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Showing papers on "Methyl vinyl ketone published in 2014"


Journal ArticleDOI
TL;DR: The aqueous phase conversion of the first generation isoprene oxidation products can potentially contribute to tropospheric aqueously phase budgets of important carbonyl and dicarbonyl components which are expected to be conducive to the formation of aqSOA.
Abstract: Kinetic and mechanistic studies were conducted on the isoprene oxidation products methacrolein, methyl vinyl ketone, methacrylic and acrylic acid reacting with hydroxyl and nitrate radicals and sulfate radical anions in aqueous solution by use of the laser flash photolysis technique and a reversed-rate method for kinetics. High-performance liquid chromatography/mass spectrometry was applied for product analysis. The kinetic investigations show the highest reactivity of the hydroxyl radical followed by sulfate and nitrate radicals. For methacrolein and methyl vinyl ketone the following rate constants have been determined at 298 K: k(OH+methacrolein) = (9.4 ± 0.7) × 109 M−1 s−1, k(OH+methylvinylketone) = (7.3 ± 0.5) × 109 M−1 s−1, k(NO3+methacrolein) = (4.0 ± 1.0) × 107 M−1 s−1, k(NO3+methylvinylketone) = (9.7 ± 3.4) × 106 M−1 s−1, k(SO4−+methacrolein) = (9.9 ± 4.9) × 107 M−1 s−1 and k(SO4−+methylvinylketone) = (1.0 ± 0.2) × 108 M−1 s−1. Temperature and pH dependencies of the reactions of OH, NO3 and SO4− with methacrolein, methyl vinyl ketone, methacrylic and acrylic acid as well as Arrhenius parameters have been obtained and discussed. Product studies were performed on the OH radical induced oxidation of methacrolein and methyl vinyl ketone. In the reaction of methacrolein + OH methylglyoxal and hydroxyacetone were identified as first oxidation products with yields of 0.099 and 0.162. Methylglyoxal was primarily produced in the oxidation of methyl vinyl ketone with a yield of 0.052. For both precursor compounds the formation of glycolaldehyde was observed for the first time with yields of 0.051 and 0.111 in the oxidation of methacrolein and methyl vinyl ketone, respectively. Furthermore, highly functionalised C4 compounds were determined from the oxidation of both precursor compounds, but for the first time for methyl vinyl ketone. Reaction schemes were developed based on known peroxyl radical reaction mechanisms. The aqueous phase conversion of the first generation isoprene oxidation products can potentially contribute to tropospheric aqueous phase budgets of important carbonyl and dicarbonyl components which are expected to be conducive to the formation of aqSOA.

61 citations


Journal ArticleDOI
TL;DR: In this paper, the authors conducted kinetic investigations of non-radical reactions using UV/Vis spectroscopy (dual-beam spectrophotometer and stopped flow technique) and a capillary electrophoresis system applying pseudo-first order kinetics to reactions of glyoxal, methylglyoxal and methyl vinyl ketone with H2O2 and ozone at 298 K.
Abstract: . Free radical reactions are an important degradation process for organic compounds within the aqueous atmospheric environment. Nevertheless, non-radical oxidants such as hydrogen peroxide and ozone also contribute to the degradation and conversion of these substances (Tilgner and Herrmann, 2010). In this work, kinetic investigations of non-radical reactions were conducted using UV / Vis spectroscopy (dual-beam spectrophotometer and stopped flow technique) and a capillary electrophoresis system applying pseudo-first order kinetics to reactions of glyoxal, methylglyoxal, glycolaldehyde, glyoxylic, pyruvic and glycolic acid as well as methacrolein (MACR) and methyl vinyl ketone (MVK) with H2O2 and ozone at 298 K. The measurements indicate rather small rate constants at room temperature of k2nd

