- Cu(I)-Catalyzed Alkynylation of Quinolones
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Herein we report the first alkynylation of quinolones with terminal alkynes under mild reaction conditions. The reaction is catalyzed by Cu(I) salts in the presence of a Lewis acid, which is essential for the reactivity of the system. The enantioselective version of this transformation has also been explored, and the methodology has been applied in the synthesis of the enantioenriched tetrahydroquinoline alkaloid cuspareine.
- Maestro, Aitor,Lemaire, Sebastien,Harutyunyan, Syuzanna R.
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supporting information
p. 1228 - 1231
(2022/02/14)
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- Cobalt(III)- and Rhodium(III)-Catalyzed C-H Amidation and Synthesis of 4-Quinolones: C-H Activation Assisted by Weakly Coordinating and Functionalizable Enaminone
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Cobalt(III) and rhodium(III) catalysts exhibited complementary scope in C-H amidation of aryl enaminones. The amidation reactions proceeded with broad scope under the assistance of a weakly coordinating and bifunctional enaminone directing group. The electrophilicity of the enaminone group can be further utilized in subsequent hydrolysis-cyclization reactions to afford NH 4-quinolones in telescoping reactions.
- Wang, Fen,Jin, Liang,Kong, Lingheng,Li, Xingwei
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supporting information
p. 1812 - 1815
(2017/04/11)
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- Synthesis of bridged benzazocines and benzoxocines by a titanium-catalyzed double-reductive umpolung strategy
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A sequence of two titanium(III)-catalyzed reductive umpolung reactions is reported that allows the rapid construction of benzazo- and benzoxozine building blocks. The first step is a reductive cross-coupling of quinolones or chromones with Michael acceptors. This reaction proceeds with complete syn-selectivity for the quinolone functionalization while the anti-diastereomers are obtained as the major products from chromones. With different reaction conditions, the stereochemical outcome can be altered to afford the syn-chromanone products as well. A subsequent reductive ketyl radical cyclization forges the tricyclic title compounds in good yields. A stereochemical model explaining the observed stereoselectivities is provided and the product configurations were unambiguously verified by X-ray analyses and 2D NMR spectroscopic experiments.
- Bichovski, Plamen,Haas, Thomas M.,Kratzert, Daniel,Streuff, Jan
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supporting information
p. 2339 - 2342
(2015/02/05)
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- Further studies on bis-charged tetraazacyclophanes as potent inhibitors of small conductance Ca2+-activated K+ channels
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Previously, quinolinium-based tetraazacyclophanes, such as UCL 1684 and UCL 1848, have been shown to be extraordinarily sensitive to changes in chemical structure (especially to the size of the cyclophane system) with respect to activity as potent non-peptidic blockers of the small conductance Ca 2+-activated K+ ion channels (SKCa). The present work has sought to optimize the structure of the linking chains in UCL 1848. We report the synthesis and SKCa channel-blocking activity of 29 analogues of UCL 1848 in which the central CH2 of UCL 1848 is replaced by other groups X or Y = O, S, CF2, CO, CHOH, CC, CHCH, CHMe to explore whether subtle changes in bond length or flexibility can improve potency still further. The possibility of improving potency by introducing ring substituents has also been explored by synthesizing and testing 25 analogues of UCL 1684 and UCL 1848 with substituents (NO2, NH2, CF 3, F, Cl, CH3, OCH3, OCF3, OH) in the 5, 6 or 7 positions of the aminoquinolinium rings. As in our earlier work, each compound was assayed for inhibition of the afterhyperpolarization (AHP) in rat sympathetic neurons, an action mediated by the SK3 subtype of the SK Ca channel. One of the new compounds (39, R7 = Cl, UCL 2053) is twice as potent as UCL 1848 and UCL 1684: seven are comparable in activity.
- Yang, Donglai,Arifhodzic, Lejla,Ganellin, C. Robin,Jenkinson, Donald H.
