20048-06-0

Upstream product

• 108817-72-7 2,5-dimethyl-3-phenyl-4-carbomethoxy-4-isoxazoline 
• 100-52-7 benzaldehyde 
• 105-45-3 acetoacetic acid methyl ester 
• 67-56-1 methanol 
• 201230-82-2 carbon monoxide 
• 150016-65-2 (3Z)-3-iodo-4-phenylbut-3-en-2-one 
• 23326-27-4 Methyl 2-butynoate 
• 98-86-2 acetophenone 
• 3376-23-6 N-methyl-α-phenylnitrone 

Downstream Products

• 133488-55-8 6-Amino-1,4-dihydro-2-methyl-5-nitro-4-phenyl-nicotinsaeuremethylester 
• 103069-43-8 2-(2-Azido-ethoxymethyl)-6-methyl-4-phenyl-1,4-dihydro-pyridine-3,5-dicarboxylic acid 3-ethyl ester 5-methyl ester 
• 100580-07-2 6-Hydroxy-2,6-dimethyl-4-phenyl-1,4,5,6-tetrahydro-pyrimidine-5-carboxylic acid methyl ester 
• 106521-86-2 2,5-dihydro-4-methyl-2-phenyl-1,5-benzothiazepine-3-carboxylic acid, methyl ester 
• 100580-15-2 2,6-Dimethyl-4-phenyl-1,4-dihydro-pyrimidine-5-carboxylic acid methyl ester 

Relevant academic research and scientific papers

Cross-linked polystyrene-TiCl4 complex as a reusable Lewis acid catalyst for solvent-free Knoevenagel condensations of 1,3-dicarbonyl compounds with aldehydes

Cross-linked polystyrene copolymer beads with the average particle size in the range of (50–80 mesh size) were prepared by a new method, characterized and functionalized with titanium tetrachloride to afford the corresponding polystyrene?titanium tetrachloride complex in one step reaction and characterized by FT-IR, UV, TGA, DSC, XRD, SEM, BET. This polymer metal complex (PS/TiCl4) was used as a heterogeneous, recoverable, reusable Lewis acid for solvent-free Knoevenagel condensations of 1,3-diketones with aromatic aldehydes under green and mild conditions. The rate of reactions was found to decrease with an increasing percentage of crosslinking and the mesh size of the copolymer beads. This complex showed good stability and catalytic activity in the Knoevenagel reactions.

Indium(III)-catalyzed knoevenagel condensation of aldehydes and activated methylenes using acetic anhydride as a promoter

The combination of a catalytic amount of InCl3 and acetic anhydride remarkably promotes the Knoevenagel condensation of a variety of aldehydes and activated methylene compounds. This catalytic system accommodates aromatic aldehydes containing a variety of electron-donating and -withdrawing groups, heteroaromatic aldehydes, conjugate aldehydes, and aliphatic aldehydes. Central to successfully driving the condensation series is the formation of a geminal diacetate intermediate, which was generated in situ from an aldehyde and an acid anhydride with the assistance of an indium catalyst.

Synthesis of β-and β,β-substituted Morita-Baylis-Hillman adducts using a two-step protocol

The synthesis of a large number of β-and β,β-substituted keto esters was successful by the use of the Knoevenagel condensation reaction. The stereoselectivity of these reactions was improved by alteration of various substituent groups. Although there were

Reaction of aromatic aldehydes with β-dicarbonyl compounds in a catalytic system: Piperidinium acetate - 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid

Condensation of aromatic (heteroaromatic) aldehydes with 1,3-dicarbonyl compounds under the 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) ionic liquid - piperidinium acetate catalytic system (0.2 equiv. of each component) in the absence of a solvent affords, depending on the structures of the reagents, 2-arylidene derivatives of methyl acetoacetate and acetylacetone, diethyl 2,4-bis(trifluoroacetyl)-3-phenylpentanedioate, or dimethyl 2-aryl-4-hydroxy-6-oxocyclohexane-1,3-dicarboxylates. The reactions of the resulting 2-arylidene derivatives with O-methylisourea in the [Bmim][BF 4] ionic liquid produced methyl 2-methoxy-4-methyl-6- aryldihydropyrimidine-5-carboxylates and 1-(2-methoxy-4-methyl-6- phenyldihydropyrimidin-5-yl)ethanone (mixtures of 3,6- and 1,6-dihydro isomers), which were transformed into the corresponding 3,4-dihydropyrimidin-2(1H)-one derivatives.

The one-pot, multi-component construction of highly substituted tetrahydropyran-4-ones using the Maitland-Japp reaction

A one-pot, multi-component reaction for the synthesis of highly substituted tetrahydropyran-4-ones, based on the long forgotten Maitland-Japp reaction has been realised. Two different aldehydes and a derivative of a β-ketoester can be condensed regioselectively in the presence of a Lewis acid to form tetrahydropyran-4-ones in excellent yields. The diastereoselectively of the reaction was found to be dependant upon the nature of the Lewis acid and the temperature at which the reaction was carried out. This procedure was also extended to the formation of tetrahydropyran-4-ones in greater than 95% enantiomeric excess. The Royal Society of Chemistry 2005.

A two-step conversion of α,β-unsaturated ketones to their α-carbalkoxy or α-carbamoyl derivatives

Several enones are converted into their α-iodo derivatives in excellent yields and carbonylated with palladium catalysis in the presence of alcohol or amines to the α-carbonyl enones in satisfactory yields.

Stereochemical Behavior of Intermediary Compounds in the Amine-Catalyzed Knoevenagel Reaction

Treatment of the active methylene compounds and aldehydes with a catalytic amount of a secondary amine produces thermodynamically stable alkenes, and the intermediary amino compounds are isolated.The reaction involves many reversible steps, and the stereochemistry of products is determined in the elimination step from the intermediary compounds via stable planar carbanions, in which the small difference in the steric requirements of two electron-withdrawing groups is effective.Steric and electronic effects in the intermediates sometimes bring about the carbon-carbon bond fission with recovery of active methylene compounds, and these effects prevent the Knoevenagel reaction from occuring.

Peracid Oxidation of 4-Isoxazolines as a Method for the Preparation of α, β-Unsaturated Carbonyl Compounds

A study of the MCPBA peracid oxidation of a series of 4-isoxazolines has been carried out.A variety of isoxazolines were synthesized by treating nitrones with electron-deficient alkynes.An alternate approach involves dipolar cycloaddition of nitrones with activated allenes followed by a subsequent base-catalyzed isomerization of the initially formed cycloadduct.Treatment of the 5-exo-methyleneisoxazolidine derived from the reaction of N-benzylidenemethylamine N-oxide and (phenylsulfonyl)propadiene with LDA followed by γ-alkylation also produced substituted 4-isoxazolines.The peracid oxidation of the isoxazoline ring afforded α,β-unsaturated carbonyl compounds in excellent yield.Reductive cleavage of the sulfonyl group of some of the enones was achieved by initial protection of the carbonyl functionality by cyanosilylation using trimethylsilyl cyanide, and this was followed by aluminum-amalgam reduction.The cycloaddition-oxidation procedure provides an attractive route to synthesize α,β-unsaturated ketones since it avoids acidic or basic conditions.

ISOXAZOLINE OXIDATION. AN EFFICIENT METHOD FOR THE PREPARATION OF α,β-UNSATURATED CARBONYL COMPOUNDS

MCPBA peracid oxidation of Δ4-isoxazolines derived from the dipolar cycloaddition reaction of nitrones with acetylenes or allenes produces α,β-unsaturated ketones in excellent yield.