61 citations


Journal ArticleDOI
TL;DR: In this paper, the photochemistry of pyruvic acid was used to trigger the oligomerization of methyl vinyl ketone (MVK), an α,β-unsaturated compound generated by the atmospheric oxidation of isoprene.
Abstract: Aqueous phase oxidation reactions in atmospheric particles can yield high molecular weight products and create secondary organic aerosol (SOA) upon droplet evaporation. Oxidation by hydroxyl radicals to create oligomers in solution that form SOA has been previously investigated; however, mixed organic solutions that can initiate radical chemistry have been largely overlooked. In aqueous solution, pyruvic acid (PA), an α-keto acid found in both the gas and aqueous phases in the atmosphere, photolyzes via a radical mechanism. Here, we use this photochemistry of pyruvic acid to trigger oligomerization of methyl vinyl ketone (MVK), an α,β-unsaturated compound generated by the atmospheric oxidation of isoprene. We closely compare the reaction products and mechanism to a recent work in which the radical oligomerization of MVK initiated by hydroxyl radical is studied in depth. Using mass spectrometry, it is shown that the two reactions create oligomers of similar molecular weights, up to m/z 1200 for initial MVK...

43 citations


Journal ArticleDOI
TL;DR: In situ IR spectroscopy and DFT calculations show that major conformational effects are involved, controlled mainly by steric effects of carbonyl substituents, resulting in a model that provides simple and predictable preparation of α,β-unsaturated imines for in situ utilization in synthesis.
Abstract: A combination of in situ IR spectroscopy (ReactIR) and DFT calculations have been used to understand what factors govern the selectivity in the addition of primary amines to α,β-unsaturated aldehydes and ketones, ie, 1,2- versus 1,4-addition It has been found that the 1,2-addition products (α,β-unsaturated imines following addition and elimination) usually predominate for most systems However, exceptions, such as methyl vinyl ketone, selectively give 1,4-addition products This has been rationalized by DFT calculations that show that major conformational effects are involved, controlled mainly by steric effects of carbonyl substituents, resulting in a model that provides simple and predictable preparation of α,β-unsaturated imines for in situ utilization in synthesis

40 citations


Journal ArticleDOI
17 Dec 2014-Synlett
TL;DR: This account describes the use of phosphines as simple organocatalysts that catalyze the synthesis of complex spirocyclic compounds and their applications, including asymmetric variants and synthetic applications.
Abstract: This account describes the use of phosphines as simple organocatalysts that catalyze the synthesis of complex spirocyclic compounds. Besides our own results, coverage of relevant literature in this field is also provided, including asymmetric variants and synthetic applications. 1 Introduction 2 Cycloaddition Reactions Involving Allenoates or 2-Butynoates 2.1 [3+2] Cycloadditions 2.2 [4+2] Cycloadditions 2.3 [4+1] Cycloadditions 3 [3+2] Cycloadditions with Morita–Baylis–Hillman Adducts 4 Cycloaddition Reactions Using Ynone Derivatives 5 Cycloaddition Reactions Involving Methyl Vinyl Ketone ­ Derivatives 6 Miscellaneous Reactions 7 Conclusions

39 citations


Journal ArticleDOI
TL;DR: Ten lipases and esterases have been examined to catalyse the reaction between p-nitrobenzaldehyde and methyl vinyl ketone, the Baylis–Hillman reaction, to form 3-[hydroxyl-(4-nitrophenyl)-methyl]-but-3-en-2-one, and Escherichia coli BioH esterase had the best activity.
Abstract: Ten lipases and esterases have been examined to catalyse the reaction between p-nitrobenzaldehyde and methyl vinyl ketone, the Baylis-Hillman reaction, to form 3-[hydroxyl-(4-nitrophenyl)-methyl]-but-3-en-2-one. Among these enzymes, Escherichia coli BioH esterase had the best activity. Optimal conditions for this reaction were: 0.1 mmol aldehyde, 0.1 mmol activated alkene, 30 mg E. coli BioH, 1 ml acetonitrile at 30 °C for 96 h. In addition to the named substrates, four other aldehydes and three activated alkenes were also investigated to determine the substrate range of the enzyme. The structures of nine products were confirmed by NMR and yields of the corresponding products ranged from 21 to 46 %.

22 citations


Journal ArticleDOI
TL;DR: A highly selective intramolecular trans-silylvinylation of internal alkynes catalyzed by RuHCl(CO)(SIMes)(PPh3) has been accomplished and the use of methyl vinyl ketone as an additive increased the efficiency of this transformation.

