scispace - formally typeset
Search or ask a question

Showing papers on "Methyl vinyl ketone published in 2012"


Journal ArticleDOI
TL;DR: In this paper, the selective hydrogenation of unsaturated ketones (methyl vinyl ketone and benzalacetone) and unsaturated aldehydes (crotonaldehyde and cinnamaldehyde) was carried out with H2 at 2 bar absolute over Pd/C, Pt/C and Ru/C catalysts in ethanol or water solvent at 333 K.
Abstract: The selective hydrogenation of unsaturated ketones (methyl vinyl ketone and benzalacetone) and unsaturated aldehydes (crotonaldehyde and cinnamaldehyde) was carried out with H2 at 2 bar absolute over Pd/C, Pt/C, Ru/C, Au/C, Au/TiO2, or Au/Fe2O3 catalysts in ethanol or water solvent at 333 K. Comparison of the turnover frequencies revealed Pd/C to be the most active hydrogenation catalyst, but the catalyst failed to produce unsaturated alcohols, indicating hydrogenation of the C═C bond was highly preferred over the C═O bond on Pd. The Pt and Ru catalysts were able to produce unsaturated alcohols from unsaturated aldehydes, but not from unsaturated ketones. Although Au/Fe2O3 was able to partially hydrogenate unsaturated ketones to unsaturated alcohols, the overall hydrogenation rate over gold was the lowest of all of the metals examined. First-principles density functional theory calculations were therefore used to explore the reactivity trends of methyl vinyl ketone (MVK) and benzalacetone (BA) hydrogenati...

179 citations


Journal ArticleDOI
TL;DR: This method provides bridged-ring indoline scaffolds containing two quaternary carbon centers with excellent yields and enantioselectivity (up to 98% yield and 98% ee).

94 citations


Journal ArticleDOI
TL;DR: In this article, the ability of methacrolein (MACR) and methyl vinyl ketone (MVK) to form oligomers and secondary organic aerosol (SOA) upon aqueous phase OH-oxidation and subsequent water evaporation was investigated.

63 citations


Journal ArticleDOI
TL;DR: Blue-shifts seen upon treatment of H-bonding catalysts with the colorimetric compound 7-methyl-2-phenylimidazo[1,2-a]pyrazin-3(7H)-one correlate well to the K(eq) of binding to the sensor.
Abstract: A sensor has been developed to quickly and simply assess the relative reactivity of different hydrogen-bonding catalysts. Specifically, blue-shifts seen upon treatment of H-bonding catalysts with the colorimetric compound 7-methyl-2-phenylimidazo[1,2-a]pyrazin-3(7H)-one correlate well to the Keq of binding to the sensor. The blue-shifts also show a high degree of correlation with relative rates in Diels–Alder reactions of methyl vinyl ketone and cyclopentadiene employing the H-bonding catalysts. The relevance of the sensor blue-shifts to the LUMO-lowering abilities of the H-bonding catalysts is discussed.

35 citations


Journal ArticleDOI
TL;DR: The ortho-metalated complex [Pd{C,N-C6H 2CH2CH2NH2-2,(OMe)2-4,5}(μ-Br)] as discussed by the authors is derived from homoveratrylamine derived from methyl vinyl ketone, or 2-norbornene.

29 citations


Journal ArticleDOI
TL;DR: In this article, the authors performed a laboratory experiment of the aqueous ozonolysis of isoprene at different pHs (3 −7) and temperatures (4 −25 °C).
Abstract: . The aqueous phase reaction of volatile organic compounds (VOCs) has not been considered in most analyses of atmospheric chemical processes. However, some experimental evidence has shown that, compared to the corresponding gas phase reaction, the aqueous chemical processes of VOCs in the bulk solutions and surfaces of ambient wet particles (cloud, fog, and wet aerosols) may potentially contribute to the products and formation of secondary organic aerosol (SOA). In the present study, we performed a laboratory experiment of the aqueous ozonolysis of isoprene at different pHs (3–7) and temperatures (4–25 °C). We detected three important kinds of products, including carbonyl compounds, peroxide compounds, and organic acids. Our results showed that the molar yields of these products were nearly independent of the investigated pHs and temperatures, those were (1) carbonyls: 56.7 ± 3.7 % formaldehyde, 42.8 ± 2.5 % methacrolein (MAC), and 57.7 ± 3.4 % methyl vinyl ketone (MVK); (2) peroxides: 53.4 ± 4.1 % hydrogen peroxide (H2O2) and 15.1 ± 3.1 % hydroxylmethyl hydroperoxide (HMHP); and (3) organic acids: undetectable (

28 citations


Journal ArticleDOI
TL;DR: The enantioselective conjugate addition reaction of 3-aryl-substituted oxindoles with methyl vinyl ketone promoted by binaphthyl-modified bifunctional organocatalysts was investigated.
Abstract: The enantioselective conjugate addition reaction of 3-aryl-substituted oxindoles with methyl vinyl ketone promoted by binaphthyl-modified bifunctional organocatalysts was investigated. The corresponding Michael adducts, containing a quaternary center at the C3-position of the oxindoles, were generally obtained in high yields with excellent enantioselectivities (up to 91% ee).

