65749-05-5Relevant articles and documents
Selective mono-C-methylations of arylacetonitriles and arylacetates with dimethylcarbonate: A mechanistic investigation
Tundo, Pietro,Selva, Maurizio,Perosa, Alvise,Memoli, Sofia
, p. 1071 - 1077 (2007/10/03)
The very high mono-C-methylation selectivity (>99%) of arylacetic acid derivatives (ArCH2X; X = CN, CO2Me) with dimethyl carbonate (DMC) is due to a mechanism that involves consecutive methoxycarbonylation, methylation, and demethoxycarbonylation steps. Important aspects of this mechanism are clarified herein by a kinetic investigation. In the case of arylacetonitriles, at 140°C, the comparison of the rate constants of model reactions involving 2-phenyl propionitrile, phenylacetonitrile, 2-methoxycarbonylphenylacetonitrile, and 2-methyl-2-methoxy carbonylphenyl acetonitrile (compounds 1a-4a, respectively) with DMC indicates that the methylation process is the fastest and the irreversible step, which drives the overall reaction to completion. The situation is reversed for arylacetic esters, where the methylation is more difficult than the demethoxycarbonylation reaction; therefore, a higher reaction temperature is required.
Novel 5,5-disubstitutedpyrimidine-2,4,6-triones as selective MMP inhibitors
Foley, Louise H,Palermo, Robert,Dunten, Pete,Wang, Ping
, p. 969 - 972 (2007/10/03)
The 5,5-disubstitutedpyrimidine-2,4,6-triones represent a new class of MMP inhibitors showing selectivity for the gelatinases A and B, collagenase-3, and human neutrophil collagenase. The SAR presented here is in good agreement with an X-ray structure of compound 5 bound to the catalytic domain of stromelysin-1. While of the barbiturate structural class, compound 5 did not show any toxic or sedative effects.
THE ADDITION REACTION OF DIALKYL CARBONATES TO KETONES
Selva, Maurizio,Marques, Carlos Alberto,Tundo, Pietro
, p. 515 - 518 (2007/10/02)
The reaction of benzyl phenyl ketone with dimethyl carbonate gives methyl benzoate and methyl phenylacetate; diethyl carbonate gives the corresponding ethyl esters.The reaction takes place at high temperature (about 200 deg C) and in the presence of potassium carbonate as a catalyst.Other benzyl ketones react similarly.Aliphatic ketones yield a less selective addition.Accordingly, cyclohexanone with dimethyl carbonate gives dimethyl pimelate.The reaction is a retro-Claisen condensation, which occurs through the intermediate formation of the alkoxycarbonyl derivative.
Microbial asymmetric decarboxylation of fluorine-containing arylmalonic acid derivatives
Miyamoto, Kenji,Tsuchiya, Shigeo,Ohta, Hiromichi
, p. 225 - 232 (2007/10/02)
α-Methyl-α-(trifluoromethylphenyl)malonic acids have been incubated with Alcaligenes bronchisepticus to afford optically active α-arylpropionic acids.Generally, the chemical and optical yields of the reaction products were higher when the substituents on the aromatic ring were strongly electron-withdrawing.Decarboxylation of α-fluoro-α-phenylmalonic acid with the aid of the same bacterium afforded optically active α-fluoro-α-phenylacetic acid.
Enzymes in organic synthesis 50. Probing the dimensions of the large hydrophobic binding region of the active site of pig liver esterase using substituted aryl malonate substrates
Toone,Jones
, p. 1041 - 1052 (2007/10/02)
The active side model reported recently for the synthetically useful enzyme pig liver esterase (PLE) permits the structural specificity and stereoselectivity of the enzyme to be interpreted and predicted for a wide range of substrates. The specifications
The Allopolarization Principle and its Applications, IV. Substituent Effects in the Methylation of Enolate Anions
Gompper, Rudolf,Vogt, Hans-Hubert
, p. 2866 - 2883 (2007/10/02)
The ratio of O- and C-methylated products in the reaction of the sodium salts of acetophenones 1, propiophenones 3, phenylacetones 5, β-dicarbonyl compounds 12, α-cyanocarbonyl compounds 13, acetaldehyde, propionaldehyde, and diethylketone with dimethyl sulfate, methyl iodide, and trimethyl phosphate in HMPTA has been determined with regard to the effect of substituents.In some cases the influence of solvents, concentration and temperature has also been studied.