18 citations


Journal ArticleDOI
TL;DR: Alkylation of 1-hydroxy-1H-[1,2,3]triazolo[4,5-e]tetrazine 5,7-dioxides was studied in this article.
Abstract: Alkylation of 1-hydroxy-1H-[1,2,3]triazolo[4,5-e][1,2,3,4]tetrazine 5,7-dioxide 1 and its silver salt 10 with different alkylating agents (diazomethane, diazoacetone, bromoacetone, α-bromoacetophenone, methyl iodide, methyl vinyl ketone) was studied. Alkylation of compound 1 with diazo compounds and salt 10 with halocompounds results predominantly in O-alkylation products, 1-alkoxy-1H-[1,2,3]triazolo[4,5-e][1,2,3,4]tetrazine 5,7-dioxides. The Michael reaction of compound 1 with methyl vinyl ketone involves the triazole nitrogen atom to give 1-(3-oxobutyl)-1H-[1,2,3]triazolo[4,5-e][1,2,3,4]tetrazine 3,4,6-trioxide. The structures of the compounds synthesized were established by 1H, 13C, 14N NMR spectroscopy and mass spectrometry.

15 citations


Journal ArticleDOI
TL;DR: Key steps of the synthetic sequence are the Robinson annulation of a β-ketoester and methyl vinyl ketone and an unprecedented cyclization of the resulting α,β-enone, which is mediated by tin(IV) chloride in the presence of N-phenylselenophthalimide.
Abstract: Synthesis of the putative structure of the marine natural 15-oxopuupehenoic acid has been achieved starting from commercial (−)-sclareol. Key steps of the synthetic sequence are the Robinson annulation of a β-ketoester and methyl vinyl ketone and an unprecedented cyclization of the resulting α,β-enone, which is mediated by tin(IV) chloride in the presence of N-phenylselenophthalimide. The physical properties of the synthetic compound are somewhat different from those reported for the natural product.

11 citations


Journal ArticleDOI
TL;DR: In this paper, a cycloaddition of 4-halo derivatives of 6,6-dimethoxycyclohexa-2,4-dienones known as orthoquinone monoketals/masked o-benzoquinones is described.
Abstract: The studies on [4 + 2] cycloaddition of 4-halo derivatives of 6,6-dimethoxycyclohexa-2,4-dienones known as orthoquinone monoketals/masked o-benzoquinones are described. The 4-fluoro, 4-chloro- and 4-iodo-masked o-benzoquinones were stable enough for their isolation and characterization. These conjugated dienones cycloadded with several electron-deficient and electron-rich dienophiles in a highly regio- and stereo-selective manner to afford the corresponding halo bicyclo[2.2.2]octenone derivatives in high to excellent chemical yields. The halo masked o-benzoquinones did not undergo dimerization under the reaction conditions. To evaluate the observed selectivities of these Diels–Alder reactions, we have performed quantum mechanical calculations for the reactions between halo masked o-benzoquinones and methyl vinyl ketone and ethyl vinyl ether at the B3LYP/6-31G** theory level. The differences in HOMO and LUMO energy gaps suggest that these reactions can be classified as inverse electron-demand Diels–Alder reactions. The calculated transition state energies and global electronic indexes supported the experimentally observed selectivities of the reaction in many cases.

11 citations


Journal ArticleDOI
TL;DR: The guanidine organocatalyst, ChibaG, was bound via an ether linkage to the phenyl group of the 2-imino substituent to Merrifield resin this article.
Abstract: The guanidine organocatalyst, ChibaG, was bound via an ether linkage to the phenyl group of the 2-imino substituent to Merrifield resin. Polystyrene-bound ChibaG acted as an effective catalyst in the Michael reaction of tert-butyl N-(diphenylmethylidene)glycinate with methyl vinyl ketone, and could be recovered and reused many times.

Journal ArticleDOI
TL;DR: In this paper, a faceted silica tube functionalized with sulfated zirconia was prepared and used to catalyze Michael addition reaction of indole with methyl vinyl ketone.

