Synthesis of Substituted Stilbenes via the Knoevenagel Condensation
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چکیده
منابع مشابه
Synthesis of substituted stilbenes via the Knoevenagel condensation.
Knoevenagel condensations between aldehydes and substrates containing active methylene groups were carried out in ethanol at room temperature, in the presence of potassium phosphate, to afford unsymmetrical olefins. These condensations have been shown to afford only the E-isomers in greater than 80% yields. Salicylaldehyde first produces the Knoevenagel condensation products, which undergo a su...
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1-Butyl-3-methylimidazolium chloroaluminate, [bmim]Cl·AlCl3, N=0.67 and 1-butylpyridinium chloroaluminate, [bpy]Cl·AlCl3, N=0.67 ionic liquids were found to work well as the Lewis acid catalyst and solvent in the Knoevenagel condensations of benzaldehyde and substituted benzaldehydes with diethyl malonate to give benzylidene malonates. The benzylidene malonates subsequently underwent Michael ad...
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The total synthesis and structure determination of cis- and trans-flocoumafen was described. The key synthetic steps involve Knoevenagel condensation with p-methoxybenzaldehyde, in situ decarboxylation and intramolecular ring cyclization to construct the tetralone skeleton. Stereospecific reduction of the O-alkylated ketone 13 afforded good yield of precusor alcohol 5. Final coupling of alcohol...
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An efficient construction of 2-(N-arylamino)benzaldehydes and N-aryl-3,10-dihydroacridin-1(2H)-one derivatives starting from 2- hydroxybenzaldehydes has been developed. The synthesis of N-aryl-3,10-dihydroacridin-1(2H)-ones is based on the Knoevenagel condensation of dimedone to various 2-(N-arylamino)benzaldehydes, followed by an intramolecular enamination in the presence of 20 mol% of nanocry...
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The mechanochemical Knoevenagel condensation of malononitrile with p-nitrobenzaldehyde was studied in situ using a tandem approach. X-ray diffraction and Raman spectroscopy were combined to yield time-resolved information on the milling process. Under solvent-free conditions, the reaction leads to a quantitative conversion to p-nitrobenzylidenemalononitrile within 50 minutes. The in situ data i...
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ژورنال
عنوان ژورنال: Molecules
سال: 2004
ISSN: 1420-3049
DOI: 10.3390/90800658