Ethylene glycol as hydrogen donor for the syntheses of thymol analogues via hydrolysis of 4-methylcoumarins
摘要:
Treatment of 4-methylcoumarins with potassium hydroxide in ethylene glycol resulted in the formation of the 'normal' 2-isopropenylphenols and/or the 'abnormal' 2-isopropylphenols depending on the nature of the substrates. The solvent ethylene glycol was believed to be the hydrogen donor for double-bonding reduction where 2-isopropylphenol was produced. (C) 2012 Elsevier Ltd. All rights reserved.
Rh-Catalyzed Synthesis of Coumarin Derivatives from Phenolic Acetates and Acrylates <i>via</i> C–H Bond Activation
作者:Sunita K. Gadakh、Soumen Dey、Arumugam Sudalai
DOI:10.1021/acs.joc.5b01713
日期:2015.11.20
An efficient annulation strategy involving the reaction of phenolic acetates with acrylates in the presence of [Rh2(OAc)4] as catalyst and formic acid as reducing agent, leading to the high yield synthesis of coumarin derivatives, has been developed. The addition of NaOAc as a base increased the yield of the products. The reaction is quite successful for both electron-rich as well as electron-deficient
Synthesis of Coumarins and Neoflavones through Zinc Chloride Catalyzed Hydroarylation of Acetylenic Esters with Phenols
作者:Paulo Costa、Raquel Leão、Paula de F. de Moraes、Marcella Pedro
DOI:10.1055/s-0031-1289576
日期:2011.11
Acetylenic esters react with oxygenated phenols under solvent-free conditions in the presence of only 5 mol% of zincchloride as a catalyst to give coumarins and neoflavones in reasonable-to-good yields. phenols - catalysis - arylations - heterocycles - alkynes - esters
A series of psoralens and structurally related 5,7-disubstituted coumarins was synthesized and investigated for their K+ channel blocking activity as well as for their phototoxicity to Artemia salina and their ability to generate singlet oxygen and to photomodify DNA. After screening the compounds on Ranvier nodes of the toad Xenopus Laevis, the affinities of the most promising compounds, which proved to be psoralens bearing alkoxy substituents in the 5-position or alkoxymethyl substituents in the neighboring 4- or 4'-position, to a number of homomeric K+ channels were characterized. All compounds exhibited the highest affinity to Kv1.2. 5,8-Diethoxypsoralen (10d) was found to be an equally potent inhibitor of Kv1.2 and Kv1.3, while lacking the phototoxicity normally inherent in psoralens. The reported compounds represent a novel series of nonpeptide blockers of Shaker-type K+ channels that could be further developed into selective inhibitors of Kv1.2 or Kv1.3.
[EN] COMPOSITION CONTAINING SEMICONDUCTOR NANOPARTICLES, COLOR FILTER, AND IMAGE DISPLAY DEVICE<br/>[FR] COMPOSITION CONTENANT DES NANOPARTICULES SEMI-CONDUCTRICES, FILTRE COLORÉ ET DISPOSITIF D'AFFICHAGE D'IMAGE<br/>[JA] 半導体ナノ粒子含有組成物、カラーフィルタ、及び画像表示装置