نتایج جستجو برای: spiro oxindolopyrrolizidines pyrrolidines

تعداد نتایج: 2463  

An efficient one-pot three-component procedure for the synthesis of new chiral spiro-oxindolopyrrolizidines with highly regio-, diastereo-, and enantioselective from 1,3-dipolar cycloaddition of azomethine ylides and optically pure active cinamoyl oxazolidinone are described. The process occurs at room temperature in aqueous ethanol as green solvent and in the absence of any bidentate chelating...

An efficient one-pot three-component procedure for the synthesis of new chiral spiro-oxindolopyrrolizidines with highly regio-, diastereo-, and enantioselective from 1,3-dipolar cycloaddition of azomethine ylides and optically pure active cinamoyl oxazolidinone are described. The process occurs at room temperature in aqueous ethanol as green solvent and in the absence of any bidentate chelating...

Khosrow Jadidi Mohammad Javad Taghizadeh,

An efficient one-pot three-component procedure for the synthesis of new chiral spiro oxindolopyrrolidines/pyrrolizidines with highly regio- and diastereo-enantio, selective from 1,3-dipolar cycloaddition of azomethine ylides and chiral menthol-drived trans-cinnamic are described. The mechanism of the reaction is discussed on basis of the assignment of the absolute configuration of one of the cy...

Journal: :iranian chemical communication 2014
mohammad javad taghizadeh khosrow jadidi

an efficient one-pot three-component procedure for the synthesis of new chiral spiro oxindolopyrrolidines/pyrrolizidines with highly regio- and diastereo-enantio, selective from 1,3-dipolar cycloaddition of azomethine ylides and chiral menthol-drived trans-cinnamic are described. the mechanism of the reaction is discussed on basis of the assignment of the absolute configuration of one of the cy...

Journal: :Chemical communications 2011
Qing-Hua Li Min-Chao Tong Jun Li Hai-Yan Tao Chun-Jiang Wang

Trifluoromethylated pyrrolidines have been synthesized via catalytic asymmetric 1,3-dipolar cycloaddition with excellent stereoselectivity for the first time. Epimerization of the endo-pyrrolidines obtained from cis-4,4,4-trifluorocrotonate into the exo-pyrrolidines was also revealed.

2014
Michael T. Corbett Qihai Xu Jeffrey S. Johnson

The stereoselective synthesis of trisubstituted 2-trifluoromethyl pyrrolidines by asymmetric Michael addition/hydrogenative cyclization is described. The direct organocatalytic addition of 1,1,1-trifluoromethylketones to nitroolefins proceeds under mild reaction conditions and low catalyst loadings to provide Michael adducts in high yield with excellent diastereo- and enantioselectivity. Cataly...

Journal: :Chemistry: A European Journal 2023

Pyrrolidines are intriguing scaffolds that can be found in a variety of natural products. They have numerous biological and organocatalytic uses. The asymmetric [3+2] cycloadditions employing metal catalysis with suitable chiral ligands is robust method for the synthesis enantioenriched pyrrolidines up to four centres. Recent advances summarized Review by Guiry Kumar (DOI. 10.1002/chem.20230029...

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