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.

Rhodium(I)-catalysed alkylation of 2-vinylpyridines with alkenes as a result of C–H bond activation

Abstract: 2-Vinylpyridines undergo regioselective β-alkylation with alkenes in the presence of a rhodium(I) complex as a catalyst to give products resulting from an anti-Markownikoff reaction. These results show the feasibility of alkylation of an alkenic position as a result of C–H bond activation. 2-(Prop-1-en-2-yl)pyridine 1 and 1-phenyl-1-(2-pyridyl)ethylene 15 react with linear terminal alkenes to give the corresponding alkylated products in high yields. Cyclic alkenes, allyl alcohol, but-3-en-1-ol and methyl vinyl ketone, however, fail to react with 1. Pent-2-ene gives the linear alkylated product in low yield. 6-Methyl-2-vinylpyridine 24 and 2-vinylpyridine 32 give the alkylated products in low yield together with their dimeric products. The alkenic C–H bond of 2-(cyclohex-1-enyl)pyridine 36 has been regioselectively alkylated. 2-(Cyclohex-1-enyl)pyridine 36 with alkenes in the presence of the RhI catalyst undergoes regiospecific alkylation at the alkenic position.

Alkylation of 4H,6H-thieno[3,4-c]furan 5,5-dioxide and its use as a 3,4-dimethylenefuran synthon in intramolecular Diels–Alder reaction

Abstract: Alkylation of 4H,6H-thieno[3,4-c]furan 5,5-dioxide (furan-annulated sulfolene)1 readily gave its 4-alkyl, 4,6-dialkyl, or 4,4-dialkyl derivatives, selectively. Attempts were made to use the appropriate derivatives as 3,4-dimethylenefuran synthons in intramolecular Diels–Alder reactions. Thus when they were heated after treatment with methyl vinyl ketone, a Diels–Alder reaction with methyl vinyl ketone on the furan moiety, desulfonylation, intramolecular Diels–Alder reaction of the resulting dienes, and retro Diels–Alder reaction occurred sequentially to afford the tricyclic fused furans 17a–c; in good yields.

GC/ITMS measurement of carbonyls and multifunctional carbonyls in PM2.5 particles emitted from motor vehicles.

Abstract: A method was developed and tested to identify and quantitate carbonyls and multifunctional carbonyls in fine particulate matter (PM 2.5 ; methylene chloride > toluene-isopropanol (2 + 1, v/v). Water provided the highest recovery for dihydroxy acetone, pyruvic acid, and hydroxy acetone, compared to methylene chloride, and toluene-isopropanol. Lowering the ultrasonication bath temperature from 0° to -8°C improved the recoveries of the less water soluble and more volatile species-methacrolein, methyl vinyl ketone, 2,3-butanedione, and tolualdehyde. The power of the method was demonstrated by identification and quantitation of carbonyls and multifunctional carbonyls in sample extracts of fine particulate matter (PM 2.5 ) collected in the Caldecott tunnel, CA. The identities of crotonaldehyde, 2,3-butanedione, glyoxal, 9H-fluoren-9-one, glycolaldehyde, glyoxylic acid, levulinic acid, and 3-hydroxybenzaldehyde were confirmed by comparing the relative retention time and mass spectra of the analyte in the sample extract with an authentic standard. Quantitation of crotonaldehyde, glyoxal, 2,3-butanedione, glyoxylic acid, and levulinic acid was accomplished. This is the first report of glyoxylic acid, levulinic acid, and 3-hydroxybenzaldheyde in PM 2.5 particles sampled in a roadway tunnel. It is also the first report of a C 10 carbonyl with the molecular formula of C 10 H 16 O 2 , a hydroxy carbonyl with the molecular formula of C 17 H 21 NO 2 , and a hydroxy or dihydroxy carbonyl with the molecular formula of C 16 H 14 O 2 or C 9 H 10 O 3 . The high-molecular weight hydroxy carbonyls, which were found only in the heavy-duty (diesel) bore, may be tracers of diesel emissions in air.

Organocatalytic Asymmetric Conjugate Addition of 3-Alkyl-Substituted Oxindoles to Vinyl Ketones

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