504-85-8Relevant articles and documents
Palladium-Catalyzed Low Pressure Carbonylation of Allylic Alcohols by Catalytic Anhydride Activation
Schelwies, Mathias,Paciello, Rocco,Pelzer, Ralf,Siegel, Wolfgang,Breuer, Michael
supporting information, p. 9263 - 9266 (2021/05/27)
A direct carbonylation of allylic alcohols has been realized for the first time with high catalyst activity at low pressure of CO (10 bar). The procedure is described in detail for the carbonylation of E-nerolidol, an important step in a new BASF-route to (?)-ambrox. Key to high activities in the allylic alcohol carbonylation is the finding that catalytic amounts of carboxylic anhydride activate the substrate and are constantly regenerated with carbon monoxide under the reaction conditions. The identified reaction conditions are transferrable to other substrates as well.
Oxidation of isohumulones induces the formation of carboxylic acids by hydrolytic cleavage
Rakete, Stefan,Berger, Robert,Boehme, Steffi,Glomb, Marcus A.
, p. 7541 - 7549 (2014/08/18)
The degradation of isohumulones in mechanistic experiments was investigated. Incubation of trans-isohumulone in the presence of l-proline led to the formation of carboxylic acids and their corresponding proline amides. In the context of isohumulones unknown amides were verified first in model incubations and then in beer for the first time by comparison with authentic reference standards via LC-MS analyses. Carboxylic acids and amides were formed preferably under oxidative conditions and increasing pH. Stable isotope experiments excluded the incorporation of molecular oxygen into carboxylic acids, strongly indicating a hydrolytic mechanism via β-dicarbonyl cleavage. The proposed mechanism includes oxidation and thereby incorporation of molecular oxygen to the isohumulone ring structure followed by hydrolytic cleavage leading to acids and amides.
Oxidation of isohumulones induces the formation of carboxylic acids by hydrolytic cleavage
Rakete, Stefan,Berger, Robert,B?hme, Steffi,Glomb, Marcus A.
, p. 7541 - 7549 (2015/04/22)
The degradation of isohumulones in mechanistic experiments was investigated. Incubation of trans-isohumulone in the presence of l-proline led to the formation of carboxylic acids and their corresponding proline amides. In the context of isohumulones unknown amides were verified first in model incubations and then in beer for the first time by comparison with authentic reference standards via LC-MS analyses. Carboxylic acids and amides were formed preferably under oxidative conditions and increasing pH. Stable isotope experiments excluded the incorporation of molecular oxygen into carboxylic acids, strongly indicating a hydrolytic mechanism via β-dicarbonyl cleavage. The proposed mechanism includes oxidation and thereby incorporation of molecular oxygen to the isohumulone ring structure followed by hydrolytic cleavage leading to acids and amides.
Method for regio- and stereoselective synthesis of (E)-Β,γ- unsaturated acids from aldehydes under solvent-free conditions
Zhang, Shi-Jie,Hu, Wei-Xiao
experimental part, p. 3093 - 3100 (2010/12/19)
Synthesis of (E)-β,-γunsaturated acids from aldehydes with malonic acid has been explored under solvent-free conditions. The modified Knoevenagel condensation reaction with N-methyl morpholine (NMM) as catalyst exhibits highly β,-γ regioselectivity and exclusively E-stereoselectivity. A mechanism accounting for both regio- and stereoselectivity has been proposed and preliminarily studied. Copyright Taylor & Francis Group, LLC.
SiO2 catalysed expedient synthesis of [E]-3-alkenoic acids in dry media
Kumar, H.M. Sampath,Reddy, B.V. Subba,Reddy, E. Jagan,Yadav
, p. 2401 - 2404 (2007/10/03)
Aliphatic aldehydes with α-hydrogens and malonic acid undergo decarboxylative condensation on the surface of SiO2 when subjected to microwave irradiation generating βγ-unsaturated acids in high yields.
Hydrocarboxylation of isoprene catalyzed by iodo-carbonylrhodium derivatives. Spectroscopic evidence for participation of H+...Rh(CO)2I2- tight ion pairs and cis-Rh(CO)2(H2O)I in catalysis
Garlaschelli, Luigi,Marchionna, Mario,Iapalucci, Maria Carmela,Longoni, Giuliano
, p. 457 - 468 (2007/10/02)
Hydrocarboxylation of isoprene catalyzed by iodocarbonylrhodium derivatives is described.Either 4-methyl-3-pentenoic (pyroterebic) acid or its lactone derivative (γ,γ-dimethyl-γ-butyrolactone) can be selectively produced in high yield depending on the experimental conditions.Spectroscopic evidence indicates the possibe partcipation of H+...Rh(CO)2I- tight ion pairs and/or cisRh(CO)2(H2O)I in the catalysis.The identification of these two new species is based on spectroscopic investigation of the interconversion reactions between solvent-separated +- ions and 2 (X=Cl, I).
MODIFIED KNOEVENAGEL CONDENSATIONS. SYNTHESIS OF (E)-3-ALKENOIC ACIDS.
Ragoussis, Nikitas
, p. 93 - 96 (2007/10/02)
Condensation of aliphatic aldehydes with a three molar excess of malonic acid and 0.001 mole piperidinium acetate in refluxing xylene, with continuous removal of the water formed, gave almost exclusively (E)-3-alkenoic acids, in good yield (60-85percent) and of high stereochemical purity (95-99percent).
STEREOCHEMISTRY OF THE ADDITION OF SECONDARY AMINES TO VINYLACETYLENIC YNAMINES
Tolchinskii, S. E.,Maretina, I. A.
, p. 1034 - 1038 (2007/10/02)
The addition of allylic and propargyl secondary amines and aliphatic-aromatic amines to 1-dialkylamino-3-penten-1-ynes under acid catalysis conditions proceeds regioselectively at the acetylenic bond and stereospecifically as a cis process.
Studies in Decarboxylation. Part 13. The Incursion of a Stepwise Mechanism in the Gas-phase Decarboxylation of Cyclopropylacetic Acids
Bigley, David B.,Fetter, Clive L.,Clarke, Michael J.
, p. 553 - 556 (2007/10/02)
The cyclopropylacetic acids (I)-(IV) have been decarboxylated in the temperature range 720-820 K.It is demonstrated that at 725 K, 2',2'-dimethylcyclopropylacetic acid is decarboxylated by both concerted and stepwise mechanisms.The latter is favoured by higher temperature.Cyclopropylacetic acid is decarboxylated by the concerted mechanism at 725 K, but also exhibits the stepwise mechanism at higher temperature.
