Bifunctional Cinchona Alkaloid/Thiourea Catalyzes Direct and Enantioselective Vinylogous Michael Addition of 3-Alkylidene Oxindoles to Nitroolefins

2012 ◽  
Vol 51 (25) ◽  
pp. 6200-6204 ◽  
Author(s):  
Claudio Curti ◽  
Gloria Rassu ◽  
Vincenzo Zambrano ◽  
Luigi Pinna ◽  
Giorgio Pelosi ◽  
...  
Keyword(s):  
Michael Addition ◽  
Cinchona Alkaloid

Cinchona alkaloid-based chiral catalysts act as highly efficient multifunctional organocatalysts for the asymmetric conjugate addition of malonates to nitroolefins

2015 ◽  
Vol 13 (40) ◽  
pp. 10216-10225 ◽  
Author(s):  
Veeramanoharan Ashokkumar ◽  
Ayyanar Siva
Keyword(s):  
Michael Addition ◽  
Quaternary Ammonium ◽  
Conjugate Addition ◽  
Quaternary Ammonium Salts ◽  
Cinchona Alkaloid ◽  
Ammonium Salts ◽  
Addition Reactions ◽  
Chiral Catalysts ◽  
Reaction Conditions ◽  
Highly Efficient

New pentaerythritol tetrabromide based chiral quaternary ammonium salts have been prepared and used as organocatalysts for enantioselective Michael addition reactions between various nitroolefins and Michael donors under mild reaction conditions with very good chemical yields and ee's.

Organocatalyzed enantioselective Michael addition/cyclization cascade reaction of 3-isothiocyanato oxindoles with arylidene malonates

2016 ◽  
Vol 14 (47) ◽  
pp. 11250-11260 ◽  
Author(s):  
Raghunath Chowdhury ◽  
Mukesh Kumar ◽  
Sunil K. Ghosh
Keyword(s):  
Michael Addition ◽  
Cascade Reaction ◽  
Cinchona Alkaloid ◽  
Bifunctional Catalysts

Both enantiomers of functionalized 3,2′-pyrrolidinyl spirooxindoles were obtainedviaa Michael-cyclization cascade reaction using pseudoenantiomeric cinchona alkaloid derived thiourea based bifunctional catalysts.

scholarly journals The synthesis of chiral β-naphthyl-β-sulfanyl ketones via enantioselective sulfa-Michael reaction in the presence of a bifunctional cinchona/sulfonamide organocatalyst

2021 ◽  
Vol 17 ◽  
pp. 494-503
Author(s):  
Deniz Tözendemir ◽  
Cihangir Tanyeli
Keyword(s):  
Michael Addition ◽  
Michael Reaction ◽  
Cinchona Alkaloid ◽  
Catalyst Loading ◽  
Asymmetric Transformations ◽  
Chalcone Derivatives ◽  
Mild Conditions ◽  
Michael Adducts

Cinchona alkaloid-derived organocatalysts are widely employed in various asymmetric transformations, yielding products with high enantiopurity. In this respect, a bifunctional quinine-derived sulfonamide organocatalyst was developed to catalyze the asymmetric sulfa-Michael reaction of naphthalene-1-thiol with trans-chalcone derivatives. The target sulfa-Michael adducts were obtained with up to 96% ee under mild conditions and with a low (1 mol %) catalyst loading. Selected enantiomerically enriched sulfa-Michael addition products were subjected to oxidation to obtain the corresponding sulfones.

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