26 citations


Journal ArticleDOI
TL;DR: In this article, spiro-β-lactam derivatives have been prepared via stereoselective 1,3-dipolar cycloaddition of 6-diazopenicillanates using dipolarophiles such as acrylonitrile, acrylates or methyl vinyl ketone.

25 citations


Journal ArticleDOI
TL;DR: The enantioselective conjugate addition reaction of prochiral 3-alkyl-substituted oxindoles with vinyl ketones catalyzed by binaphthyl-modified bifunctional organocatalysts bearing both central and axial chiral elements is described.
Abstract: phosphate. 5 Although there have been reports for the catalytic enantioselective conjugate addition reaction of 3-aryl-substituted oxindoles to vinyl ketones, 5 a few examples for the catalytic enantioselective conjugate addition reaction of 3alkyl-substituted oxindoles to cyclic enones were reported using chiral primary or secondary amine catalysts. 6 Therefore, the development of alternative catalysts for the catalytic enantioselective conjugate addition reaction of 3-alkyl-substituted oxindoles to vinyl ketones would be highly desirable. As part of the research program toward the development of synthetic methods for the catalytic carbon-carbon bond formations, 7 we recently reported the organocatalytic conjugate addition reaction to α,β-unsaturated carbonyl compounds 8 and the other Michael acceptors. 9 In this communications, we wish to describe the enantioselective conjugate addition reaction of prochiral 3-alkyl-substituted oxindoles with vinyl ketones catalyzed by binaphthyl-modified bifunctional organocatalysts bearing both central and axial chiral elements. In an attempt to validate the feasibility of the organocatalytic enantioselective conjugate addition reaction of 3substituted oxindoles, we first investigated the reaction system with 3-benzyl oxindole 1a with methyl vinyl ketone (2a) in the presence of 10 mol % of catalyst in toluene at room temperature. We examined the impact of the structure of catalysts I-IV on enantioselectivities (Table 1, entries 1-4). Quinine-derived thiourea catalyst I was ineffective (Table 1, entriry 1). While binaphthyl-modified chiral bifunctional organocatalysts II-III bearing both central and axial chiral

19 citations


Journal ArticleDOI
TL;DR: The combination of methyl 3,7-dioxo-2-diazo-4-octenoate from the zinc triflate catalyzed Mukaiyama-Michael reaction with Michael acceptors in the presence of a catalytic amount of base provides convenient access to highly substituted resorcinol derivatives.
Abstract: The combination of methyl 3,7-dioxo-2-diazo-4-octenoate from the zinc triflate catalyzed Mukaiyama–Michael reaction of methyl 3-tert-butylsilyloxy-2-diazobutenoate and 4-methoxy-3-buten-2-one with Michael acceptors (methyl vinyl ketone, N-phenylmaleimide, β-nitrovinylarenes) in the presence of a catalytic amount of base provides convenient access to highly substituted resorcinol derivatives. This transformation is achieved in an efficient one-pot multi-component transformation by the sequential addition of the reagents.

15 citations


Journal ArticleDOI
TL;DR: An efficient catalyst for Ferrier rearrangement and hetero-Michael addition was successfully generated from a sacrificial zirconium anode into media containing reactants for these reactions as discussed by the authors.

Journal ArticleDOI
TL;DR: The aqua complexes (SM,RC)-[(η5-C5Me5)M(PROPHOS)(H2O)][SbF6]2 are active catalysts for the asymmetric Diels-Alder reaction between ketones and dienes and achieve enantioselectivities of up to 89% ee as discussed by the authors.

Journal ArticleDOI
TL;DR: In this article, the catalytic effect of iodine on the Mukaiyama-Michael reaction has been evaluated experimentally taking three representative silyl enolates, which react effectively with various α,β-unsaturated ketones in the presence of 10 mol% of iodine giving 1,5-dicarbonyl products in 74%-87% yield.

