scholarly journals Green synthesis of CuO nanoparticles using Lantana camara flower extract and their potential catalytic activity towards the aza-Michael reaction

RSC Advances ◽  
2020 ◽  
Vol 10 (24) ◽  
pp. 14374-14385 ◽  
Author(s):  
Rakesh Chowdhury ◽  
Aslam Khan ◽  
Md. Harunar Rashid
Keyword(s):  
Catalytic Activity ◽  
Green Synthesis ◽  
Michael Addition ◽  
Michael Reaction ◽  
Addition Reaction ◽  
Cuo Nanoparticles ◽  
Synthesis Process ◽  
Michael Addition Reaction ◽  
Flower Extract ◽  
Convenient Synthesis

An easy and convenient synthesis process is reported for the synthesis of CuO nanoparticles using plant extract for use as a catalyst in the aza-Michael addition reaction.

Direct organocatalytic asymmetric Michael reaction of fluorine hemiaminal-type nucleophile to 4-nitro-5-styrylisoxazoles

2020 ◽  
Vol 7 (11) ◽  
pp. 1343-1348
Author(s):  
Luyao Li ◽  
Bo Zhu ◽  
Huihui Fan ◽  
Zhiyong Jiang ◽  
Junbiao Chang
Keyword(s):  
Michael Addition ◽  
Michael Reaction ◽  
Addition Reaction ◽  
Michael Addition Reaction ◽  
Asymmetric Michael Addition ◽  
Asymmetric Michael Reaction ◽  
First Time

Herein, we report a chiral bifunctional thiourea catalyzed asymmetric Michael addition reaction between 2-(trifluoromethyl)oxazol-5(2H)-one as a direct C-2-position nucleophile to 4-nitro-5-styrylisoxazoles for the first time.

Highly efficient synthesis of novel methyl 132-methylene mesopyropheophorbide a and its stereoselective Michael addition reaction

2015 ◽  
Vol 13 (7) ◽  
pp. 1992-1995 ◽  
Author(s):  
Jiazhu Li ◽  
Yang Liu ◽  
Xi-Sen Xu ◽  
Yan-Long Li ◽  
Shan-Guo Zhang ◽  
...  
Keyword(s):  
Michael Addition ◽  
Michael Reaction ◽  
Addition Reaction ◽  
Efficient Synthesis ◽  
Michael Addition Reaction ◽  
Highly Efficient ◽  
Ph Dependent

pH-Dependent regioselective condensation of methyl mesopyropheophorbide a with HCHO is studied and stereoselective Michael reaction of the 132-methylene product is also discussed.

scholarly journals Synthesis and evaluation of new guanidine-thiourea organocatalyst for the nitro-Michael reaction: Theoretical studies on mechanism and enantioselectivity

2012 ◽  
Vol 8 ◽  
pp. 1485-1498 ◽  
Author(s):  
Tatyana E Shubina ◽  
Matthias Freund ◽  
Sebastian Schenker ◽  
Timothy Clark ◽  
Svetlana B Tsogoeva
Keyword(s):  
Reaction Mechanism ◽  
Dft Calculations ◽  
Solvent Effects ◽  
Michael Addition ◽  
Michael Reaction ◽  
Addition Reaction ◽  
Diethyl Malonate ◽  
Theoretical Studies ◽  
Michael Addition Reaction ◽  
The Michael Addition

A new guanidine-thiourea organocatalyst has been developed and applied as bifunctional organocatalyst in the Michael addition reaction of diethyl malonate to trans-β-nitrostyrene. Extensive DFT calculations, including solvent effects and dispersion corrections, as well as ab initio calculations provide a plausible description of the reaction mechanism.

scholarly journals Comparison of Cinchona Catalysts Containing Ethyl or Vinyl or Ethynyl Group at Their Quinuclidine Ring

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3034 ◽  
Author(s):  
Nagy ◽  
Fehér ◽  
Dargó ◽  
Barabás ◽  
Garádi ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Michael Addition ◽  
Quantum Chemical ◽  
Addition Reaction ◽  
Michael Addition Reaction ◽  
Acid Base ◽  
Ethyl Vinyl ◽  
Ethynyl Group ◽  
Asymmetric Michael Addition ◽  
Vinyl Group

Numerous cinchona organocatalysts with different substituents at their quinuclidine unit have been described and tested, but the effect of those saturation has not been examined before. This work presents the synthesis of four widely used cinchona-based organocatalyst classes (hydroxy, amino, squaramide, and thiourea) with different saturation on the quinuclidine unit (ethyl, vinyl, ethynyl) started from quinine, the most easily available cinchona derivative. Big differences were found in basicity of the quinuclidine unit by measuring the pKa values of twelve catalysts in six solvents. The effect of differences was examined by testing the catalysts in Michael addition reaction of pentane-2,4-dione to trans-β-nitrostyrene. The 1.6–1.7 pKa deviation in basicity of the quinuclidine unit did not result in significant differences in yields and enantiomeric excesses. Quantum chemical calculations confirmed that the ethyl, ethynyl, and vinyl substituents affect the acid-base properties of the cinchona-thiourea catalysts only slightly, and the most active neutral thione forms are the most stable tautomers in all cases. Due to the fact that cinchonas with differently saturated quinuclidine substituents have similar catalytic activity in asymmetric Michael addition application of quinine-based catalysts is recommended. Its vinyl group allows further modifications, for instance, recycling the catalyst by immobilization.

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