Methyl vinyl ketone

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

aza-Baylis−Hillman Reaction

Abstract: 2.3.3. Fluorinated Imines 7 2.3.4. Arylimino Acetates 8 2.3.5. In Situ Generated Iminium Ions 8 2.4. -Substituted Michael Acceptors 8 2.5. Formation of Unexpected Products 10 2.5.1. Reaction with Cyclic Enones 11 2.5.2. Reaction with Vinyl Ketones 11 2.5.3. Reaction with Acrolein 12 2.5.4. Reaction with Activated Allenes and Alkynes 12 2.5.5. Reaction of Salicyl N-Tosylimines 12 3. Stereoselective Synthesis 13 3.1. Use of Chiral Aldehydes 13 3.2. Use of Chiral Bases 13 3.3. Use of Chiral Phosphines 16 3.4. Use of a Chiral Sulfide 18 3.5. Use of an Organocatalyst Derived from BINOL 18 3.6. Use of a Chiral Ligand Derived from Thiourea 18 3.7. Use of Chiral Ionic Liquids 18 4. Alternative Access Pathways to -Aminocarbonyl Compounds 18

Organocatalysed asymmetric Mannich reactions.

Abstract: The asymmetric Mannich reaction ranks among the most potent enantioselective and diastereoselective C–C-bond forming reactions. In recent years, organocatalysed versions of asymmetric Mannich processes have been increasingly reported and used in a rapidly growing number of applications. This tutorial review provides an overview of the recent history of the asymmetric organocatalysed Mannich reaction, including scope and limitations, and application of different catalyst systems.

A product study of the gas-phase reaction of Isoprene with the OH radical in the presence of NOx

Abstract: The gas-phase reaction of isoprene with the OH radical, in the resence of NOx, was investigated at 298 ± 2 K and atmospheric pressure of air by long path length FT-IR spectroscopy. The primary products identified and their formation yields were: methacrolein, 0.21 ± 0.05; methyl vinyl ketone, 0.29 ± 0.07; and HCHO, with the observed yield being consistent with the sum of the methacrolein and methyl vinyl ketone yields. Combined with the previously reported yield of 0.044 ± 0.006 for 3-methylfuran, these products accounted for 55 ± 9% of the isoprene which reacted. Under conditions where the dark reaction of isoprene with NO2is not significant, the balance of the isoprene consumed could possibly be accounted for by the “organic nitrates” and “other carbonyl compounds” formed in estimated overall yields of ca. 12% and ca. 25%, respectively.

Chiral phosphine lewis bases catalyzed asymmetric aza-Baylis-Hillman reaction of N-sulfonated imines with activated olefins.

Abstract: In the aza-Baylis-Hillman reaction of N-sulfonated imines (N-arylmethylidene-4-methylbenzenesulfonamides and others) with methyl vinyl ketone, ethyl vinyl ketone, and acrolein, we found that, in the presence of a catalytic amount of chiral phosphine Lewis base such as (R)-2'-diphenylphosphanyl-[1,1']binaphthalenyl-2-ol LB1 (10 mol %) and molecular sieve 4A, the corresponding aza-Baylis-Hillman adducts could be obtained in good yields with good to high ee (70-95% ee) at low temperature (approximately -30 to -20 degrees C) or at room temperature in THF, respectively. In CH2Cl2 upon heating at 40 degrees C, the aza-Baylis-Hillman reaction of N-sulfonated imines with phenyl acrylate or naphthyl acrylate gave the adducts in good to high yields (60-97%) with moderate ee (52-77%). The mechanistic insight has been investigated by 31P and 1H NMR spectroscopic measurements. The key enolate intermediate, which has been stabilized by intramolecular hydrogen bonding, has been observed by 31P and 1H NMR spectroscopy. An effective bifunctional Lewis base and Bronsted acid phosphine Lewis base system has been disclosed in this catalytic, asymmetric aza-Baylis-Hillman reaction.

Highly stereospecific palladium-catalysed vinylation of vinylic halides under solid-liquid phase transfer conditions.

Abstract: (E,E) and (E,Z) conjugated dienoates, dienones and dienals are obtained with high stereospecificity (⩾95%) and in high yields from the corresponding (E) and (Z) vinylic halides and vinylic substrates (methyl acrylate, methyl vinyl ketone or acrolein), in the presence of potassium carbonate, tetrabutylammonium chloride and a catalytic amount of palladium acetate, in N,N-dimethylformamide at room temperature.