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.

Rate constants for the reactions of chlorine atoms with a series of unsaturated aldehydes and ketones at 298 K: structure and reactivity

Abstract: The kinetics and mechanisms of chlorine atom reactions with the products of organic oxidations in the atmosphere are of interest for understanding the chemistry of coastal areas. We report here the first kinetics measurements of the reactions of atomic chlorine with 4-chlorocrotonaldehyde and chloromethyl vinyl ketone, recently identified as products of the reaction of chlorine atoms with 1,3-butadiene. The reactions with acrolein, methacrolein, crotonaldehyde, methyl vinyl ketone and crotyl chloride were also studied to probe structure-reactivity relationships. Relative rate studies were carried out at 1 atm and 298 K using two different approaches: long path FTIR for the acrolein, methacrolein, crotonaldehyde and methyl vinyl ketone reactions with acetylene as the reference compound, and a collapsible Teflon reaction chamber with GC-FID detection of the organics using n-butane or n-nonane as the reference compounds for the entire series. The average absolute rate constants (in units of 10−10 cm3 molecule−1 s−1) determined using these techniques are as follows: acrolein (2.5 ± 0.7); methacrolein (2.9 ± 0.8); crotonaldehyde (3.2 ± 0.9); methyl vinyl ketone (2.0 ± 0.5); 4-chlorocrotonaldehyde (1.6 ± 0.4); chloromethyl vinyl ketone (2.0 ± 0.2); crotyl chloride (2.5 ± 0.2). The reported errors are ±2σ and include a reference rate constant error of 20% for acetylene, 10% for n-butane and 3% for n-nonane. These values are in good agreement with previous literature reports for the acrolein, methacrolein and methyl vinyl ketone reactions, while that for crotonaldehyde is 33% larger. The rate constant for acetylene using n-butane as the reference compound was also measured to be (5.23 ± 0.91) × 10−11 cm3 molecule−1 s−1 (2σ), in excellent agreement with the currently recommended value at 1 atm and 298 K. The effect of structure on reactivity of these compounds is discussed and it is shown that these fast reactions will be a major loss process for these compounds in coastal marine areas at dawn.

Metal Bis((perfluoroalkyl)sulfonyl)amides as Novel Lewis Acid Catalysts in Diels-Alder Reaction

Abstract: Some stable and lipophilic metal bis((perfluoroalkyl)sulfonyl)amides are prepared and employed as remarkable Lewis acid catalysts in the Diels-Alder reaction of cyclopentadiene with methyl vinyl ketone.

Ruthenium–Lewis Acid Catalyzed Asymmetric Diels–Alder Reactions between Dienes and α,β‐Unsaturated Ketones

Abstract: The complex [Ru(Cp)(R,R-BIPHOP-F)(acetone)][SbF(6)], (R,R)-1 a, was used as catalyst for asymmetric Diels-Alder reactions between dienes (cyclopentadiene, methylcyclopentadiene, isoprene, 2,3-dimethylbutadiene) and alpha,beta-unsaturated ketones (methyl vinyl ketone (MVK), ethyl vinyl ketone, divinyl ketone, alpha-bromovinyl methyl ketone and alpha-chlorovinyl methyl ketone). The cycloaddition products were obtained in yields of 50-90 % and with enantioselectivities up to 96 % ee. Ethyl vinyl ketone, divinyl ketone and the halogenated vinyl ketones worked best and their reactions with acyclic dienes consistently provided products with >90 % ee. alpha-Chlorovinyl methyl ketone performed better than alpha-bromovinyl methyl ketone. The reaction also provided a [4.3.1]bicyclic ring system in 95 % ee through an intramolecular cycloaddition reaction. Crystal structure determinations of [Ru(Cp)((S,S)-BIPHOP-F)(mvk)][SbF(6)], (S,S)-1 b, and [Ru(Cp)((R,R)-Me(4)BIPHOP-F)(acrolein)][SbF(6)], (R,R)-2 b, provided the basis for a rationalization of the asymmetric induction.