نتایج جستجو برای: unsaturated compounds

تعداد نتایج: 241045  

2010
Natalija M. Krstić Mira S. Bjelaković Milan M. Dabović Vladimir D. Pavlović

The reactions of selected α,β-unsaturated steroidal ketones with Lawesson’s reagent (LR) in CH2Cl2 and toluene under the standard reaction conditions and with a combination of phosphorus pentasulfide with hexamethyldisiloxane (P4S10/HMDO) in 1,2dichlorobenzene (ODCB) under microwave irradiation were investigated and for this purpose several cholestane, androstane and pregnane carbonyl derivativ...

2008
Ursula Biermann Jürgen O. Metzger

Alkyl-branched fatty compounds are of interest for industrial products in the cosmetics and lubricant areas. In this review, clayand zeolite-catalyzed isomerizations of unsaturated fatty compounds, especially of oleic acid, are discussed. While clay-catalyzed reactions give most complex mixtures of dimeric fatty acids and of monomeric so-called “isostearic acid”, the zeolite-catalyzed process y...

Journal: :Molecules 2017
Yiming Xu Lichuan Wu Hang Dai Mingyan Gao Haroon Ur Rashid Haodong Wang Peng Xie Xu Liu Jun Jiang Lisheng Wang

Using sophoridine 1 and chalcone 3 as the lead compounds, a series of novel α, β-unsaturated sophoridinic derivatives were designed, synthesized, and evaluated for their in vitro cytotoxicity. Structure-activity relationship (SAR) analysis indicated that introduction of α, β-unsaturated ketone moiety and heterocyclic group might significantly enhance anticancer activity. Among the compounds, 2f...

Journal: :Organic & biomolecular chemistry 2015
J J Medvedev M V Meleshina T L Panikorovskii C Schneider V A Nikolaev

Thermal decomposition of a series of diazodicarbonyl compounds in the presence of α,β-unsaturated δ-amino esters and sodium hydride gives rise to a variety of nitrogenous heterocycles. The direction of these processes is highly dependent on the structure of the initial reagents giving rise to the formation of multi-functionalized 2-oxopiperidines, 5,6-dihydropyridin-2(1H)-ones or tetrahydroisoq...

Journal: :Organic & biomolecular chemistry 2013
Sabine Amslinger Nafisah Al-Rifai Katrin Winter Kilian Wörmann Rebekka Scholz Paul Baumeister Martin Wild

The electrophilic nature of chalcones (1,3-diphenylprop-2-en-1-ones) and many other α,β-unsaturated carbonyl compounds is crucial for their biological activity, which is often based on thiol-mediated regulation processes. To better predict their biological activity a simple screening assay for the assessment of the second-order rate constants (k(2)) in thia-Michael additions was developed. Henc...

Journal: :Accounts of chemical research 2015
Antonio C B Burtoloso Rafael M P Dias Barbara Bernardim

Among the different types of diazocarbonyl substrates found in the literature to date, α,β-unsaturated diazoketones have proven to be very promising as multifunctional intermediates. Possessing a diazo group, a ketone function and a double bond all together in a single molecule, these compounds constitute versatile building blocks for synthesis. For example, double bond functionalization, follo...

Journal: :iranian journal of catalysis 2014
tarlan salehi-hamzehkhani marzieh hatami abdolkarim zare ahmad reza moosavi-zare abolfath parhami

michael addition of pyrimidine and purine nucleobases to substituted as well as unsubstituted α,β-unsaturated esters efficiently proceeds in the presence of catalytic amount of zinc oxide in ionic liquid 1-butyl-3-methylimidazolium bromide (zno/[bmim]br) under microwave irradiation to afford carboacyclic nucleosides, as biologically important compounds, in good to excellent yields and in short ...

Journal: :Journal of the American Chemical Society 2015
Tingshun Zhu Chengli Mou Baosheng Li Marie Smetankova Bao-An Song Yonggui Robin Chi

An N-heterocyclic carbene (NHC) catalyzed domino reaction triggered by a δ-LUMO activation of α,β-γ,δ-diunsaturated enal has been developed for the formal [4 + 2] construction of multisubstituted arenes and 3-ylidenephthalide. These two products, formed in a highly chemo- and regioselective manner, were obtained via different catalytic pathways due to a simple change of the substrate. The activ...

2012
Oksana Sereda Nicole Clemens Tatjana Heckel René Wilhelm

The application of imidazolinium and amidinium salts as soft Lewis acid organocatalysts is described. These salts were suitable catalysts for the activation of unsaturated thioesters in a Diels-Alder reaction and in the ring opening of thiiranes and epoxides. The products were isolated in good yields. The mild catalysts did not cause desulfurization of the products containing a thiol or thiocar...

Journal: :The Journal of the Society of Chemical Industry, Japan 1967

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