79120-96-0Relevant academic research and scientific papers
On the intermolecular interaction of N-benzylquininium chloride or quinine with some carbonyl group containing compounds
Avila, Thais C.,Reginato, Marcelo M.,Di Vitta, Cláudio,Ducati, Lucas C.,Andrade, Leandro H.,Marzorati, Liliana
supporting information, p. 2152 - 2157 (2016/05/02)
Interactions between N-benzylquininium chloride (Quibec) and some carbonyl group containing compounds were investigated using 1H NMR and theoretical calculations. Results highlight the importance of the hydrogen bonding between the Quibec C-9 h
Synthesis of Chiral Pyrazoles: A 1,3-Dipolar Cycloaddition/[1,5] Sigmatropic Rearrangement with Stereoretentive Migration of a Stereogenic Group
Pérez-Aguilar, M. Carmen,Valdés, Carlos
, p. 13729 - 13733 (2015/11/11)
The reactions between terminal alkynes and α-chiral tosylhydrazones lead to the obtention of chiral pyrazoles with a stereogenic group directly attached at a nitrogen atom. The cascade reaction includes decomposition of the hydrazone into a diazocompound, 1,3-dipolar cycloaddition of the diazo compound with the alkyne, and [1,5] sigmatropic rearrangement with migration of the stereogenic group. This strategy has been successfully applied to the synthesis of structurally diverse chiral pyrazoles through α-chiral tosylhydrazones, obtained from α-phenylpropionic acid, α-amino acids, and 2-methoxycyclohexanone. Notably, the stereoretention of the [1,5] sigmatropic rearrangements represent very rare examples of this stereospecific transformation.
Catalytic enantioselective protoboration of disubstituted allenes. Access to alkenylboron compounds in high enantiomeric purity
Jang, Hwanjong,Jung, Byunghyuck,Hoveyda, Amir H.
supporting information, p. 4658 - 4661 (2015/02/19)
Proto-boryl additions to 1,1-disubstituted allenes in the presence of 1.0-5.0 mol % of chiral NHC-Cu complexes, B2(pin)2, and t-BuOH proceed to afford alkenyl-B(pin) products in up to 98% yield, >98:2 site selectivity, and 98:2 er. T
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.
AuBr3-catalyzed thiooxime-to-carbonyl conversion: From chiral aliphatic nitro compounds to ketones without racemization
Bures, Jordi,Lsart, Carles,Vllarrasa, Jaume
supporting information; experimental part, p. 4414 - 4417 (2009/12/24)
A new variant of the NO2-to-CO transformation (the Nef reaction) that occurs at room temperature under neutral conditions is uncovered. After the conversion of secondary nitroalkanes to phenylsulfenylketlmines, these thlooximes are hydrolyzed quantitatively In situ, In THF-H2O at pH 7, by addition of AuBr3 (but not with other MXn!). Adducts arising from asymmetric nitro-Mlchael and nltro-aldol reactions afford 1,4-dlketones and a-alkoxy ketones, respectively, with full retention of the configuration of the stereocenters a to the CHNO2/C=N-SPh/C=o groups.
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.
Selective Baeyer-Villiger oxidation of racemic ketones in aqueous-organic media catalyzed by phenylacetone monooxygenase
Rodriguez, Cristina,de Gonzalo, Gonzalo,Torres Pazmino, Daniel E.,Fraaije, Marco W.,Gotor, Vicente
, p. 197 - 203 (2008/09/18)
The enantioselective kinetic resolution of a set of racemic substituted 3-phenylbutan-2-ones employing phenylacetone monooxygenase (PAMO) in non-conventional media was performed. The studies have revealed the effects of a range of solvents on the biocatalytic properties of the biocatalyst. Also, the enzymatic oxidation of α-acetylphenylacetonitrile was performed using organic cosolvents. This has resulted in a dynamic kinetic resolution of this cyanoketone yielding enantiopure (R)-2-acetoxyphenylacetonitrile with moderate yields depending on the reaction conditions employed.
Enantioselective kinetic resolution of 3-phenyl-2-ketones using Baeyer-Villiger monooxygenases
Geitner, Kristian,Kirschner, Anett,Rehdorf, Jessica,Schmidt, Marlen,Mihovilovic, Marko D.,Bornscheuer, Uwe T.
, p. 892 - 895 (2008/02/08)
The enantioselective kinetic resolution of two 3-phenyl-2-ketones using four different Baeyer-Villiger monooxygenases (BVMO) expressed recombinantly in Escherichia coli was studied. The highest enantioselectivity (E = 82) was achieved for 3-phenyl-2-butanone using a BVMO originating from Pseudomonas fluorescens. A BVMO from Pseudomonas putida showed an opposite (R)-enantiopreference and E = 12.
Enzymatic kinetic resolution of racemic ketones catalyzed by Baeyer-Villiger monooxygenases
Rodriguez, Cristina,de Gonzalo, Gonzalo,Fraaije, Marco W.,Gotor, Vicente
, p. 1338 - 1344 (2008/02/09)
A set of racemic cyclic and linear ketones, as well as 2-phenylpropionaldehyde, were tested as substrates in the enzymatic Baeyer-Villiger oxidation catalyzed by two Baeyer-Villiger monooxygenases: phenylacetone monooxygenase (PAMO) and 4-hydroxyacetophenone monooxygenase (HAPMO). Excellent enantioselectivites (E > 200) can be obtained in the kinetic resolution processes depending on the substrate structure and the reaction conditions. The parameters affecting the biocatalytic properties of these enzymes were also studied, in order to establish a deeper understanding of these novel biocatalysts.
Catalysed asymmetric protonation of simple linear keto-enolic species a route to chiral α-arylpropionic acids
Roy, Olivier,Riahi, Abdelkhalek,Henin, Francoise,Muzart, Jacques
, p. 3986 - 3994 (2007/10/03)
The reaction cascade consisting of deprotection/decarboxylation/asymmetric protonation of enolic species, starting from open-chain benzyl β-oxo esters, has been studied. When carried out in the presence of catalytic amounts of cinchonine, the reaction gave optically active α-aryl ketones with up to 75% ee. Enantio-enriched (S)-3-phenyl-2-butanone can be converted into 2-phenylpropionic acid without racemisation. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
