17392-16-4Relevant academic research and scientific papers
Oxazole compound for hospital nursing sterilization and disinfection as well as preparation method and application of oxazole compound
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Paragraph 0021-0026, (2021/06/06)
The invention discloses an oxazole compound for hospital nursing sterilization and disinfection and a preparation method and application thereof, and belongs to the technical field of antibacterial drug synthesis. According to the key point of the technic
Silver-catalyzed Double Decarboxylative Radical Alkynylation/Annulation of Arylpropiolic Acids with α-keto Acids: Access to Ynones and Flavones under Mild Conditions
Meng, Mengting,Wang, Guofang,Yang, Liangfeng,Cheng, Kai,Qi, Chenze
supporting information, p. 1218 - 1231 (2018/02/16)
Ynones are privileged building blocks in various organic syntheses of heterocyclic derivatives due to their multifunctional nature, and flavones are an important class of natural products with a wide range of biological activities. We describe the catalytic double decarboxylative alkynylation of arylpropiolic acids with α-keto acids. With Ag(I)/persulfate as the catalysis system, the valuable ynones bearing various substituents could be easily obtained. The introduction of hydroxyl substituent on ortho-site of α-keto acids make this strategy further applicable to the construction of flavone derivatives via heteroannulation in moderate to good yields with a similar silver-catalyzed system. The reactions proceed under relatively mild reaction conditions and tolerate a wide variety of functional groups. Control experiments indicated that both the reactions undergo radical processes. (Figure presented.).
Asymmetric construction of spirocyclopentenebenzofuranone core structures via highly selective phosphine-catalyzed [3 + 2] cycloaddition reactions
Albertshofer, Klaus,Tan, Bin,Barbas III, Carlos F.
supporting information, p. 2958 - 2961 (2013/07/26)
An efficient organocatalytic asymmetric [3 + 2] cycloaddition reaction between 3-substituted methylenebenzofuranone derivatives and diverse Morita-Baylis-Hillman carbonates to provide complex polysubstituted spirocyclopentenebenzofuranone scaffolds in a single step is reported. C2-symmetric phospholanes were efficient nucleophilic catalysts of this transformation under mild conditions, providing reaction products comprised of three consecutive stereocenters, including one all-carbon center, with excellent enantioselectivity.
Kinetics and mechanism of hydrolysis of 3-diazobenzofuran-2-one and its hydrolysis product (3-hydroxybenzofuran-2-one)
Chiang,Kresge,Meng
, p. 82 - 88 (2007/10/03)
Rates of acid-catalyzed hydrolysis of 3-diazobenzofuran-2-one, measured in concentrated aqueous perchloric acid and hydrochloric acid solutions, were found to correlate well with the Cox-Yates Xo excess acidity function, giving kH+ = 1.66 × 10-4 M-1 s-1, m? = 0.86 and kH+/kD+ = 2.04. The normal direction (kH/kD > 1) of this isotope effect indicates that hydrolysis occurs by rate-determining protonation of the substrate on its diazo-carbon atom. It was found previously that the next higher homolog of the present substrate, 4-diazoisochroman-3-one, also undergoes hydrolysis by this reaction mechanism but with a rate constant 15 times greater than that for the present substrate; this difference in reactivity can be understood in terms of the various resonance forms that contribute to the structures of these substrates. The product of the present hydrolysis reaction is 3-hydroxybenzofuran-2-one, which itself quickly undergoes subsequent acid-catalyzed hydrolysis to 2-hydroxymandelic acid. The acidity dependence of this subsequent hydrolysis is much shallower than that of the diazo compound precursor, and rates of reaction correlate as well with [H+] as with Xo. This is due in part to incursion of a nonproductive protonation on the hydroxy group of 3-hydroxybenzofuran-2-one that impedes hydrolysis and produces saturation of acid catalysis. Rates of hydrolysis of the hydroxy compound were also measured in dilute HClO4 and NaOH solutions as well as in CH3CO2H, H2PO4-, (CH2OH)3CNH3-, and NH4- buffers, and the rate profile constructed from these data showed the presence of uncatalyzed and hydroxide ion-catalyzed reactions. This hydroxide-ion catalysis became saturated at [NaOH] ? 0.05 M, implying occurrence of yet another nonproductive substrate ionization.
Dye-sensitized Photo-oxygenation of Chalcones
Chawla, H. Mohindra,Chakrabarty, Kakoli
, p. 1511 - 1513 (2007/10/02)
The dye-sensitized photo-oxygenation of several chalcones has been examined.Some of the chalcones give rise to degradation products while others lead to flavonol formation.A rational explanation for the observations has been proposed.The study may have a significance in the biogenesis of naturally occurring plant polyphenolics.
Unusual Friedel-Crafts Reactions. Part 8. Synthesis of 2-Hydroxyarylglyoxylic Acids via ortho-Specific Oxaloylation of Phenols with Oxalyl Chloride
Bigi, Franca,Casiraghi, Giovanni,Casnati, Giuseppe,Sartori, Giovanni
, p. 2655 - 2657 (2007/10/02)
2-Hydroxyarylglyoxylic acids (6) are readily prepared from the bromomagnesium salts of phenols (2) and oxalyl chloride (3) in toluene at room temperature.This procedure bypasses some of the inherent difficulties in the conventional Friedel-Crafts acylatio
