins, Elies,Maniukiewicz, Waldemar
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p. 2811 - 2814
(2007/10/03)
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- Synthesis of 3,4-dihydro-3,3-dimethyl-1(2H)-acridinone
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The acridinone derivative 3,4-dihydro-3,3-dimethyl-1(2H)-acridinone (4) has been prepared in a two step fashion and the molecular structure confirmed by X-ray diffraction.Compound 4 crystallizes in the space group P21/n with a = 6.022(2), b = 2
- Martinez, Roberto,Espinosa-Perez, Georgina,Brito-Arias, Marco
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p. 201 - 204
(2007/10/02)
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- Reaction of Enaminones with Carbon Disulfide: Synthesis of Heterocycles Using Enamino Dithiocarboxylates
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Reaction of various types of enaminones, which are prepared by the condensation of 1,3-dicarbonyl compounds with aromatic amines, with carbon disulfide in the presence of sodium hydroxide as the base in dimethyl sulfoxide to give the corresponding enamino
- Tominaga, Yoshinori,Okuda, Hiroto,Mazume, Hisako
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p. 1245 - 1256
(2007/10/02)
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