نتایج جستجو برای: β-diketones
تعداد نتایج: 177869 فیلتر نتایج به سال:
phenylazo and benzothiazolylazo derivatives of trifluoroacetylacetone andhexafluoroacetylacetone have been synthesized and characterized. analytical and spectral datarevealed the existence of phenylazo derivatives in the intramolecularly hydrogen-bonded ketohydrazoneform while the benzothiazolylazo derivatives in the azo-enol form. the monobasicbidentate coordination of the phenylazo derivative...
Four new 1,5-benzothiazepines were synthesized by reaction of o-aminothiophenol with curcumin and curcuminoid β-diketones, in methanol acetic acid. The mechanism involves a Michael addition on the CC double bond affording benzothiazepine two pendant groups, an aryl group adjacent to sulfur atom 1-phenylethanone NH seven membered ring. 1D 2D multinuclear NMR (1H, 13C, 15N, 119F) solution 13C 15N...
The glossy varieties (A14 and Jing 2001) and glaucous varieties (Fanmai 5 and Shanken 99) of wheat (Triticum aestivum L.) were selected for evaluation of developmental changes in the composition and morphology of cuticular waxes on leaves and spikes. The results provide us with two different wax development patterns between leaf and spike. The general accumulation trend of the total wax load on...
Thiazolium carbene-catalyzed reactions of 1,2-diketones and 1,2,3-triketones with enones and ynones have been investigated. The diketones gave α,β-double acylation products via unique Breslow intermediates isolable as acid salts, whereas the triketones formed stable adducts with the NHC instead of the coupling products.
BACKGROUND Ferrocene-containing β-diketones and cisplatin, [(NH(3))(2)PtCl(2)], possess strong antineoplastic activity. No information is available regarding the anticancer activity of the corresponding ruthenocene complexes. This study examined the cytotoxicity of stable ruthenocene-containing β-diketones. The results were related to the cytotoxicity of cisplatin and the ease of ruthenium elec...
An enzymatic strategy for the preparation of optically pure α-alkyl-α,β-dihydroxyketones is reported. Homo- and cross-coupling reactions of α-diketones catalyzed by acetylacetoin synthase (AAS) produce a set of α-alkyl-α-hydroxy-β-diketones (30-60%, ee 67-90%), which in turn are reduced regio-, diastereo-, and enantioselectively to the corresponding chiral α-alkyl-α,β-dihydroxyketones (60-70%, ...
A low cost, safe, clean and environmentally benign base-catalyzed cyclodehydration of appropriate β-diketones affording (E)-2-styrylchromones and flavones in good yields is disclosed. Water was used as solvent and the reactions were heated using classical and microwave heating methods, under open and closed vessel conditions. β-Diketones having electron-donating and withdrawing substituents wer...
The use of sonochemistry is described in the organocatalytic enamine-azide [3 + 2] cycloaddition between 1,3-diketones and aryl azidophenyl selenides. These sonochemically promoted reactions were found to be amenable to a range of 1,3-diketones or aryl azidophenyl selenides, providing an efficient access to new ((arylselanyl)phenyl-1H-1,2,3-triazol-4-yl)ketones in good to excellent yields and s...
condensation of aromatic aldehydes with benzoyl acetone under specified conditions yieldedtwo series of polycarbonyl compounds in which the keto group is attached to olefinic linkage.spectral and analytical data revealed the formation of an unsaturated triketone from pyridine-3-carbaldehyde and unsaturated diketone from furfural, salicylaldehyde and 2-hydroxynaphthaldehyde. analytical, ir, 1h n...
The oxidation of β-hydroxyketones to β-diketones was systematically investigated. o-Iodoxybenzoic acid (IBX) was found to be efficient, operationally easy, and superior to other common oxidants. The reaction is suitable for milligram- to gram-scale oxidations.
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید