- Conjugate Addition of Nitro-Derivatives to α,β-Unsaturated Carbonyl Compounds on Basic Alumina
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Conjugate addition of nitroalkanes to α,β-unsaturated carbonyl compounds occurs in the presence of basic alumina without a solvent.Yields are fair to good also with substrates which are acid or base sensitive.
- Rosini, Goffredo,Marotta, Emanuela,Ballini, Roberto,Petrini, Marino
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- Solvent-Free Henry and Michael Reactions with Nitroalkanes Promoted by Potassium Carbonate as a Versatile Heterogeneous Catalyst
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The use of a simple weak inorganic base such as potassium carbonate facilitated the formation of carbon-carbon bonds through both the Henry and the Michael reactions with nitrocompounds. The application of this catalyst under environmentally friendly solventless heterogeneous conditions gave satisfactory to good yields of β-nitroalcohols, involving aliphatic and aromatic starting materials, as well as high to excellent yields in the formation of Michael adducts using several different Michael acceptors and nitroalkanes.
- Bosica, Giovanna,Polidano, Kurt
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- Highly enantioselective conjugate addition of nitroalkanes to enones catalyzed by cinchona alkaloid derived primary amine
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A cinchona alkaloid derived primary amine catalyzed conjugate addition of nitroalkanes to enones is described. The process affords the Michael adducts in good yield and with up to 99% ee for both acyclic and cyclic enones.
- Liu, Wenjing,Mei, Desheng,Wang, Wei,Duan, Wenhu
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supporting information
p. 3791 - 3793
(2013/07/05)
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- Solvent-free Michael addition of 2-cyclohexenone under ultrasonic irradiation in the presence of long chain dicationic ammonium salts
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Long chain dicationic ammonium salts (1a-1c), easily prepared from tert-amines and dihaloalkanes, were successfully used as efficient phase-transfer catalysts in the Michael addition reaction of various active methylene compounds to 2-cyclohexenone withou
- Oge, Aytek,Mavis, Murat Emrah,Yolacan, Cigdem,Aydogan, Feray
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experimental part
p. 137 - 146
(2012/03/11)
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- Ionic liquids made with dimethyl carbonate: Solvents as well as boosted basic catalysts for the michael reaction
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This article describes 1) a methodology for the green synthesis of a class of methylammonium and methylphosphonium ionic liquids (ILs), 2) how to tune their acid-base properties by anion exchange, 3) complete neat-phase NMR spectroscopic characterisation
- Fabris, Massimo,Lucchini, Vittorio,Noe, Marco,Perosa, Alvise,Selva, Maurizio
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experimental part
p. 12273 - 12282
(2010/06/11)
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- Bifunctional heterogeneous catalysis of silica-alumina-supported tertiary amines with controlled acid-base interactions for efficient 1,4-addition reactions
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We report the first tunable bifunctional surface of silica-aluminasupported tertiary amines (SA-NEt2) active for catalytic 1,4-addition reactions of nitroalkanes and thiols to electron-deficient alkenes. The 1,4-addition reaction of nitroalkanes to electron-deficient alkenes is one of the most useful carbon-carbon bond-forming reactions and applicable toward a wide range of organic syntheses. The reaction between nitroethane and methyl vinyl ketone scarcely proceeded with either SA or homogeneous amines, and a mixture of SA and amines showed very low catalytic activity. In addition, undesirable side reactions occurred in the case of a strong base like sodium ethoxide employed as a catalytic reagent. Only the present SA-supported amine (SA-NEt2) catalyst enabled selective formation of a double-alkylated product without promotions of side reactions such as an intramolecular cyclization reaction. The heterogeneous SA-NEt2 catalyst was easily recovered from the reaction mixture by simple filtration and reusable with retention of its catalytic activity and selectivity. Fur-thermore, the SA-NEt2 catalyst system was applicable to the addition reaction of other nitroalkanes and thiols to various electron-deficient alkenes. The solid-state magic-angle spinning (MAS) NMR spectroscopic analyses, including variable-contact-time 13C cross-polarization (CP)/MAS NMR spectroscopy, revealed that acid-base interactions between surface acid sites and immobilized amines can be controlled by pretreatment of SA at different temperatures. The catalytic activities for these addition reactions were strongly affected by the surface acid-base interactions. 2009 Wiley-VCH Verlag GmbH & Co. KGaA.
- Motokura, Ken,Tanaka, Satoka,Tada, Mizuki,Iwasawa, Yasuhiro
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experimental part
p. 10871 - 10879
(2010/04/05)
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- Rational design of sugar-based-surfactant combined catalysts for promoting glycerol as a solvent
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The use of glycerol as a solvent for environmentally friendly organic reactions has been demonstrated. It was observed that the surfactant combined catalysts (SCCs) with glycerol can enhance the diffusion of organic substrate in the glycerol. The study found that micellar catalysis in glycerol form a unstable emulsions. The study also investigated the reaction of 1,2-epoxydodecane with dodecanoic acid at at temperature of 110°C in glycerol. Diethoanolamine with dodecanoic acid can be used as a phase-transfer agent which can accelerate the diffusion of organic substrate in the glycerol. The study also concluded that the surfactant need to be use with a catalysis to use glycerol as solvent for the improved diffusion of organic compounds. The study used renewable resources to provide an eco-friendly environment during all reactions.
- Karam, Ayman,Villandier, Nicolas,Delample, Mathieu,Koerkamp, Carmen Klein,Douliez, Jean-Paul,Granet, Robert,Krausz, Pierre,Barrault, Joel,Jerome, Francois
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supporting information; experimental part
p. 10196 - 10200
(2009/10/16)
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- Asymmetric multifunctional organocatalytic Michael addition of nitroalkanes to α,β-unsaturated ketones
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Cinchona alkaloid derived primary amine thioureas organocatalyzed Michael addition of nitroalkanes to enones in good yield and up to 98% ee and offered a new way to construct quaternary stereocenters from enones and nitroalkanes. The Royal Society of Chem
- Li, Pengfei,Wang, Yongcan,Liang, Xinmiao,Ye, Jinxing
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supporting information; experimental part
p. 3302 - 3304
(2009/02/04)
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- Asymmetric conjugate addition of nitroalkanes to enones with a chiral α-aminophosphonate catalyst
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Chiral diethyl (2R)-tetrahydropyrro-2-ylphosphonate is an effective catalyst for the Michael addition of nitroalkanes to α,β-unsaturated ketones. This study revealed that the hydrate salt of this α-aminophosphonate was found to be a better catalytic speci
- Malmgren, Marcus,Granander, Johan,Amedjkouh, Mohamed
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p. 1934 - 1940
(2008/12/22)
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- Magnesium-lanthanum mixed metal oxide: A strong solid base for the michael addition reaction
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Michael additions were achieved quantitatively at room temperature with a broad spectrum of acceptors and donors, using a magnesium-lanthanum mixed oxide, a strong solid base. The best solvent for the reaction is dimethylformamide, but good yields were al
- Veldurthy, Bhaskar,Clacens, Jean Marc,Figueras, Francois
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p. 767 - 771
(2007/10/03)
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- Use of a solid hydrotalcite structure incorporating fluorides for basic catalysis of michael or knoevenagel reactions
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The invention concerns the use of a solid basic catalyst comprising a hydrotalcite structure wherein part at least of the compensating anions are fluoride anions F? for producing Knoevenagel of Michael condensation reactions. The invention also concerns novel solid basic catalysts comprising a hydrotalcite structure characterised by a Mg/Al molar ratio ranging between 2.5 and 3.8 wherein at least part of the compensating anions are fluoride anions F?, and methods for preparing said novel catalysts.
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Page/Page column 5-6
(2008/06/13)
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- Novel heterobimetallic catalysts for asymmetric Michael reactions
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The newly developed chiral catalysts 1 and 2 show opposite enantioselectivity in Michael addition reactions of cyclic enones and malonates resulting in the production of both enantiomers of products in good chemical yield and enantiomeric excess. 27
- Velmathi,Swarnalakshmi,Narasimhan
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p. 113 - 117
(2007/10/03)
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- Catalytic C-C bond formation promoted by Mg-Al-O-t-Bu hydrotalcite
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Mg-Al-O-t-Bu-hydrotalcite catalyst was found to be an efficient, environmentally attractive and selective solid base catalyst for 1,4 Michael addition. Mg-Al-O-t-Bu hydrotalcite is also effective for simple synthesis of α,β-unsaturated esters and nitriles by condensation of the corresponding activated carboxylic esters or nitriles with various aldehydes by Knoevenagel condensation. These reactions proceeded at room temperature at a greater rate in the presence of Mg-Al-O-t-Bu hydrotalcite than in the presence of any of the other catalysts examined. (C) 2000 Elsevier Science Ltd.
- Choudary,Lakshmi Kantam,Kavita,Venkat Reddy,Figueras
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p. 9357 - 9364
(2007/10/03)
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- Catalytic asymmetric conjugate addition of nitroalkanes to cycloalkenones
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Nitroalkanes add to cyclic and acyclic enones in an enantioselective manner in the presence of catalytic quantities of L-proline and trans2,5-dimethylpiperazine as excess additive.
- Hanessian, Stephen,Pham, Vinh
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p. 2975 - 2978
(2007/10/03)
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- Organic reaction in water. Part 21: Michael addition in water without phase transfer agents
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The Michael additions of dicarbonyl compounds, nitroalkanes, and thiols to 2-cyclohexen-1-one can be accomplished in water without phase transfer agents. The reaction is extremely sensitive to the pH of the reaction media, and therefore, the methodology c
- Da Silva, Flavia Martins,Gomes, Adriana Kniaseff,Jones Jr., Joel
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p. 624 - 627
(2007/10/03)
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- Michael additions catalysed by N,N-dimethyl-3-aminopropyl - Derivatised amorphous silica and Hexagonal Mesoporous Silica (HMS)
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Solid bases prepared by derivatisation of amorphous silica and hexagonal mesoporous silica with dimethylaminopropyl groups are good catalysts for Michael addition reactions. Of the prepared catalysts, those based on hexagonal mesoporous silica show partic
- Mdoe, James E. G.,Clark, James H.,Macquarrie, Duncan J.
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p. 625 - 627
(2007/10/03)
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- Clemmensen Reduction. XI. Fragmentation Reactions of Some 3-Acetylcycloalkanones
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Clemmensen reduction of a series of 3-acetylcycloalkanones yields, as the major product, an acyclic unsaturated ketone, the product of fragmentation.Some normal carbonyl-methylene reduction also occurs.A mechanistic rationale for the fragmentation is advanced.
- Bailey, Karen E.,Davis, Brian R.
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p. 1827 - 1834
(2007/10/03)
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