نتایج جستجو برای: 3 ketoesters

تعداد نتایج: 1811529  

Journal: :Organic & biomolecular chemistry 2008
Márcio W Paixão Martin Nielsen Christian Borch Jacobsen Karl Anker Jørgensen

The organocatalytic ring-opening of N-tosyl protected aziridines by beta-ketoesters under chiral PTC-conditions, leading to the formation of optically active aminoethyl functionalised compounds with up to 99% ee, has been developed.

Journal: :Symmetry 2021

The development of new and efficient methods, reagents, catalysts for the introduction fluorine atoms or fluorinated moieties in molecular scaffolds has become a topic paramount importance organic synthesis. In this framework, incorporation SCF3 group into molecule often led to beneficial effects on drug’s metabolic stability bioavailability. Here we report our studies aimed stereoselective syn...

2015
Abdul Sadiq Fawad Mahmood Farhat Ullah Muhammad Ayaz Sajjad Ahmad Faizan Ul Haq Ghazan Khan Muhammad Saeed Jan

BACKGROUND Based on the pharmacological potency and structural features of succinimides, this study was designed to synthesize new ketoesters derivatives of succinimides. Furthermore, the synthesized compounds were evaluated for their possible anticholinesterase and antioxidant potentials. The compounds were synthesized by organocatalytic Michael additions of α-ketoesters to N-aryl maleimides. ...

Journal: :Chemical communications 2009
Yingguang Zhu Changwei Zhai Yongli Yue Liping Yang Wenhao Hu

A facile synthesis of 2,3-dihydropyrrole derivatives has been achieved through the one-pot, three-component tandem reaction of diazo compounds with anilines and beta,gamma-unsaturated alpha-ketoesters in moderate to good yields.

Journal: :Chemical communications 2007
José Alemán Efraím Reyes Bo Richter Jacob Overgaard Karl Anker Jørgensen

The first organocatalytic "anti-Michael" reaction of cyclic-beta-ketoesters to unsaturated double bonds is described in a highly asymmetric version leading to the synthesis of alpha,alpha'-disubstituted branched double bonds as optically active Baylis-Hillman-like adducts.

Journal: :Organic & biomolecular chemistry 2011
Sandro Cacchi Giancarlo Fabrizi Antonella Goggiamani Antonia Iazzetti David Madec Giovanni Poli Guillaume Prestat

The palladium-catalyzed reaction of (hetero)aryl bromides, chlorides, and nonaflates with α-allyl-β-ketoesters provides ready efficient access to functionalized 2,3-dihydrofurans. The reaction tolerates several useful substituents including chloro, fluoro, ether, ketone, ester, cyano, and nitro groups.

Journal: :Organic & biomolecular chemistry 2012
Cheng-Kui Pei Yu Jiang Min Shi

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.

Journal: :Organic & biomolecular chemistry 2009
Kevin M Allan Boram D Hong Brian M Stoltz

A convenient method is disclosed for the synthesis of both 3-hydroxyisoquinolines and 2-hydroxy-1,4-naphthoquinones from beta-ketoesters using a one-pot aryne acyl-alkylation/condensation procedure. When performed in conjunction with a one-step method for the synthesis of the beta-ketoester substrates, this method provides a new route to these polyaromatic structures in only two steps from comm...

2012
Christopher A. Rose Sivaji Gundala Claire-Louise Fagan Johannes F. Franz Stephen J. Connon Kirsten Zeitler

It has been shown for the first time that relatively electron deficient triazolium pre-catalysts promote (at low loadings in the presence of base) highly chemoselective crossed acyloin condensation reactions between aldehydes and a-ketoesters to afford densely functionalized products incorporating a quaternary stereocentre of considerable synthetic potential. Hydroacylation pathways which have ...

2011
Lukas Hintermann Mauro Perseghini Antonio Togni

Titanium-based Lewis acids catalyze the α-fluorination of β-ketoesters by electrophilic N-F-fluorinating reagents. Asymmetric catalysis with TADDOLato-titanium(IV) dichloride (TADDOL = α,α,α',α'-tetraaryl-(1,3-dioxolane-4,5-diyl)-dimethanol) Lewis acids produces enantiomerically enriched α-fluorinated β-ketoesters in up to 91% enantiomeric excess, with either F-TEDA (1-chloromethyl-4-fluoro-1,4...

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