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Methyl vinyl ketone

About: Methyl vinyl ketone is a research topic. Over the lifetime, 1510 publications have been published within this topic receiving 26839 citations. The topic is also known as: 3-buten-2-one & gamma-oxo-alpha-butylene.


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Journal ArticleDOI
TL;DR: Pd(0)-catalyzed conjugate addition of benzylzinc chloride to methyl vinyl ketone in the presence of chlorotrimethylsilane and lithium chloride in an atmosphere of carbon monoxide at room temperature afforded 1-phenyl-2,5-hexanedione monosilyl enol ether.
Abstract: Pd(0)-catalyzed conjugate addition of benzylzinc chloride to methyl vinyl ketone in the presence of chlorotrimethylsilane and lithium chloride in an atmosphere of carbon monoxide at room temperature afforded 1-phenyl-2,5-hexanedione monosilyl enol ether. In this catalytic carbonylation, four components are connected in one reaction. Successive acidic workup generated a variety of 1,4-diketones from substituted benzylzinc chlorides or related compounds and α,β-enones. Some products were converted to cyclopentenones or five-membered heterocyclic compounds containing an N, O, or S atom.

53 citations

Journal ArticleDOI
TL;DR: In this article, the effect of the para substituents on the partial charge at the palladium(II) center was investigated by means of the Mulliken population analysis, and it was found that various para functionalities can be used for immobilization of the pincer−metal complexes without affecting the catalytic activity of individual sites.
Abstract: Several para-substituted NCN-pincer palladium(II) complexes (1a−g and 6a−g) {NCN = [C6H3(CH2NMe2)2-2,6]−, para = 4-position} have been prepared and the electronic influences of the para substituents were studied in catalysis as well as by DFT calculations (B3LYP/LANL2DZ). From DFT calculations, it was found that the para substituent exerts only a minor effect on the partial charge, investigated by means of the Mulliken population analysis, at the palladium(II) center. Also, when the para-functionalized, cationic NCN−PdII complexes 6a−g were applied as Lewis acid catalysts in the double Michael reaction between methyl vinyl ketone and ethyl α-cyanoacetate, only small differences in the activities of the various catalysts were observed. These results, when translated to immobilized multipincer catalysts, imply that various para functionalities can be used for immobilization of the pincer−metal complexes without affecting the catalytic activity of the individual sites. The application of a number of shape-persistent nanosize (NCN−PdII)n complexes (7, n = 3; 8, n = 3; 9, n = 8; 10, n = 12) as homogeneous catalysts in the same Michael reaction, confirmed this expectation. For complexes 7, 8 and 9, the catalytic activity per PdII center was found to be the same as for the monopincer analogs. Only dodecakis(NCN−PdII) complex 10 showed an almost threefold enhancement in catalytic activity per PdII center, which is ascribed to the high catalyst concentration at the periphery of this material. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

53 citations

Journal ArticleDOI
TL;DR: A survey over X-ray absorption methods in homogeneous catalysis research is given with the example of the iron-catalyzed Michael addition reaction and a dedicated experimental set-up for three-dimensional spectroscopic studies of homogeneous catalytic reactions under laboratory conditions is presented.
Abstract: A survey over X-ray absorption methods in homogeneous catalysis research is given with the example of the iron-catalyzed Michael addition reaction. A thorough investigation of the catalytic cycle was possible by combination of conventional X-ray absorption spectroscopy (XAS), resonant inelastic X-ray scattering (RIXS) and multi-dimensional spectroscopy. The catalytically active compound formed in the first step of the Michael reaction of methyl vinyl ketone with 2-oxocyclopentanecarboxylate (1) could be elucidated in situ by RIXS spectroscopy, and the reduced catalytic activity of FeCl3·6H2O (2) compared to Fe(ClO4)3·9H2O (3) could be further explained by the formation of a [FeIIICl4−]3[FeIII(1-H)2(H2O)2+][H+]2 complex. Chloride was identified as catalyst poison with a combined XAS-UV/vis study, which revealed that Cl− binds quantitatively to the available iron centers that are deactivated by formation of [FeCl4−]. Operando studies in the course of the reaction of methyl vinyl ketone with 1 by combined XAS-Raman spectroscopy allowed the exclusion of changes in the oxidation state and the octahedral geometry at the iron site; a reaction order of two with respect to methyl vinyl ketone and a rate constant of k = 1.413 min−2 were determined by analysis of the CC and CO vibration band. Finally, a dedicated experimental set-up for three-dimensional spectroscopic studies (XAS, UV/vis and Raman) of homogeneous catalytic reactions under laboratory conditions, which emerged from the discussed investigations, is presented.

52 citations

Journal ArticleDOI
TL;DR: In this paper, the authors used discharge-flow and relative-rate techniques to obtain the rate coefficients for the reactions: NO3+CH3C(O)CHCHCH2→products (1), NO3 + CH2C(CH3)CH3 → products (2), NO 3+CH2CHCHO→ products (3), and NO3+, CH2CHCHC (O)OCH3→product (4).
Abstract: Absolute and relative-rate techniques have been used to obtain rate coefficients for the reactions: NO3+CH3C(O)CHCH2→products (1), NO3+CH2C(CH3)CHO→products (2), NO3+CH2CHCHO→ products (3), and NO3+CH2CHC(O)OCH3→products (4). The reaction NO3+CH2C(CH3)C(O)OCH3→ products (5), has been investigated by a relative-rate method only. The rate coefficients obtained by the relative-rate method at T=296±2 K and P=760 Torr are k1=(4.7±1.7)×10-16 cm3 molecule-1 s-1, k2=(3.7±1.0)×10-15 cm3 molecule-1 s-1, k3=(1.1±0.4)×10-15 cm3 molecule-1 s-1, k4=(1.0±0.6)×10-16 cm3 molecule-1 s-1 and k5=(3.6±1.3)×10-15 cm3 molecule-1 s-1. The rate coefficients determined by the discharge-flow technique at low pressure (P=1–10 Torr) and at T=293–303 K are k1=(3.2±0.6)×10-16 cm3 molecule-1 s-1, k2=(9.6±2.0)×10-15 cm3 molecule-1 s-1, k3=(8.9±2.8)×10-15 cm3 molecule-1 s-1, k4=(1.9±0.4)×10-16 cm3 molecule-1 s-1. The discrepancy between the values obtained from the relative-rate technique and the absolute technique are discussed and explained in terms of interference in the absolute study caused by secondary chemistry and fast-reacting impurities. Product studies reveal that methyl glyoxal is a product of reactions (1) and (2) along with peroxymethacryloyl nitrate (MPAN) for reaction (2) in air. A diurnally varying boundary-layer model suggests that reaction (2) is an important loss process for methacrolein and that it can lead to the generation of OH at night.

52 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20238
202249
202121
202020
201910
201817