30262-98-7Relevant academic research and scientific papers
A new reaction between E-cinnamaldehyde and phenyllithium. Mechanistic studies
Nudelman, Norma S.,Schulz, Hernan G.
, p. 2761 - 2767 (1999)
The reaction of phenyllithium (in excess) with E-cinnamaldehyde gives a surprising tandem addition β-alkylation, which can be successfully used for the synthesis of substituted dihydrochalcones. The mechanism by which these unexpected reactions could occur is unknown and experimental and theoretical studies were carried out as a contribution to its understanding. The observed concentration effects, the surprising changes in the product distribution upon changes in the reaction conditions, the haptomeric structure of the calculated intermediates and the calculated activation energies are consistent with a reaction pathway in which dimeric phenyllithium attacks the E-cinnamaldehyde without prior deaggregation. Solvated structures were also calculated using a "dielectric continuum" model for solvent effects.
Platinum-catalyzed generation of silylenes from hydrodisilanes and their addition to α,β-unsaturated ketones
Okamoto, Kazuhiro,Hayashi, Tamio
, p. 108 - 109 (2008/09/20)
The reaction of hydrodisilanes with α,β-unsaturated ketones in the presence of a platinum catalyst gave high yields of oxasilacyclopentenes, which are probably formed by the addition of silylenes to the enones. Treatment of the oxasilacyclopentenes with methyllimium followed by hydrolysis gave the corresponding β-silyl ketones. Copyright
Tandem addition β-lithiation - Alkylation sequence on α,β-unsaturated aldehydes
Nudelman,Garcia
, p. 1387 - 1394 (2007/10/03)
A tandem reaction between (E)-cinnamaldehyde, 1a, and phenyllithium affording β-substituted dihydrochalcones was recently reported. NMR spectroscopic studies on the reaction mixture, as well as isotopic exchange reactions and trapping of two intermediates, provide clues on the several mechanistic steps of this new reaction. Extended studies revealed that β-alkyl-substituted α,β-unsaturated aldehydes and aliphatic lithium reagents did not afford good yields of the tandem reaction products, while aromatic lithium reagents gave good results. The aggregation features of the aryllithium reagents and the extended charged delocalization effects are considered to promote β-selectivity. This approach provides a convenient route for the synthesis of a wide variety of β-alkyl-substituted dihydrochalcones.
Synthesis of β-silylated olefins from α,β-unsaturated aldehydes and ketones
Bolourtchian,Mojtahedi,Saidi
, p. 590 - 591 (2007/10/03)
α,β-Unsaturated aldehydes and ketones such as phorone, benzalacetone, benzalacetophenone, 4-(2-furyl)-3-buten-4-one and β-ionone, react with TMS-Cl in the presence of Li in THF to give conjugated β-silylated enoxysilanes. Hydrolysis of this compounds in a
Direct Michael-Type Addition of Si-Groups to α,β-unsaturated β-Aryl-Substituted Enones with R3SiCl/Bu2Cu(CN)Li2
Amberg, Willi,Seebach, Dieter
, p. 2439 - 2444 (2007/10/02)
(E)-5-Benzylidene-2-tert-butyl-6-methyl-1,3-dioxan-4-one (1) undergoes conjugative silylation (Me3Si, Et3Si, tBuMe2Si, Me2PhSi, products 2-5) with the reagent specified in the title.The reaction is highly diastereoselective, with formal anti addition of R
Barium Permanganate, Ba(MnO4)2, a versatile and mild oxidizing agent for use under aprotic and non-aqueous conditions
Firouzabadi,Seddighi,Mottaghineiad,Bolourchian
, p. 6869 - 6878 (2007/10/02)
Barium Permanganate is an easily prepared, stable, and a versatile oxidation reagent. With this reagent different types of primary and secondary hydroxy compounds are converted to their carbonyl derivatives. Aldehydes could be transformed to their carboxylic acids. Benzylic chloride and bromides are converted to their aldehydes and carboxylic acids. Semicarbazide and 2,4-dinitrophenylhydrazine derivatives of benzylic carbonyl compounds undergo carbon-nitrogen bond cleavage selectively and yield the expected carbonyl compounds. p-Hydroquinone is converted to p-benzoguinone and aromatic amines to their azo compounds. Anthracene and phenanthrene produce their 9,10-quinones. Diphenyl acetylene and trans stilbene give benzil, and styrene produces benzaldehyde. Selective oxidations of secondary benzylic carbon-hydrogen bonds occur and the corres- ponding carbonyl compounds are produced in good yields.
