- The remarkable catalytic activity of ultra-small free-CeO2 nanoparticles in selective carbon-carbon bond formation reactions in water at room temperature
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A simple and efficient protocol for selective bis-Michael addition and mono-allylation of active methylene compounds has been demonstrated using ultra-small (size ~5 nm) uncapped cerium oxide nanoparticles (free-CeO2 NPs) as a reusable catalyst in water at room temperature. The free-CeO2 NPs were characterized by powder XRD, TEM and XPS studies. Free-CeO2 NPs efficiently catalyzed both the reactions and produced good to excellent yields of products.
- Banerjee, Subhash
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supporting information
p. 5350 - 5353
(2015/07/07)
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- A simple, efficient and green procedure for Michael addition catalyzed by [C4dabco]OH ionic liquid
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A dabco-based basic ionic liquid, 1-butyl-4-aza-1-azaniabicyclo[2.2.2] octane hydroxide, has been developed as a catalyst for a convenient and rapid method for the Michael addition of active methylene compounds to α,β-unsaturated carboxylic esters and nitriles. The method is very simple, and the yields are very high. The catalyst can be recycled several times without much loss of activity.
- Keithellakpam, Sanjoy,Laitonjam, Warjeet S.
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p. 767 - 770
(2014/06/09)
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- Superbasic sodium stannate as catalyst for dehydrogenation, Michael addition and transesterification reactions
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It has been shown that sodium stannate with superbasic sites generated on its surface can be obtained through simple thermal treatment of sodium stannate hydrate in pure N2. In this study, we analyzed the as-prepared materials using powder X-ray diffraction, X-ray photoelectron spectroscopy, and N2 physisorption methods. The superbasic sites were characterized by techniques of Hammett indicators and temperature-programmed desorption using CO2 as adsorbate. It was shown that after undergoing calcination at 623 K, there are ample superbasic sites on sodium stannate: up to 0.254 mmol/g. The superbasicity of the materials was further confirmed by employing the 1-hexene as well as cyclohexa-1,4-diene double bond isomerization reactions. The superbasicity is attributed to the higher electron-donating ability of surface O2-. The sodium stannate samples showed excellent catalytic efficiency towards selected reactions, namely the dehydrogenation of propa-2-nol, Michael addition of electron-deficient olefins, and transesterification of cyclic carbonate with methanol. It was observed that with rise of heat-treatment temperature from 573 to 623 K, both superbasicity and catalytic activity increased, reaching a maximum at 623 K, and then declined. It is deduced that catalytic efficiency is closely related to superbasicity of the sodium stannate catalysts.
- Zhang, Shu-Guo,Wei, Yu-Dan,Yin, Shuang-Feng,Luo, Sheng-Lian,Au, Chak-Tong
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experimental part
p. 113 - 118
(2012/03/09)
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- Remarkable catalytic activity of silica nanoparticle in the bis-Michael addition of active methylene compounds to conjugated alkenes
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We have demonstrated the remarkable catalytic activity of silica nanoparticles (NPs) in the unusual bis-Michael addition of active methylene compounds to conjugated alkenes at room temperature. The catalyst silica NPs were reused up to seven runs without appreciable loss of catalytic activity.
- Banerjee, Subhash,Santra, Swadeshmukul
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experimental part
p. 2037 - 2040
(2009/09/05)
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- STABILIZATION OF HYDROXYLAMINE CONTAINING SOLUTIONS AND METHOD FOR THEIR PREPARATION
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The invention relates to the use of amidoximes for prevention of or stabilization of hydroxylamine compounds against undesired decomposition.
