51503-03-8

Upstream product

• 17795-68-5 (C₄H₉)3SnOC(t-C₄H₉)CH₂ 
• 614-47-1 1,3-diphenyl-propen-3-one 
• 538-44-3 (E)-benzylidenepinacolone 
• 72657-90-0 Propiophenone lithium enolate 
• 72658-01-6 lithiopropiophenone 
• 613-91-2 acetophenone oxime 
• 75-97-8 3,3-dimethyl-butan-2-one 
• 94-41-7 benzalacetophenone 
• 538-44-3 4,4-dimethyl-1-phenyl-1-penten-3-one 
• 98-86-2 acetophenone 

Relevant academic research and scientific papers

Michael addition of stannyl ketone enolate to α,β-unsaturated esters catalyzed by tetrabutylammonium bromide and an ab initio theoretical study of the reaction course

Michael addition of stannyl ketone enolates to α,β-unsaturated esters was accomplished in the presence of a catalytic amount of tetrabutylammonium bromide (Bu4NBr). Other typical systems using lithium enolate or silyl enolate with catalysts (TiCl4 or Bu4NF) failed to give the desired products. The bromide anion from Bu4NBr coordinates to the tin center in enolate to accelerate the conjugate addition where a five-coordinated tin species was generated. The coordination of the bromide anion significantly raises the HOMO level of tin enolate and enhances its nucleophilicity. The conjugate addition provides the intermediate Michael adduct, which has an ester enolate moiety, and the adduct immediately transforms to α-stannyl γ-ketoester by keto - enol tautomerization. This step contributes to the stabilization of the product system and leads to a thermodynamically favorable reaction course. An ab initio calculation reveals that the activation energy in the reaction using the bromide anion is lower than that of the reaction without using it. The transition state in either reaction course has a linear structure, not a cyclic one. This system can be applied to a variety of tin enolates and α,β-unsaturated carbonyls involving enoates, enones, and unsaturated amides.

Samarium(III) tris(2,6-di-tert-butyl-4-methylphenoxide): Preparation, properties, and catalytic activity in the Michael type reaction

Samarium(III) tris(2,6-di-tert-butyl-4-methylphenoxide) (1), which is a highly coordinatively unsaturated complex, was prepared by the reaction of samarium(III) iodide with sodium 2,6-di-tert-butyl-4-methylphenoxide, and the crystal structure of its aceto

Stereochemistry of the Michael Addition of Ester and Ketone Enolates to α,β-Unsaturated Ketones

The stereo- and regiochemistry of addition of the enolates of ketones and esters to α,β-unsaturated ketones has been studied.There is a strong correlation between the enolate geometry and adduct stereostructure, with E enolates forming syn products and Z

A Novel Formation of Phenyl-Substituted Pyridines by the Reaction of N-(Diphenylphosphinyl)-1-azaallyl Anions with α,β-Unsaturated Carbonyl Compounds. A New Synthetic Equivalent of Primary Vinylamines

The N-phosphinyl-1-azaallyl anions, which were derived from the corresponding imine or enamine reacted with α,β-unsaturated carbonyl compounds to afford phenyl-substituted pyridines along with 1-propanone and 1,5-pentanedione derivatives.A plausible mechanism involving a sequence of Michael addition and intramolecular aza-Horner-Wittig reaction is described, and the 1-azaallyl anions were found to behave as a synthetic equivalent of primary vinylamines.

ADDITION REGIOSELECTIVE D'ENOLATES DE CETONES AUX α-ENONES INFLUENCE DES FACTEURS STERIQUES SUR L'ORIENTATION ET LA REVERSIBILITE DES REACTIONS

Regio and stereochemistry in the addition of preformed magnesium and lithium ketone enolates (1 to 8) to α-enones (10 and 11) have been examined.When the substitution degree of the enolate is increased the formation of δ-diketone is favoured; neverthless a good efficiency in the synthesis of the γ-ethylenic β-ketols (1-2 addition) is obtained via bromomagnesium enolates (EMgX) under kinetic conditions.Lithium enolate (ELi) and, chiefly magnesium bienolate (E2Mg) give preferentially the Michael addition.Reversibility from 1-2 to 1-4 addition is commonly observed but the stereochemistry, if any, of the diastereoisomeric δ-diketones may be quite different when using EMgBr or E2Mg as starting enolates.