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a method to solve the problem of artificial neural networks in the context of artificial intelligence, where the authors presented a method based on artificial neural network.
Abstract: Ministry of Science and Technology of China [2010CB732201]; National Natural Science Foundation of China [U0733001, 50776035]

Reference EntryDOI
TL;DR: Wieland Miescher ketone (WMK) as discussed by the authors, 1,3-cyclohexane-1.3-dione, methyl vinyl ketone.
Abstract: (S)-8a-Methyl-3,4,8,8a-tetrahydro-1,6(2H,7H)-naphtalenedione 2-Methyl-2-(3-oxobutyl)-1,3-cyclohexanedione 2-Methyl-1,3-cyclohexanedione N-Tosyl-(Sa)-binam-L-prolinamide Methyl vinyl ketone Keywords: Wieland Miescher ketone (WMK); fractional crystallization; natural product synthesis; 2- methylcyclohexane-1,3-dione; (S)-8a-Methyl-3,4,8,8a-tetrahydro-1,6(2H,7H)-naphtalenedione; N-tosyl-(Sa)-binam-L-prolinamide organocatalysis

Journal ArticleDOI
TL;DR: In this article, a simple and convenient procedure was proposed for the synthesis of 4-aryl-3-bromobutan-2-ones from methyl vinyl ketone and arenediazonium bromides under Meerwein reaction conditions.
Abstract: A simple and convenient procedure was proposed for the synthesis of 4-aryl-3-bromobutan-2-ones from methyl vinyl ketone and arenediazonium bromides under Meerwein reaction conditions.

Journal ArticleDOI
TL;DR: Triphenylphosphazenes reacted with methyl vinyl ketone, methyl acrylate, methyl methacrylate and dimethyl maleate to give the corresponding substituted dihydropyrazoles as discussed by the authors.
Abstract: Triphenylphosphazenes reacted with methyl vinyl ketone, methyl acrylate, methyl methacrylate, and dimethyl maleate to give the corresponding substituted dihydropyrazoles.

Journal ArticleDOI
TL;DR: In this paper, a simple chemoenzymatic method for the preparation of optically active (5-aryltetrazolyl-2)-4-butan-2-ol and their acetates has been developed.
Abstract: A simple chemoenzymatic method for the preparation of optically active (5-aryltetrazolyl-2)-4-butan-2-ol, (5-aryltetrazolyl-2)-propan-2-ol, and their acetates has been developed. The starting compounds (5-aryltetrazolyl-2)-4-butan-2-one and (5-aryltetrazolyl-2)-propan-2-one were obtained by a Michael-type addition of 5-aryl substituted tetrazoles to methyl vinyl ketone, and alkylation of 5-aryl substituted tetrazoles with chloroacetone, respectively. Their reduction with sodium borohydride afforded racemic mixtures of (5-aryltetrazolyl-2)-4-butan-2-oles and (5-aryltetrazolyl-2)-propan-2-oles.

Journal ArticleDOI
TL;DR: In this article, N-tosyl arylimines were used with methyl vinyl ketone and ethyl Vinyl ketone in the presence of ion-supported Ph3P A and B to give adducts, N-(2′-methylene-3′-oxo-1′)-4-methylbenzenesulfonamides, respectively, in good yields with high purity.

Journal ArticleDOI
TL;DR: The Baylis–Hillman reaction between arylaldehydes and methyl vinyl ketone was successfully realized by a catalytic amount of l-proline and l-histidine system to give the corresponding normal Baylis-Hillman adducts in moderate to high yields for the first time.
Abstract: Baylis–Hillman reaction between an aldehyde and an activated alkene, such as alkyl vinyl ketones, acrylates, acrylonitrile, and vinylsulfones, giving the β-hydroxy-α-methylene carbonyl compounds, is a versatile and atom-economical carbon–carbon bond-forming reaction. This reaction usually is catalyzed by strong Lewis bases such as tertiary amines and suffers from slow reaction rate. In this paper the Baylis–Hillman reaction between arylaldehydes and methyl vinyl ketone was successfully realized by a catalytic amount of l-proline and l-histidine system to give the corresponding normal Baylis–Hillman adducts in moderate to high yields for the first time. The effects of solvent and reagent electro property on the yields of this reaction were also investigated. Proline and histidine are naturally widely present amino acids in food system; furthermore, aldehydes and activated alkenes can also be easily produced in food processing, so proline and histidine co-catalyzed Baylis–Hillman reaction may find application in explaining some phenomena in food processing.