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Page/Page column 18
(2009/05/28)
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- Ionic liquid as catalyst and solvent: the remarkable effect of a basic ionic liquid, [bmIm]OH on Michael addition and alkylation of active methylene compounds
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A basic ionic liquid, 1-methyl-3-butylimidazolium hydroxide, [bmIm]OH, catalyzes the Michael addition of active methylene compounds to conjugated ketones, carboxylic esters and nitriles. It further catalyzes the addition of thiols to α,β-acetylenic ketones and alkylation of 1,3-dicarbonyl and -dicyano compounds. The Michael addition to α,β-unsaturated ketones proceeds in the usual way, giving the monoaddition products, whereas addition to α,β-unsaturated esters and nitriles leads exclusively to the bis-addition products. The α,β-acetylenic ketones undergo double conjugate addition with thiols producing β-keto 1,3-dithio-derivatives. In the alkylation reaction the acyclic 1,3-diketones are monoalkylated, whereas cyclic ketones undergo dialkylation under identical conditions. All these reactions were carried out without any organic solvent. The ionic liquid can also be recycled.
- Ranu, Brindaban C.,Banerjee, Subhash,Jana, Ranjan
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p. 776 - 782
(2007/10/03)
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- The Reaction of Phenacyl malononitrile with Hydrazines: Synthesis of New Pyridazinones and PyrazoloPyrimidines
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The reaction of phenacylmalonitrile with hydrazine hydrate affords a mixture of 3,5-diamino-4-phenacylpyrazole, 2, and 6-oxo-3-phenyl-1,4,5,6-tetrahydropyridazine-5-carbonitrile, 5.The reaction of 2 with a variety of reagents, that enabled the synthesis o
- Elnagdi, Mohamed Hilmy,El-Ghamry, Ibrahim,Kandeel, Ezz,Rahman, A. H. Abdel,Al-Naggar, Abdul Aziz,et al.
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p. 791 - 794
(2007/10/03)
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- Dispiromacrocycles: A class of diamide and diimide ionophores
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A series of novel ionophores was synthesized in three steps from acrylonitrile and diethyl malonate or malononitrile via 2,8-diazaspiro[5,5]undecane-1,7-dione (7) or 2,8-diazaspiro[5,5]undecane-1,3,7,9-tetrone (8). Spirodiamide macrocycle 14 imparts selec
- Bell,Choi,Hiel
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p. 971 - 974
(2007/10/02)
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- UTILISATION DE MEMBRANES ECHANGEUSES D'IONS EN ELECTROSYNTHESE ORGANIQUE.
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The addition of carbon acids to acrylonitrile or methyl acrylate can be initiated by means of bases electrogenerated in aprotic media in the absence of supporting-electrolyte, at the interface between a porous cathode and a solid polymer electrolyte.The consumption of electricity is below 1E-2 faraday per mole.Putting to the test donors with decreasing acidity (2-nitropropane, malononitrile, diethyl malonate, ethyl cyanacetate, 2-methylcyclohexanone, fluorene) allows to estimate the basicity level that can be reached at such an interface.The influence of differentfactors (such as the nature of the ion exchange membrane, the basicity of the second side of the membrane, the presence of a probase) on the rates and yields of the reactions has been investigated.
- Raoult, Eugene,Sarrazin, Jean,Tallec, Andre
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p. 5299 - 5306
(2007/10/02)
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- Michael Additions Catalyzed by Metal(II) Complexes
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Michael-addition reactions have been found to proceed in the presence of the Ni(OAc)2 or Co(OAc)2-2,2'-bypiridine complex in DMF under neutral conditions at room temperature without any by-product.The reactions of chalcone and its derivatives with nitromethane generally gave good results.The effects of metal(II) ions, ligands, counter ions, and solvents on the catalysis were examined, and the features of the metal-complex-catalyzed Michael reactions were studied, with some considerations also being given to the catalysis mechanism.
- Watanabe, Ken-ichi,Miyazu, Ken-ichi,Irie, Kazuro
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p. 3212 - 3215
(2007/10/02)
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- MICHAEL ADDITIONS CATALYZED BY NICKEL(II) OR COBALT(II)ACETATE-2,2'-BIPYRIDINE COMPLEXES
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In the presence of nickel(II) or cobalt(II)acetate-2,2'-bipyridine complexes, α,β-unsaturated ketones, methyl acrylate, and acrylonitrile were found to react with nitromethane, malononitrile, and aniline at room temperature under neutral condition to afford addition products in good yields.
- Irie, Kazuo,Miyazu, Ken-ichi,Watanabe, Ken-ichi
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p. 353 - 354
(2007/10/02)
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