نتایج جستجو برای: β–unsaturated ketones moieties
تعداد نتایج: 19705 فیلتر نتایج به سال:
A microwave-assisted HWE olefination process of readily accessible aryl-alkyl ketones has been developed to provide a rapid access to (Z)-3,3-trisubstituted-α,βunsaturated methyl esters, key building blocks for the synthesis of biologically active compounds.
The Brønsted acid ionic liquid [PyN(CH2)4SO3H][p-CH3PhSO3] has been reported as an efficient catalyst for the Michael addition reaction of indoles to α,βunsaturated ketones. Satisfactory results were obtained, with excellent yields and a simple experimental procedure. The catalyst could be recycled and reused up to three times without any noticeable decrease in the catalytic activity.
In present communication a novel series of benzodiazepine derivatives were synthesized from α, β-unsaturated ketones and evaluated for their antimicrobial activities. The α, β-unsaturated ketones were prepared by ClaisenSchimidt Condensation of Indan-1-one with different aldehydes in presence bleaching earth clay and PEG400 as Greener reaction solvent. A novel benzodiazepine derivatives were sy...
(Caffeine) (tetrahydroborato)zinc Complex [Zn(BH4)2(caf)]: A New Stable and Efficient Reducing Agent
In this context, (Caffeine)(tetrahydroborato)zinc complex as white stable reducing agents [Zn(BH 4 ) 2 (caf)], has been prepared by complexation of one equimolar amounts of zinc tetrahydroborate and one equimolar amounts of caffeine at room temperature. Also, [Zn(BH 4 ) 2 (caf) ]has been used for reduce of a variety of carbonyl compounds such as aldehydes, ketones, α, βunsaturated carbonyl comp...
ginger (zingiber officinale roscoe) contains the biological properties of the major standard non–volatile pungent compounds of ginger, namely, [6]–, [8]–, and [10]–gingerols, as well as [6]– , [8]–, and [10]–shogaols. so far, the comparative antioxidant potencies among shogaols and gingerols have not been studied in detail and reported. accordingly, this study aimed to examine and compare the a...
Introduction: Bifunctional radiosensitizer agents in which nitroaromatic moieties are attached through a linker to antineoplastic moieties have demonstrated higher cytotoxicity and radiosensitizer effects than the corresponding counterparts. This study was conducted to investigate the cytotoxicity and radiosensitizer activities of 2, 4-dinitrobenzene as a radiosensitizer moiety...
Selective hydrogenation of the carbon-oxygen bond in α,β-unsaturated carbonyl compounds is a synthetic challenge, since C=C bond reduction is thermodynamically more favorable (35 kJ mol–1) than C=O bond reduction.[1] This problem becomes even more complicated by the presence of an aromatic substituent in such systems because of possible ring hydrogenation.[2] Moreover, the transformation of uns...
A selective, mild, and highly efficient method has been uncovered during the total synthesis of the CP molecules to accomplish the one-carbon homologation of sterically hindered aldehydes in the presence of acid- and base-labile moieties, Michael acceptors, and even other carbonyl groups such as reactive and epimerizable ketones. Mechanistic studies have revealed a neutral reagent for the rapid...
A methodology for selective transformations of ketones, esters, Weinreb amides, and nitriles in the presence of aldehydes has been developed. The use of a combination of PPh(3)-trimethylsilyl trifluoromethanesulfonate (TMSOTf) promotes selective transformation of aldehydes to their corresponding, temporarily protected, O,P-acetal type phosphonium salts. Because, hydrolytic work-up following ens...
[structure: see text] The asymmetric total synthesis of (-)-callystatin A has been achieved. The key steps generating the stereogenic centers rely on the asymmetric alpha-alkylation of aldehydes or ketones exploiting the SAMP/RAMP hydrazone alkylation methodology, as well as an enzymatic enantioselective reduction of a 3,5-dioxocarboxylate. For the construction of the alkene moieties, highly se...
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