نتایج جستجو برای: 3 ketoesters

تعداد نتایج: 1811529  

2015
Raghunath Chowdhury Johannes Schörgenhumer Johanna Novacek Mario Waser

This communication describes the first proof of concept for an asymmetric α-cyanation of β-ketoesters using a hypervalent iodine-based electrophilic cyanide-transfer reagent. A series of different organocatalysts has been investigated and it was found that the use of naturally occurring Cinchona alkaloids allows obtaining the target products in good yields and with moderate enantioselectivities...

Journal: :Angewandte Chemie 2014
Fu-Lin Zhu Yuan Zou De-Yang Zhang Ya-Hui Wang Xin-Hu Hu Song Chen Jie Xu Xiang-Ping Hu

The first enantioselective copper-catalyzed decarboxylative propargylic alkylation has been developed. Treatment of propargyl β-ketoesters with a catalyst, prepared in situ from [Cu(CH3 CN)4 BF4 ] and a newly developed chiral tridentate ketimine P,N,N-ligand under mild reaction conditions, generates β-ethynyl ketones in good yields and with high enantioselectivities without requiring the pregen...

In this work, SO3H-functionalizedphthalimide (SFP) as a SO3H-containing solid acid is prepared by the reaction of phthalimide with chlorosulfonic acid, and characterized by FT-IR, 1H and 13C NMR, Mass, TG, DTG, XRD and SEM. Then, it is utilized as a highly efficient, heterogeneous and green catalyst for the one-pot multi-component condensation of dime...

Journal: :iranian chemical communication 2015
abdolkarim zare maryam dashtizadeh maria merajoddin

a highly efficient, simple and clean solvent-free protocol for the synthesis of polyhydroquinolines is described. the one-pot multi-component condensation reaction between arylaldehydes, dimedone (5,5-dimethylcyclohexane-1,3-dione), β-ketoesters and ammonium acetate in the presence of catalytic amount of (2.5 mol%) melamine trisulfonic acid (mtsa) as a recyclable, green and attractive sulfonic ...

Journal: :Angewandte Chemie 2021

N-Substituted α-amino esters are widely used as chiral intermediates in a range of pharmaceuticals. Here we report the enantioselective biocatalyic synthesis N-substituted through direct reductive coupling α-ketoesters and amines employing sequence diverse metagenomic imine reductases (IREDs). Both enantiomers were obtained with high conversion excellent enantioselectivity under mild reaction c...

2012
S. Kalaivani N. Padma Priya S. Arunachalam

A family of Schiff bases was synthesized by the reactions of o-aminobenzoic acid and Knovenegal condensate of β-ketoesters in 1:1 ratio. The newly synthesized Schiff bases were characterized by Elemental analyses and spectral (FT-IR, UV–Vis and H-NMR) studies and the structures have been proposed tentatively. These compounds were subjected to study their biocidal efficacy against S. epidermidis...

Journal: :Organic & biomolecular chemistry 2011
Jianze Ma You Huang Ruyu Chen

A novel NHC-catalyzed three-component domino strategy to access high functionalized cis-ε-ketoesters with excellent yields (up to 98%) and high stereoselectivities (up to 20:1) is documented. The title domino reactions are atom economical and work on a broad range of substrates. The relative stereochemistry could be explained by a cascade crossed-benzoin/oxy-Cope rearrangement/esterification pr...

Journal: :The Journal of organic chemistry 2015
Zhongwen Li Jianyu Dong Xiuling Chen Qiang Li Yongbo Zhou Shuang-Feng Yin

A general and efficient phosphorous acid-catalyzed cyclocondensation of β-ketoesters with o-aminobenzamides via selective C-C bond cleavage leading to quinazolinones is developed. This reaction proceeds smoothly under metal- and oxidant-free conditions, giving both 2-alkyl- and 2-aryl-substituted quinazolinones in excellent yields. This strategy can also be applied to the synthesis of other N-h...

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