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Diethyl Acetal (diethyl + acetal)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

Acrolein Diethyl Acetal: A Three-Carbon Homologating Reagent for the Synthesis of ,-Arylpropanoates and Cinnamaldehydes by Heck Reaction Catalyzed by a Kaiser Oxime Resin Derived Palladacycle

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 18 2008
Emilio Alacid
Abstract A polymer palladacycle derived from Kaiser oxime resin was used as a source of palladium(0) in the chemoselective Heck reaction of acrolein diethyl acetal with aryl halides under ligand-free conditions. The use of typical Heck conditions afforded 3-arylpropionic esters, and the process can be directed to the synthesis of cinnamaldehydes under Cacchi conditions. These processes take place with rather low loading of the catalyst, which can be recovered by simple filtration and reused for at least five runs without competitive dehalogenation. This is the first time that a supported palladium complex has been reused under Cacchi conditions. ICP-OES analyses of the Pd content of the crude products in both transformations indicated lower leaching for the esters than for the aldehydes in the range up to 0.08 ppm for the esters and 0.8 ppm for the aldehydes.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

Reactions of 1,2-Bis(trimethylsilyloxy)cycloalkenes with the Diethyl Acetals of Aldehydes.

CHEMINFORM, Issue 20 2006
Fuye Gao
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

Palladium-Catalyzed C2 or C5 Direct Arylation of 3-Formylthiophene Derivatives with Aryl Bromides

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 4 2010
Jia Jia Dong
Abstract The system Pd(OAc)2/dppb was found to be an efficient catalyst precursor for the direct arylation of 3-formylthiophene derivatives. When using 3-formylthiophene, the 2-arylated thiophenes were obtained with regioselectivities of 76,86,%, whereas the arylation of 3-formylthiophene diethyl acetal gave the 5-arylated thiophenes with regioselectivities of 64,88,%. These reactions were performed by using only 0.1 mol-% of the catalyst. Moreover, this procedure has been found to be tolerant to a variety of functional groups on the aryl bromide such as formyl, propionyl, benzoyl, nitrile, or nitro. [source]

Acrolein Diethyl Acetal: A Three-Carbon Homologating Reagent for the Synthesis of ,-Arylpropanoates and Cinnamaldehydes by Heck Reaction Catalyzed by a Kaiser Oxime Resin Derived Palladacycle

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 18 2008
Emilio Alacid
Abstract A polymer palladacycle derived from Kaiser oxime resin was used as a source of palladium(0) in the chemoselective Heck reaction of acrolein diethyl acetal with aryl halides under ligand-free conditions. The use of typical Heck conditions afforded 3-arylpropionic esters, and the process can be directed to the synthesis of cinnamaldehydes under Cacchi conditions. These processes take place with rather low loading of the catalyst, which can be recovered by simple filtration and reused for at least five runs without competitive dehalogenation. This is the first time that a supported palladium complex has been reused under Cacchi conditions. ICP-OES analyses of the Pd content of the crude products in both transformations indicated lower leaching for the esters than for the aldehydes in the range up to 0.08 ppm for the esters and 0.8 ppm for the aldehydes.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

A New Approach to the Synthesis of N,N -Dialkyladenine Derivatives

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 29 2007
M. José Alves
Abstract N,N- Dialkyladenine derivatives were prepared by two different reaction sequences starting from 5-amino-4-cyanoformimidoylimidazoles. When these imidazoles were treated with dimethylformamide diethyl acetal, a 5-aminomethyleneamino-4-cyanoformimidoylimidazole was isolated and evolved to the N,N- dialkyladenine in the presence of a secondary alkylamine. The same purine structure was isolated when the 5-amino-4-cyanoformimidoylimidazole was first treated with a secondary amine to give a stable 4-amidino-5-aminoimidazole. The desired product was generated when the 4-amidino-5-aminoimidazole was combined with dimethylformamide diethyl acetal, at room temperature. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]

Novel Building Blocks: 1-Aryl-2-chloro-1-ethoxyethenes , Preparations and Transformations,

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 3 2007
Mitsuhiro Yoshimatsu
Abstract We described here a simple method for the preparation of 1-aryl-2-chloro-1-ethoxyethenes 2a,u, which are prodrugs for Alzheimer's disease, by the reaction of dichloroacetaldehyde diethyl acetal with various aryl and alkenyllithium compounds in high yields. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]

The mechanisms of the homogeneous, unimolecular, elimination kinetics of several , -substituted diethyl acetals in the gas-phase

JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 9 2010
José R. Mora
Abstract The rates of gas-phase elimination of several , -substituted diethyl acetals have been determined in a static system and seasoned with allyl bromide. The reactions, inhibited with toluene, are homogeneous, unimolecular, and follow first-order law kinetics. These elimination processes involve two parallel reactions. The first parallel reaction yields ethanol and the corresponding ethyl vinyl ether. The latter product is an unstable intermediate and further decomposes to ethylene and the corresponding substituted aldehyde. The second parallel reaction gives ethane and the corresponding ethyl ester. The kinetics has been measured over the temperature range of 370,441,°C and pressure range of 23,160,torr. The rate coefficients are given by the following Arrhenius equations: The differences in the rates of ethanol formation may be attributed to electronic transmission of the , -substituent. The comparative kinetic and thermodynamic parameters of the parallel reactions suggest two different concerted polar four-membered cyclic transition state types of mechanisms. Copyright © 2010 John Wiley & Sons, Ltd. [source]