Journal ArticleDOI
TL;DR: Two domino reactions between salicyl N-thiophosphoryl imines and methyl vinyl ketone catalyzed by bifunctional phosphine catalysts and DBU provide two simple and efficient methods to construct chromans and chromens under mild conditions, respectively.
Abstract: We report two domino reactions between salicyl N-thiophosphoryl imines and methyl vinyl ketone catalyzed by bifunctional phosphine catalysts and DBU. These reactions provide two simple and efficient methods to construct chromans and chromens under mild conditions, respectively.

Journal ArticleDOI
TL;DR: In this paper, a stepwise mechanism for the uncatalyzed Michael addition of acetylacetone (AcAc) to methyl vinyl ketone (MVK) has been studied by ab initio calculations at the MP2/6-31+G (d, p)/B3LYP/6 −31+g (d, p) level of theory.
Abstract: A stepwise mechanism for the uncatalyzed Michael addition of acetylacetone (AcAc) to methyl vinyl ketone (MVK) has been studied by ab initio calculations at the MP2/6-31+G (d, p)// B3LYP/6-31+G (d, p) level of theory. This stepwise mechanism is initiated by a Diels–Alder-type attack of MVK on the double bond of the cis-enol of AcAc followed by cleavage of the cycloadduct and proton transfer leading to the formal Michael adduct. Nature of interaction between AcAc and MVK has been probed using reactivity descriptors defined within the context of conceptual DFT. This stepwise mechanism is found to have a low barrier than the concerted mechanism proposed earlier. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011



Journal ArticleDOI
TL;DR: In this article, the title reaction allows a new and efficient access to enantioenriched hexahydrocarbazoles and bridged ring indoline products, which can be used in a wide range of applications.
Abstract: The title reaction allows a new and efficient access to enantioenriched hexahydrocarbazoles and bridged ring indoline products.

Journal ArticleDOI
TL;DR: In this paper, 1H and 13C NMR and IR spectroscopy showed that 3-substituted naphthazarins with cyclohexenone and methyl vinyl ketone exist in CDCl3 solutions as mixtures of open-chain and cyclic tautomers, whereas the adducts with cyclopentenones exist only as the open chain forms.
Abstract: TsOH-Catalyzed reactions of 6,7-disubstituted 2-hydroxynaphthazarins and acyclic or cyclic α,β-enones afforded the corresponding Michael-type adducts, viz., 3-substituted naphthazarins in 17–78% yields. 1H and 13C NMR and IR spectroscopy showed that the adducts with cyclohexenone and methyl vinyl ketone exist in CDCl3 solutions as mixtures of open-chain and cyclic tautomers, whereas the adducts with cyclopentenones exist only as the open-chain forms.

Patent
30 May 2012
TL;DR: In this paper, a 2-halo ester was used to obtain an α-methyl-γ-keto acid ester with methyl vinyl ketone under basic conditions, followed by decarboxylation reaction and hydrolysis.
Abstract: The present invention relates to a method comprising (A) reacting a β-keto ester with a 2-halo ester under basic conditions to obtain a 2-aceto-3-methyl-succinic acid ester; (B) reacting the resulting 2-aceto-3-methyl-succinic acid ester with methyl vinyl ketone under basic conditions, optionally followed by a decarboxylation reaction and hydrolysis, etc, to obtain an α-methyl-γ-keto acid; and (C) reducing the resulting α-methyl-γ-keto acid to obtain wine lactone or a stereoisomer thereof or a mixture thereof Alternatively, the present invention relates to a method comprising step (A) as recited above; (B) reacting the resulting 2-aceto-3-methyl-succinic acid ester with methyl vinyl ketone under basic conditions, followed by decarboxylation reaction to obtain an α-methyl-γ-keto acid ester; and (E) reducing the resulting α-methyl-γ-keto acid ester in the presence of a ruthenium complex having a specific structure and in the presence of a hydrogen donor to obtain wine lactone or a stereoisomer thereof or a mixture thereof

Journal ArticleDOI
TL;DR: In this paper, different fluorinated amides are treated with methyl vinyl ketone or analogous esters to produce the desired γ- and δ-lactam units including optically active versions.
Abstract: Difluorinated amides are treated with methyl vinyl ketone or analogous esters to produce the desired γ- and δ-lactam units including optically active versions.

Journal ArticleDOI
TL;DR: In this article, a new procedure for the synthesis of α-bromo ketones (III) (17 examples) via Cu(II)-catalyzed reaction of arenediazonium bromides with methyl vinyl ketone is developed.
Abstract: A new procedure for the synthesis of α-bromo ketones (III) (17 examples) via Cu(II)-catalyzed reaction of arenediazonium bromides with methyl vinyl ketone is developed.