نتایج جستجو برای: β–unsaturated ketones moieties

تعداد نتایج: 19705  

2010
Daniela Rossi Anna Carnevale Baraglia Massimo Serra Ornella Azzolina

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.

2009
Chuan-Ji Yu

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.

2013
Ashok P. Acharya Rahul D. Kamble Snehalkumar D. Patil Shrikant V. Hese Bhaskar S. Dawane

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...

2015
FATEMEH ABDOLLAHPOUR

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...

Journal: :journal of agricultural science and technology 2014
j. guo h. wu l. du w. zhang j. yang

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...

2012
Georg Süss-Fink Christian Bruneau

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...

Journal: :Organic letters 2000
Nicolaou Vassilikogiannakis Kranich Baran Zhong Natarajan

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...

Journal: :Chemical & pharmaceutical bulletin 2013
Kenzo Yahata Masaki Minami Yuki Yoshikawa Kei Watanabe Hiromichi Fujioka

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...

Journal: :Organic letters 2002
Jose L Vicario Andreas Job Michael Wolberg Michael Müller Dieter Enders

[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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