172424-26-9Relevant articles and documents
Stereochemistry and mechanism of enzymatic and non-enzymatic hydrolysis of benzylic sec-sulfate esters
Toesch, Michael,Schober, Markus,Breinbauer, Rolf,Faber, Kurt
supporting information, p. 3930 - 3934 (2014/06/24)
The substrate scope of inverting alkylsulfatase Pisa1 was extended towards benzylic sec-sulfate esters by suppression of competing non-enzymatic autohydrolysis by addition of dimethyl sulfoxide as co-solvent. Detailed investigation of the mechanism of autohydrolysis in 18O-labeled buffer by using an enantiopure sec-benzylic sulfate ester as substrate revealed that from the three possible pathways (i) inverting SN2-type nucleophilic attack of [OH-] at the benzylic carbon represents the major pathway, whereas (ii) SN1-type formation of a planar benzylic carbenium ion leading to racemization was a minor event, and (iii) Retaining SN2-type nucleophilic attack at sulfur took place at the limits of detection. The data obtained are interpreted by analysis of Hammett constants of meta substituents. The enzymatic hydrolysis of benzylic sec-sulfate esters by alkylsulfatase Pisa1 proceeded with clean inversion of configuration and with excellent stereoselectivities when the competing non-enzymatic hydrolysis was suppressed by addition of dimethyl sulfoxide as co-solvent. Copyright
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
experimental part, 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.
