- Cyclic hydrazides 1. Synthesis of 4-hydroxy-1-oxo-1,2-dihydropyridazino[4,5-b]quinolines
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A series of dimethyl esters and cyclic hydrazides of quinoline-2,3-dicarboxylic acid has been synthesized with different substituents in the benzene ring.
- Rozhkov,Piskunova,Gol'd,Kalvin'sh
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- Selective reductive annulation reaction for direct synthesis of functionalized quinolines by a cobalt nanocatalyst
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Due to the extensive applications of quinolines, the search for selective construction of such products has long been an attractive subject in scientific community. Herein, by developing a new N-doped ZrO2@C supported cobalt nanomaterial, it has been successfully applied as an efficient catalyst for the reductive annulation of 2-nitroaryl carbonyls with alkynoates and alkynones. The catalytic transformation allows synthesizing a wide array of funcitonalized quinolines with the merits of broad substrate scope, good functional group tolerance, excellent hydrogen transfer selectivity, reusable earth-abundant metal catalyst, and operational simplicity. The developed chemistry paves the ways for further design of hydrogen transfer-mediated coupling reactions by developing heterogeneous catalysts with suitable supports.
- Xie, Rong,Lu, Guang-Peng,Jiang, Huan-Feng,Zhang, Min
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p. 239 - 243
(2020/02/15)
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- Regioselective Cyanation of Six-Membered N-Heteroaromatic Compounds Under Metal-, Activator-, Base- and Solvent-Free Conditions
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A regioselective cyanation of heteroaromatic N-oxides with trimethylsilyl cyanide has been developed to obtain 2-substituted N-heteroaromatic nitrile without the requirement of any external activator-, metal-, base-, and solvent. The present protocol is a straightforward, one-pot heteroaromatic C?H cyanation process, and proceeds smoothly in conventional heating but also under microwave irradiation with shorter reaction times. This approach now allows access to a broad class of quinoline N-oxides and other heteroarene N-oxides with high to good yields and can also be scaled up to obtain gram quantities. Further application of this process was observed and utilized in late-stage cyanation of the anti-malarial drug quinine as well as transformation of the 2-cyanoazines to a series of biologically important molecules. Based on the experimental observations, a plausible mechanism has also been proposed highlighting the dual role of trimethylsilyl cyanide as a nitrile source and as an activating agent. (Figure presented.).
- Sarmah, Bikash Kumar,Konwar, Monuranjan,Bhattacharyya, Dipanjan,Adhikari, Priyanka,Das, Animesh
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p. 5616 - 5625
(2019/11/22)
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- Metal-Free Oxidative Annulation/Cyclization of 1,6-Enynes for the Synthesis of 4-Carbonylquinolines
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Herein we report on the development of a metal-free oxidative annulation reaction of 1,6-enynes, leading to 4-carbonylquinolines by using dioxygen as a green sustainable oxidant. Key advances include the use of readily available tert-butyl nitrite (TBN) to promote radical annulation of 1,6-enynes and easy-to-handle reaction conditions. Preliminary mechanistic studies including radical capture reactions and isotope labelling experiments are also conducted. (Figure presented.).
- Xia, Xiao-Feng,He, Wei,Wang, Dawei
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supporting information
p. 2959 - 2964
(2019/04/30)
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- Visible-Light Induced and Oxygen-Promoted Oxidative Cyclization of Aromatic Enamines for the Synthesis of Quinolines Derivatives
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The dual transition metal-visible light photoredox catalysis for the synthesis of quinoline derivatives by using dioxygen as an oxygen source is developed. By using visible light, the direct oxidative cyclization of aromatic enamines with alkynes or alkenes can be achieved at mild conditions with an aid of copper or palladium catalysts, and a variety of multisubstituted quinoline derivatives could be obtained in good to moderate yields under mild reaction conditions.
- Xia, Xiao-Feng,Zhang, Guo-Wei,Wang, Dawei,Zhu, Su-Li
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p. 8455 - 8463
(2017/08/23)
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- One-pot and catalyst-free synthesis of pyrroloquinolinediones and quinolinedicarboxylates
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A method for the catalyst-free synthesis of pyrroloquinolinediones and quinolinedicarboxylates is developed through a one-pot synthesis involving denitrogenation of azide, benzisoxazole formation, aza-Diels-Alder cycloaddition, and dehydrative aromatization. Only stoichiometric amounts of N2 and H2O are produced as by-products. A comprehensive green chemistry metrics analysis indicated that this method is much more efficient and greener than two reported methods for the synthesis of pyrroloquinolinediones.
- Zhang, Xiaofeng,Dhawan, Gagan,Muthengi, Alex,Liu, Shuai,Wang, Wei,Legris, Marc,Zhang, Wei
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supporting information
p. 3851 - 3855
(2017/08/22)
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- Copper-Catalyzed Aerobic Oxidative Carbocyclization Reactions of N -[(E)-Stilben-2-yl]amine Derivatives
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A synthetic method for highly functionalized 2-quinolinones and quinolines has been developed. The copper(II)-catalyzed aerobic oxidative carbocyclization reactions of α-substituted N-[(E)-stilben-2-yl]acetamides, via the intramolecular carbocupration onto the alkenyl moiety, produced 3-substituted 2-quinolinones. Several useful functional groups including benzoyl, acetyl, cyano, and ethoxycarbonyl groups are compatible with the reaction conditions. This strategy was further applied to N-[(E)-stilben-2-yl]enamines to prepare 2,3-disubstituted quinolines in good yields.