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p. 907 - 923
(2013/07/27)
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- Synthesis of 2,3-dihydro-4(1H)-quinolones and the corresponding 4(1H)-quinolones via low-temperature fries rearrangement of N-arylazetidin-2- ones
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N-Arylazetidin-2-ones of the general form 1, which are readily prepared by GoldbergBuchwald-type copper-catalyzed coupling of N-unsubstituted azetidin-2-ones with the relevant aryl halide or using Mitsunobu cyclization processes, undergo smooth Fries-rearrangement in triflic acid at 018°C to give the isomeric 2,3-dihydro-4(1H)-quinolones (2). Dehydrogenation of the latter compounds using 10% Pd on C in 1.0M aqueous sodium hydroxide/propan-2-ol mixtures at ca. 82°C provides the corresponding 4(1H)-quinolones (3).
- Lange, Jens,Bissember, Alex C.,Banwell, Martin G.,Cade, Ian A.
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experimental part
p. 454 - 470
(2011/10/09)
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- Direct C-3-alkenylation of quinolones via palladium-catalyzed C-H functionalization
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An unprecedented C-3-alkenylation of quinolones was reported through palladium-catalyzed C-H functionalization with 1% catalyst loading. This method provides an efficient route to a variety of new quinolone derivatives.
- Li, Mingzong,Li, Liangxi,Ge, Haibo
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supporting information; experimental part
p. 2445 - 2449
(2010/12/25)
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- Gas-phase pyrolysis in organic synthesis: Rapid green synthesis of 4-quinolinones
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Gas-phase pyrolysis of aminomethylene Meldrum's acid derivatives gave quinolinones and/or amines depending on the nature of arylamino moiety. Effect of substituent on reaction rate and nature of pyrolysis products supports the suggested intramolecular nucleophilic substitution reaction via initially formed keteneamine intermediate. Georg Thieme Verlag Stuttgart.
- Al-Awadi, Nouria A.,Abdelhamid, Ismail Abdelshafy,Al-Etaibi, Alya M.,Elnagdi, Mohamed Hilmy
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p. 2205 - 2208
(2008/02/10)
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- Solid-phase synthesis of 4(1H)-quinolone and pyrimidine derivatives based on a new scaffold - Polymer-bound cyclic malonic acid ester
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An efficient method for the preparation of polymer-bound cyclic malonic acid ester starting from Merrifield resin has been developed. Reaction of the resin-bound cyclic malonic acid ester with triethyl orthoformate and subsequent double substitution with
- Huang, Xian,Liu, Zhanxiang
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p. 6731 - 6737
(2007/10/03)
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- Preparation of a resin-bound cyclic malonic ester and a facile solid-phase synthesis of 4(1H)quinolones
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A resin-bound cyclic malonic ester has been prepared on Merrifield resin. Reaction of the cyclic malonic ester with triethyl orthoformate and subsequent substitution by an arylamine afforded arylaminomethylene cyclic malonic ester preloaded resin. A serie
- Huang, Xian,Liu, Zhanxiang
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p. 7655 - 7657
(2007/10/03)
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- Process for producing quinolone derivatives
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The present invention relates to a process for producing a 4-quinolone derivative, comprising allowing an o-aminoacetophenone derivative to react with a formic acid in an aprotic solvent in the presence of a suitable base, and adding a protic solvent to the reaction mixture. This is a simple process for producing 4-quinolone derivatives, applicable to large-scale commercial production.
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- SYNTHESIS OF 4(1H)-QUINOLONES BY THERMOLYSIS OF ARYLAMINOMETHYLENE MELDRUM'S ACID DERIVATIVES
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A series of 4(1H)-quinolones were obtained from Meldrum's acid and arylamines in two steps.
- Cassis, Raul,Tapia, Ricardo,Valderrama, Jaime A.
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p. 125 - 134
(2007/10/02)
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