نتایج جستجو برای: β-ketoesters
تعداد نتایج: 177597 فیلتر نتایج به سال:
This study presents the bioreduction of six β-ketoesters by whole cells of Kluyveromyces marxianus and molecular investigation of a series of 13 β-ketoesters by hologram quantitative structure-activity relationship (HQSAR) in order to relate with conversion and enantiomeric excess of β-stereogenic-hydroxyesters obtained by the same methodology. Four of these were obtained as (R)-configuration a...
Sequential Wolff rearrangement of α-diazo-β-ketoesters followed by trapping of the ketene intermediates with enol ethers generated a variety of γ,δ-unsaturated β-ketoesters. This method involves a novel thermal cascade reaction and allows the synthesis of γ,δ-unsaturated β-ketoesters with trans-stereochemistry under catalyst-free conditions. The synthesized compounds were further transformed in...
Abstract Selective syntheses of coumarin and benzofuran derivatives were achieved via HClO4-mediated intermolecular annulation using phenols α-methoxy-β-ketoesters. Coumarins are formed under dehydrated conditions, whereas benzofurans in the presence water. In synthetic process benzofurans, α-methoxy-β-ketoesters converted into α-methoxyacetophenones, methoxy group is an important element annul...
This paper describes step-economic iodine-mediated construction of functionalized arylazopyrazoles in the presence of catalytic AgNO3 starting from simple β-ketoesters and two equivalents of arylhydrazines. This cascade reaction includes in situα-iodination of β-ketoesters, pyrazol-3-one formation, substitution with a nitrogen nucleophile, and oxidation/aromatization.
A highly robust and productive self-sufficient heterogeneous biocatalysts to asymmetrically reduce β-ketoesters.
Asymmetric Michael addition of 1-acetylindolin-3-ones to β,γ-unsaturated α-ketoesters was investigated for the synthesis of chiral indolin-3-ones with two adjacent tertiary stereogenic centers. Under the catalysis of a chiral bifunctional squaramide derived from l-tert-leucine, a wide range of 1-acetylindolin-3-ones and β,γ-unsaturated α-ketoesters were well-tolerated in this transformation to ...
β-Isocupreidine (β-ICD) catalyzed asymmetric [4 + 2] cycloaddition of β,γ-unsaturated α-ketoesters with allenic esters afforded ester-substituted functionalized dihydropyran derivatives in high yields along with high enantioselectivities under mild conditions.
Azides and nitriles are important building blocks for the synthesis of nitrogen-containing bioactive compounds. The first example of enantioselective palladium-catalyzed decarboxylative allylation of α-azido and cyano β-ketoesters is reported. Indanone derivatives were obtained in 50-88% yield/77-97% ee and 46-98% yield/78-93% ee for azide and nitrile substituents, respectively. The required st...
A series of novel 1,4diazepines have been synthesized from β-diketones / β-ketoesters of 4acetylaminobenzene sulphonyl chloride. Desired compounds were prepared by the reaction of novel βdiketone / β-ketoester derivatives of [N4-(4acetylamino) benzene sulphonyl piperazinylN1-1bromopropane] with ethylenediamine to get 1, 4dizapines. All the newly synthesized compounds were characterized with IR ...
A highly stereoselective desymmetrization reaction of δ,δ-diaryl-α-diazo-β-ketoesters catalyzed by chiral dirhodium carboxylates forms aromatic cycloaddition products in up to 97% ee.
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