- Lu, Cheng-Yen,Chuang, Che-Ping
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supporting information
p. 3687 - 3700
(2015/11/28)
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- InCl3-driven regioselective synthesis of functionalized/ annulated quinolines: Scope and limitations
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The efficient, regioselective synthesis of functionalized/annulated quinolines was achieved by the coupling of 2-aminoaryl ketones with alkynes/active methylenes/α-oxoketene dithioacetals promoted by InCl 3 in refluxing acetonitrile as well as under solvent-free conditions in excellent yields. This transformation presumably proceeded through the hydroamination-hydroarylation of alkynes, and the Friedlaender annulation of active methylene compounds and α-oxoketene dithioacetals with 2-aminoarylketones. In addition, simple reductive and oxidative cyclization of 2-nitrobenzaldehyde and 2-aminobenzylalcohol, respectively, afforded substituted quinolines. Systematic optimization of the reaction parameters allowed us to identify two-component coupling (2CC) conditions that were tolerant of a wide range of functional groups, thereby providing densely functionalized/annulated quinolines. This approach tolerates the synthesis of various bioactive quinoline frameworks from the same 2-aminoarylketones under mild conditions, thus making this strategy highly useful in diversity-oriented synthesis (DOS). The scope and limitations of the alkyne-, activated methylene-, and α-oxoketene dithioacetal components on the reaction were also investigated.
- Chanda, Tanmoy,Verma, Rajiv Kumar,Singh, Maya Shankar
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supporting information; experimental part
p. 778 - 787
(2012/06/29)
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- Pyridazinedione compounds useful in treating neurological disorders
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The present invention relates to pyridazino[4,5-b]quinolines, and pharmaceutically useful salts thereof, which are excitatory amino acid antagonists and which are useful when such antagonism is desired such as in the treatment of neurological disorders. The invention further provides pharmaceutical compositions containing pyridazino[4,5-b]quinolines as active ingredient, and methods for the treatment of neurological disorders.
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- FORMATIONS OF AZAZULANONES AND DIHYDROAZAZULANONES VIA REACTIONS OF TROPONIMINES WITH HETEROCUMULENES
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Reactions of troponimines with carbon disulfide, phenyl isocyanate, tosyl isocyanate, or diphenylketene afforded dihydroazazulanone and azazulanone derivatives through -type cycloadducts.Reaction with dimethyl acetylenedicarboxylate gave a dihydroazazulene derivative and a quinoline derivative.
- Ito, Kazuaki,Hara, Yasushi,Sakakibara, Reiji,Saito, Katsuhiro
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p. 1675 - 1682
(2007/10/03)
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- Regioselective Synthesis of Camptothecin
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A convergent synthesis of (+/-)camtothecin is described.
- Rao, A. V. Rama,Yadav, J. S.,Valluri, Muralikrishna
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p. 3613 - 3616
(2007/10/02)
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- Alkyl esters of substituted 2-methyl-3-quinolinecarboxylic acid and quinoline-2,3-dicarboxylic acid: dialkyl 3-(substituted)phenylaminobut-2-ene-dioates and methods for the preparation thereof
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There are provided novel alkyl esters of substituted 2-methyl-3-quinolinecarboxylic acid and quinoline-2,3-dicarboxylic acid; novel dialkyl 3-(substituted)phenylaminobut-2-ene-dioates, useful as intermediates for the preparation of highly effective 2-(2-imidazolin-2-yl)quinoline herbicidal agents and methods for the preparation thereof.
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- 2-(2-imidazolin-2-yl)-pyridines and quinolines, process and intermediates for the preparation thereof, and use of said compounds as herbicidal agents
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There are provided novel 2-(2-imidazolin-2-yl)pyridine and quinoline compounds, a process and intermediate compounds for the preparation thereof, and a method for controlling a wide variety of annual and perennial plant species therewith.
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- Alkyl esters of substituted 2-methyl-3-quinolinecarboxylic acid and quinoline-2,3-dicarboxylic acid
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There are provided novel alkyl esters of substituted 2-methyl-3-quinolinecarboxylic acid and quinoline-2,3-dicarboxylic acid; novel dialkyl 3-(substituted)phenylaminobut-2-ene-dioates, useful as intermediates for the preparation of highly effective 2-(2-imidazolin-2-yl)quinoline herbicidal agents and methods for the preparation thereof.
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- Process for the preparation of 2,3-quinolinedicarboxylic acids
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There is provided a novel process for the preparation of a substituted or unsubstituted 2,3-quinolinedicarboxylic acid, utilizing as the starting material, 2-methyl-3-quinolinecarboxylic acid or 3-methyl-2-quinolinecarboxylic acid or the alkyl ester of either of the above compounds.
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- REACTIONS OF 2,1-BENZISOTHIAZOLES WITH ACETYLENIC ESTERS
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2,1-Benzisothiazole and the 3-methyl derivative react with dimethyl acetylenedicarboxylate (DMAD) under forcing conditions by addition across the heterodiene and loss of sulphur to afford dimethyl quinoline-2,3-dicarboxylate and the corresponding 4-methyl derivative, respectively.Diethyl acetylenedicarboxylate and methyl propiolate react similarly but in very low yield.These reactions could involve initial Michael-type attack of the acetylenic ester on the heterocyclic nitrogen or concerted cycloaddition. 3-Amino-2,1-benzisothiazole and DMAD react differently to yield dimethyl 2-cyanoanilinofumarate; a possible mechanism is presented.
- Bryce, Martin R.,Acheson, R. Morrin,Rees, Anthony J.
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p. 489 - 495
(2007/10/02)
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