Journal ArticleDOI
TL;DR: In a rational chiral molecular design of chalcogenides, optically active thiepin with C2-symmetric chirality was synthesized from commercially available thiophene as discussed by the authors.
Abstract: In a rational chiral molecular design of chalcogenides, optically active thiepin with C2-symmetric chirality was synthesized from commercially available thiophene. Then enatioselective Chalcogeno-Baylis-Hillman reactions of arylaldehydes with methyl vinyl ketone (MVK) and acrylates were investigated in the presence of thiepin-Lewis acid complex. Finally, up to 64% ee was achieved in the presence of 0.2 equiv. of (S)-thiepin at 20°C.

Journal ArticleDOI
TL;DR: In this paper, 3-Aryl-5-hydroxyl 5-vinylisoxazoles were synthesized by reacting aryl nitrile oxides with the lithium enolate of methyl vinyl ketone (MVK) at −78°C.
Abstract: 3-Aryl-5-hydroxy-5-vinyl-2-isoxazolines were synthesized by reacting aryl nitrile oxides with the lithium enolate of methyl vinyl ketone (MVK) at –78 °C. Fair to good yields are obtained in the case of aryl nitrile oxides bearing electron-withdrawing groups on the aryl moiety or less bulky groups. Conversely, lower yields or no reaction was observed in the presence of hindered aryl nitrile oxides. Such a behavior was confirmed by ab initio calculations of the activation energies for three reactions. A number of 3-aryl-5-vinylisoxazoles were quantitatively obtained by dehydration/aromatization of the corresponding 5-hydroxy-2-isoxazolines under acidic conditions. The side-chain elaboration is reported as a synthetic utility of some vinylisoxazoles and vinylisoxazo­lines.

Journal ArticleDOI
TL;DR: In this paper, a general strategy for the assembly of previously unknown tris(β,β,γ-oximinoalkyl)amines from aliphatic nitro compounds and methyl vinyl ketone is described.

Journal ArticleDOI
TL;DR: In this article, a non-oxidative approach to the preparation of N-formyl-substituted aminoketones was proposed, where N,N-dimethyl-N′-(2-pyridyl)formamidine was treated with methyl vinyl ketone under microwave irradiation.
Abstract: Abstract Treatment of N,N-dimethyl-N′-(2-pyridyl)formamidine with methyl vinyl ketone under microwave irradiation yields N-formyl-N-(3-oxobutyl)-2-pyridylamine without decomposition or polymerization of methyl vinyl ketone. The result is an alternative non-oxidative approach to the preparation of N-formyl-substituted aminoketones.

Journal ArticleDOI
TL;DR: In this article, a fluorine-containing 1,3-thiazine derivatives were obtained by the reactions of primary polyfluoroalkanethioamides with methyl vinyl ketone and ethyl acrylate in the presence of boron trifluoride etherate.



Journal ArticleDOI
Abstract: A series of pyrrolizidines bearing a methyl group at C-5 are synthesized by 1,3-dipolar cycloaddition of five-membered cyclic nitrones with methyl vinyl ketone.

Journal ArticleDOI
TL;DR: In a rational chiral molecular design of chalcogenides, optically active thiepin with C2-symmetric chirality was synthesized from commercially available thiophene as discussed by the authors.
Abstract: In a rational chiral molecular design of chalcogenides, optically active thiepin with C2-symmetric chirality was synthesized from commercially available thiophene. Then enatioselective Chalcogeno-Baylis-Hillman reactions of arylaldehydes with methyl vinyl ketone (MVK) and acrylates were investigated in the presence of thiepin-Lewis acid complex. Finally, up to 64% ee was achieved in the presence of 0.2 equiv. of (S)-thiepin at 20°C.

Journal ArticleDOI
TL;DR: A palladium(II)-catalyzed highly regioselective tandem reaction of o-alkynylbenzoates with methyl vinyl ketone for the synthesis of isocoumarins was developed as discussed by the authors.
Abstract: A palladium(II)-catalyzed highly regioselective tandem reactions of o-alkynylbenzoates with methyl vinyl ketone for the synthesis of isocoumarins was developed. It is a convenient, mild and environmentally benign reaction with moderate to high yield. The