- Superbase-Mediated Indirect Friedl?nder Reaction: A Transition Metal-Free Oxidative Annulation toward Functionalized Quinolines
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A superbase mediated indirect Friedl?nder reaction towards functionalized quinolines has been realized. The reaction was performed with o-aminobenzyl alcohol and ketones having an active methylene moiety in the presence of KOH and in DMSO. The reaction proceeds predominantly via initial formation of an imine intermediate and subsequent oxidation of the benzyl alcohol functionality and condensation to afford substituted quinolines. We could also demonstrate that a minor fraction of the reaction proceeds via a chalcone intermediate. The transition metal-free oxidative annulation was found to be general affording 2-substituted, 2,3-disubstituted/fused or multi-substituted quinolines. The reaction was extended towards the functionalization of natural products and the applicability of the reaction for gram-scale synthesis of quinolines was also demonstrated.
- Rahul,Nitha,Omanakuttan, Vishnu K.,Babu, Sheba Ann,Sasikumar,Praveen, Vakayil K.,Hopf, Henning,John, Jubi
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p. 3081 - 3089
(2020/05/08)
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- An efficient synthesis of quinolines via copper-catalyzed C-N cleavage
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An efficient method to synthesize substituted quinolines from ketones and 2-amino benzylamines is described. Copper-catalyzed C-N cleavage of amines followed by condensation with ketones deliver quinolines in moderate to high yields. The broad scope of su
- Xi, Long-Yi,Zhang, Ruo-Yi,Zhang, Lei,Chen, Shan-Yong,Yu, Xiao-Qi
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p. 3924 - 3930
(2015/03/30)
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- Novel formation of oxazepino[4,5-a]quinolines by tandem 1,3-dipolar and insertion reaction of quinoline N-oxides with arynes
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By combination of 1,3-dipolar cycloaddition and N-O single bond insertion, tandem synthesis of dibenzo[1,4]-oxazepino[4,5-a]quinolines was accomplished. Reaction of quinoline N-oxides with arynes afforded 2-(2-hydroxyphenyl) quinolines and 7-membered pentacyclic oxazepino[4,5-a]quinolines.
- Okuma, Kentaro,Hirano, Koki,Shioga, Chisato,Nagahora, Noriyoshi,Shioji, Kosei
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p. 615 - 619
(2013/07/27)
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- Synthesis, characterization and photoluminescence properties of strong fluorescent BF2 complexes bearing (2-quinolin-2-yl)phenol ligands
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Novel N,O bidentate BF2 complexes were prepared in good to excellent yields through the coordination of (2-quinolin-2-yl)phenol and its derivatives with boron trifluoride etherate under mild conditions. These fluorine-boron complexes exhibited strong fluorescence both in organic solvents and in solid state. Their photophysical properties were thoroughly studied by absorption and fluorescence spectroscopy in various solvents. The electronic and site effects of substituents on phenolic and quinolinyl rings were found to have a profound impact on quantum yields. All these complexes were fully characterized by IR, 1H, 13C, 19F NMR and microanalysis. The high quantum yields and large Stokes shifts make these compounds as potential fluorescent dyes.
- Ma, Ru-Zheng,Yao, Qi-Chao,Yang, Xi,Xia, Min
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scheme or table
p. 93 - 98
(2012/05/19)
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- Regioselective synthesis of 2-(2-hydroxyaryl)pyridines from the reactions of benzynes with pyridine N-oxides
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By modifying the conditions from those in Larock's reported synthesis of 3-(2-hydroxyaryl)pyridines from benzynes, and pyridine N-oxides, we altered the regioselectivity of the reaction toward an efficient synthesis of 2-substituted pyridines. The presenc
- Shaibu, Balagopal S.,Kawade, Rahul Kisan,Liu, Rai-Shung
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p. 6834 - 6839
(2012/11/07)
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- Fluorescence sensing properties of 2-(2'-Hydroxyphenyl)quinoline and derivatives
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Novel chemosensors based on 2-(2'-hydroxyphenyl)quinoline were prepared and evaluated for sensing metal cations. The photophysical properties of chemosensors 1-3 were examined and their ion-selectivity was evaluated by measuring their fluorescent emission
- Helal, Aasif,Lee, Sang Hoon,Ren, Wen Xiu,Cho, Chan Sik,Kim, Hong-Seok
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experimental part
p. 1599 - 1603
(2011/12/14)
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- Reductive coupling reactions of 2-nitrochalcones and their β-hydroxy-analogues: New syntheses of 2-arylquinoline and 2-aryl-4-hydroxyquinoline derivatives
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A one-pot synthesis of novel 2-arylquinolines and 2-aryl-4- hydroxyquinolines was developed from the intramolecular reductive coupling reactions of 2-nitrochalcones and 3-hydroxy-1-phenyl-3-(2-nitrophenyl)-2-propen- 1-ones. Depending on the reduction method and on the presence of electron donating substituents on the A ring of 2-nitrochalcones one can modulate the formation of 2-arylquinolines, their N-oxides, and of 2-aminochalcones. The reduction of 3-hydroxy-1-(2-hydroxyphenyl)-3-(2-nitrophenyl)-2-propen-1-ones with stannous chloride in hydrochloric acid gave 2′-aminoflavones and with ammonium formate and Pd/C yielded 2-(2-hydroxyaryl)-4-hydroxyquinolines. Springer-Verlag 2007.
- Barros, Ana I.R.N.A.,Dias, Andre F. R.,Silva, Artur M. S.
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p. 585 - 594
(2008/02/03)
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- Radical dearomatization of arenes and heteroarenes
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The stannane-mediated benzeneselenol-catalyzed addition of aryl iodides to a range of arenes and aromatic hetereocycles has been studied. With furan, thiophene, and several carbocyclic arenes, the addition takes place with quenching of the adduct radical by the catalytic selenol leading to moderate yields of aryl-dihydroarenes. With nitrogen heterocycles, on the other hand, it was not possible to suppress aromatization of the adduct radical and fully aromatized products were isolated. Aryl iodides bearing hydrogen bond donating groups in the ortho-position add to nitrogen heterocycles with high selectivity ortho- to the nitrogen, affording a simple one-step synthesis of potential chelating ligands. While 2-iodophenol is an excellent aryl radical source in these reactions, the homologous 1-iodo-2-naphthol fails owing to its reaction with diphenyl diselenide, which gives 1-phenylseleno-2-naphthol in high yield.
- Crich, David,Patel, Mitesh
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p. 7824 - 7837
(2007/10/03)
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- One-pot synthesis of 2-(2-hydroxyaryl)quinolines: Reductive coupling reactions of 2′-hydroxy-2-nitrochalcones
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A one-pot synthesis of novel 2-(2-hydroxyaryl)quinolines have been developed from the intramolecular reductive coupling reactions of 2′-hydroxy-2-nitrochalcones, induced by stannous chloride in acidic medium (HCl/AcOH). In some cases these transformations can be performed with ammonium formate/Pd-C in methanol.
- Barros, Ana I. R. N. A.,Silva, Artur M. S.
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p. 5893 - 5896
(2007/10/03)
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- Ruthenium-catalysed oxidative cyclisation of 2-aminobenzyl alcohol with ketones: modified Friedlaender quinoline synthesis
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2-Aminobenzyl alcohol is oxidatively cyclised with an array of ketones in dioxane at 80 deg C in the presence of a catalytic amount of a ruthenium catalyst and KOH to afford the corresponding quinolines in high yields.
- Cho, Chan Sik,Kim, Bok Tae,Kim, Tae-Jeong,Shim, Sang Chul
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p. 2576 - 2577
(2007/10/03)
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