- Water-mediated phosphorylative cyclodehydrogenation: An efficient preparation of flavones and flavanones
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A new synthetic strategy utilizing POCl3-water for the conversion of 2′-hydroxychalcones to flavanones and flavones has been developed. The reagent efficiently promoted one-pot conversion of 2′-hydroxychalcones to flavones through flavanones involving cyclization and oxidative dehydrogenation. By changing the stoichiometery of the reagents, the reaction can be tuned to generate either flavanone or flavone. The developed protocol was found to be applicable for a variety of 2′-hydroxychalcones.
- Vimal, Manorama,Pathak, Uma,Halve, Anand Kumar
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supporting information
p. 2805 - 2814
(2019/08/12)
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- Method for synthesizing flavonoids compound in one step by virtue of catalysis of 1,3-dialkylimidazolium oxometallate
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The invention discloses a method for synthesizing a flavonoids compound in one step by virtue of catalysis of 1,3-dialkylimidazolium oxometallate. The method is characterized by comprising the following steps: sequentially adding raw material benzaldehyde or benzaldehyde derivatives, raw material 2-hydroxyacetophenone or 2-hydroxyacetophenone derivatives, an ion liquid catalyst and an organic solvent into a reactor, stirring, heating to 50 to 90 DEG C, reacting for 2 to 7 hours at a constant temperature by taking oxygen or air as an oxidant, cooling, distilling under reduced pressure, carrying out the column chromatography, and re-crystallizing and separating to obtain the target product flavonoids compound. The method has the characteristics that the ion liquid is used as the catalyst, the yield of the flavonoids compound synthesized in one step reaches 85 percent or more, therefore, compared with the traditional synthetic method, the reaction flow is shortened, and the synthetic efficiency of the flavonoids compound is remarkably improved. The method has advantages of high product yield, low production cost, simple operation procedures, moderate reaction conditions and the like and is proved to be a novel method for high-efficiently synthesizing the flavonoids compound.
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Paragraph 0065; 0066; 0067
(2016/10/08)
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- Ionic liquid mediated Cu-catalyzed cascade oxa-Michael-oxidation: Efficient synthesis of flavones under mild reaction conditions
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Flavonoids are a class of natural products, found in a wide range of vascular plants and dietary components. Their low toxicity and extensive biological activities, including anti-cancer and anti-bacterial, have made them attractive candidates to serve as therapeutic agents for many diseases. Herein, we disclose a highly efficient synthetic method of CuI-catalyzed cascade oxa-Michael-oxidation, using chalcones as substrates, mediated by the ionic liquid [bmim][NTf2] at a low temperature. This efficient synthetic method has demonstrated high synthetic utility and can afford flavones in good to high yields (up to 98%).
- Du, Zhiyun,Ng, Huifen,Zhang, Kun,Zeng, Huaqiang,Wang, Jian
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p. 6930 - 6933
(2011/11/04)
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- Transcription factor modulating compounds and methods of use thereof
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Substituted benzoimidazole compounds useful as anti-infectives that decrease resistance, virulence, or growth of microbes are provided. Methods of making and using substituted benzoimidazole compounds, as well as pharmaceutical preparations thereof, in, e.g., reducing antibiotic resistance and inhibiting biofilms.
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Page/Page column 74
(2008/06/13)
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- Transcription factor modulating compounds and methods of use thereof
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Substituted benzoimidazole compounds useful as anti-infectives that decrease resistance, virulence, or growth of microbes are provided. Methods of making and using substituted benzoimidazole compounds, as well as pharmaceutical preparations thereof, in, e.g., reducing antibiotic resistance and inhibiting biofilms.
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- REACTIONS OF 3-ARYL-1--2-PROPYN-1-ONES IN THE PRESENCE OF AMINES. TWO TYPES OF INTRAMOLECULAR CYCLIZATION INVOLVING THE ortho-HYDROXYL GROUP
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Amines react with 3-aryl-1--2-propyn-1-ones in three directions, i.e., with addition of the reagent at the triple bond (and the formation of the β-aminovinyl ketone) and intramolecular cyclization leading to the formation of six-membered (flavones) or five-membered (aurones) heterocycles.The development of these reaction paths is controlled by the nature of the amines.Probable reaction paths are proposed.
- Korshunov, S. P.,Korzhova, N. V.,Kazantseva, V. M.,Krasnov, V. L.,Utekhina, N. V.,Bodrikov, I. V.
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p. 1658 - 1663
(2007/10/02)
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- FLAVONOIDS, 39. THE REACTION OF 3-MESYLOXYFLAVANONES WITH O- AND S-NUCLEOPHILES, SYNTHESIS OF 3-THIOCYANATO- AND 3-ACETYLTHIO-FLAVANONES
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The action of either cyanate or acetate ions on trans-3-mesyloxyflavanones 1 led to the formation of flavones 2 and aurones while the reaction with the respective S-nucleophiles (thiocyanate and thioacetate ions) resulted in cis- and trans-3-thiocyanato- and 3-acetylthioflavanones (6 and 11).The participation of the concurrent nucleophilic substitution, β-elimination and elimination with ring-contraction is dependent on the "hard-soft" character of the nucleophile and the increase of the "soft" character favours the displacement.
- Patonay, Tamas,Litkei, Gyoergy,Bognar, Rezsoe
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p. 3425 - 3430
(2007/10/02)
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