19759-22-9Relevant articles and documents
BVMO-catalysed dynamic kinetic resolution of racemic benzyl ketones in the presence of anion exchange resins
Rodriguez, Cristina,De Gonzalo, Gonzalo,Rioz-Martinez, Ana,Torres Pazmino, Daniel E.,Fraaije, Marco W.,Gotor, Vicente
body text, p. 1121 - 1125 (2010/06/20)
4-Hydroxyacetophenone monooxygenase from Pseudomonas fluorescens ACB was employed in the presence of a weak anion exchange resin to perform dynamic kinetic resolutions of racemic benzyl ketones with high conversions and good optical purities. Different parameters that affect to the efficiency of the enzymatic Baeyer-Villiger oxidation and racemisation were analyzed in order to optimize the activity and selectivity of the biocatalytic system. The Royal Society of Chemistry.
Baeyer-Villiger monooxygenase-catalyzed kinetic resolution of racemic α-alkyl benzyl ketones: enzymatic synthesis of α-alkyl benzylketones and α-alkyl benzylesters
Rodriguez, Cristina,Gonzalo, Gonzalo de,Torres Pazmino, Daniel E.,Fraaije, Marco W.,Gotor, Vicente
experimental part, p. 1168 - 1173 (2009/10/02)
The application of three BVMOs for the enantioselective oxidation of 3-phenylbutan-2-ones with different substituents in the aromatic moiety is described. By choosing the appropriate biocatalyst and substrate combination, chiral ketones and esters can be obtained with excellent enantiopurities. This methodology could also be applied to the resolution of racemic α-alkyl benzylketones with longer alkyl chains as well as with two substituted α-substituted benzylacetones. A kinetic analysis revealed that the BVMOs studied effectively convert all tested compounds showing that the enzymes are tolerant towards the substrate structure while being highly enantioselective. These properties render BVMOs as valuable biocatalysts for the preparation of compounds with high interest in organic synthesis.
Asymmetric transesterification of secondary alcohols catalyzed by feruloyl esterase from Humicola insolens
Hatzakis, Nikos S.,Smonou, Ioulia
, p. 325 - 337 (2007/10/03)
A new asymmetric transesterification of secondary alcohols catalyzed by feruloyl esterase from Humicola insolens has been found. Although alcohols are not the natural substrates for this enzyme, a high R enantioselectivity was observed. Stereochemical studies showed that variations in substrate structure lead to strong variations in enantioselectivity. The highest enantioselectivities are obtained when the β-carbon of the secondary alcohol is tertiary or quaternary.
Entrapment of Pseudomonas cepacia lipase with peracetylated β-cyclodextrin in sol-gel: Application to the kinetic resolution of secondary alcohols
Ghanem, Ashraf,Schurig, Volker
, p. 2547 - 2555 (2007/10/03)
Co-lyophilized Pseudomonas cepacia lipase with peracetylated β-cyclodextrin was immobilized by the sol-gel process. The gel-entrapped lipase/cyclodextrin was prepared by the hydrolysis of methyltrimethoxysilane (MTMS) in the presence of the co-lyophilized lipase with peracetylated β-cyclodextrin prepared with different weight ratios (enzyme to CD). This type of enzyme preparation was subsequently used in the kinetic resolution of a set of secondary alcohols using isopropenyl acetate as an innocuous acyl donor in toluene as the organic medium. The resulting chiral alcohols (substrate) and the corresponding acetates (product) were baseline separated in one analysis without derivatization using gas chromatography on a new chiral stationary phase (CSP) Chirasil-β-Dex containing an undecamethylene spacer (C11-Chirasil-Dex).
ESTERIFICACION DE DERIVADOS DE ESTIRENO CON ACIDO ACETICO EN PRESENCIA DE ACIDO PERCLORICO COMO CATALIZADOR
Cuesta, Pedro J. Martinez de la,Martinez, Eloisa Rus,Sosa, Rafael Palomino,Perez, Fuensanta I. Palomino
, p. 26 - 31 (2007/10/02)
The present work is focused to develop the production of esters from derivatives of styrene by acetic acid using perchloric acid as a catalyst.The kinetics of the reaction was studied and analysis of the variables was carried out.Key words: Esterification, styrene, perchloric, acid, acetic acid.
