Synthese des 3‐Oxyflavons

Emilewicz, T.; Kostanecki, v.

doi:10.1002/cber.189803101147

Cited by 48 publications

(4 citation statements)

References 8 publications

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“…Their biochemical role is unclear, but it has been suggested to be that of a natural fungicide . They can be synthesized by cyclization of dibromo chalcones , or β-diketones, , or by the oxidation of flavanones with selenium dioxide 23 or their dehydrogenation using palladium in n -octadecanol . Previous synthesis of 6-oxopyrroloquinolines was effected by the acid-catalyzed cyclization of indole β-diketones .…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Pyrroloquinolines as Indole Analogues of Flavonols

2002

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7-Acetyl-4,6-dimethoxy-3-phenylindole 10 was converted into a range of 7-indolyl chalcones 13 by reaction with aryl aldehydes under basic conditions. Oxidation of the chalcones 13 with alkaline hydrogen peroxide gave the isolable epoxides 14, which were cyclized with further base treatment into the indole flavonols, or 5-hydroxy-6-oxopyrroloquinolines 15. The related compounds 25 and 26, examples of indole flavanones and flavones, respectively, were also synthesized. UV spectroscopic comparisons between flavonoids and indole flavonoids are discussed.

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Section: Resultsmentioning

confidence: 99%

Synthesis of Pyrroloquinolines as Indole Analogues of Flavonols

2002

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“…The most convenient method for the preparation of our target flavone derivatives is by a direct conversion of the 2‘-hydroxychalcones which we have synthesized previously . Methods available for this conversion involve either dehydrohalogenation − or ring closure under the influence of oxidants such as SeO 2 − or 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). , …”

Section: Chemistrymentioning

confidence: 99%

Synthesis and Structure−Activity Relationships of Carboxyflavones as Structurally Rigid CysLT₁ (LTD₄) Receptor Antagonists

et al. 1998

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The synthesis and CysLT1 receptor affinities of a new series of highly rigid 3'- and 4'-(2-quinolinylmethoxy)- or 3'- and 4'-[2-(2-quinolinyl)ethenyl]-substituted, 6-, 7-, or 8-carboxylated flavones are described. CysLT1 receptor affinities of the flavones (down to 11 nM) were determined by their ability to displace [3H]LTD4 from its receptor in guinea pig lung membranes. Structure-affinity relationship studies showed that the relative positions of the carboxylic acid and the quinoline moiety were critical for CysLT1 affinities. While the carboxyl is optimal in the 8 position but tolerated in the 6 position, only the 6- and not the 8-tetrazole has significant activity. The quinoline moiety may be connected to the flavone skeleton by an ethenyl or a methoxy linker, but the substitution position is important for high affinity, especially in the 6-carboxylated flavones. 4'-Substituted 6-carboxyflavones are essentially inactive, whereas the 3'-substituted analogues have submicromolar CysLT1 affinity. Replacement of the quinoline by other heteroaromates generally leads to decreased affinities, with the phenyl and naphthyl analogues displaying only little or no affinity, while the 7-chloroquinoline analogue is comparable in activity to the quinoline. Flavones having CysLT1 receptor affinities of 10-30 nM were selected for determination of their inhibitory effects on the LTD4-induced contraction of guinea pig ileum in vitro. The IC50 values ranged between 15 and 100 nM. Compound 5d (8-carboxy-6-chloro-3'-(2-quinolinylmethoxy)flavone, VUF 5087) was selected for further research because of its high potency in the functional assay. This series contains the most rigid CysLT1 receptor antagonists known to date, and they are useful in the development of a CysLT1 antagonist model, which is discussed in the companion paper.

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“…The compounds bearing flavone skeletons are wide spread in Nature and found broad spectrum of applications in medicinal, material and synthetic chemistry 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 . For instance, the flavone compounds displayed antiulcer, anticancer, antitumor, antinociceptive, anti-inflammatory, antioxidant, antimicrobial, antiviral, antidiabetic and many other pharmacological properties 30 31 32 33 34 35 36 37 .…”

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confidence: 99%

“…For instance, the flavone compounds displayed antiulcer, anticancer, antitumor, antinociceptive, anti-inflammatory, antioxidant, antimicrobial, antiviral, antidiabetic and many other pharmacological properties 30 31 32 33 34 35 36 37 . Tremendous application of flavone compounds has grown interest among the scientists for their synthesis even in 1898 38 . Intramolecular cyclization of 2-hydroxychalcones, oxidative cyclization of acetophenone, dehydrative cyclization of 1,3-diaryl diketones, cyclization of alkynones, carbon monoxide insertion of iodophenols with terminal alkynes, cycloaddition of α-oxoketene and benzyne, and multistep strategies were developed for their synthesis 39 40 41 42 43 44 45 .…”

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Functionalised MnVI-nanoparticles: an advanced high-valent magnetic catalyst

Khamarui

Saima

Laha

et al. 2015

Sci Rep

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We discover MnVI-nanoparticles (NPs) bearing functional groups, high oxidation state, strong electron affinity, unique redox and paramagnetic nature, which opens up a new avenue to catalysis, magnetism and material application. However, its synthesis is challenging and remains unexplored because of associated serious difficulties. A simple benign synthetic strategy is devised to fabricate the high-valent NPs using mild reducing agent bromide, which transformed MnVII to valuable MnVI-species. The EELS-imaging of individual elements, ESI-MS, XPS and other techniques established its composition as Br(Me3SiO)MnVIO2. It revealed significantly improved magnetic moment (SQUID) with isotropic hyperfine splitting of six line spectrum (EPR). The high-oxidation state and incorporated-ligands of the metals present on the active surface of the NPs led to development of a general catalytic process for oxidative heterodifunctionalisation to C-C triple bond towards formation of a new O-C/N-C/S-C and C-C coupling cum cyclisation to biologically important flavones and their aza- and marcapto-analogues, and valuable enaloxy synthons.

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Synthese des 3‐Oxyflavons

Cited by 48 publications

References 8 publications

Synthesis of Pyrroloquinolines as Indole Analogues of Flavonols

Synthesis of Pyrroloquinolines as Indole Analogues of Flavonols

Synthesis and Structure−Activity Relationships of Carboxyflavones as Structurally Rigid CysLT₁ (LTD₄) Receptor Antagonists

Functionalised MnVI-nanoparticles: an advanced high-valent magnetic catalyst

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Synthese des 3‐Oxyflavons

Cited by 48 publications

References 8 publications

Synthesis of Pyrroloquinolines as Indole Analogues of Flavonols

Synthesis of Pyrroloquinolines as Indole Analogues of Flavonols

Synthesis and Structure−Activity Relationships of Carboxyflavones as Structurally Rigid CysLT1 (LTD4) Receptor Antagonists

Functionalised MnVI-nanoparticles: an advanced high-valent magnetic catalyst

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Synthesis and Structure−Activity Relationships of Carboxyflavones as Structurally Rigid CysLT₁ (LTD₄) Receptor Antagonists