N-Heterocyclic Carbene-Catalysed Mukaiyama–Michael Reaction and Mukaiyama Aldol/Mukaiyama–Michael Three-Component Coupling Reaction

2017 ◽  
Vol 70 (4) ◽  
pp. 436 ◽  
Author(s):  
Kim Nguyen ◽  
David W. Lupton
Keyword(s):  
Michael Addition ◽  
Michael Reaction ◽  
Coupling Reaction ◽  
Enol Ethers ◽  
Chalcone Derivatives ◽  
Mukaiyama Aldol ◽  
Related Reaction ◽  
Three Component Coupling

An N-heterocyclic carbene-catalysed Mukaiyama–Michael addition between several trimethylsilyl (TMS) enol ethers and chalcone derivatives has been discovered. In addition, a related reaction cascade involving dehydrative Mukaiyama aldol followed by a Mukaiyama–Michael addition process has been developed. The later reaction can also be achieved as a three-component coupling reaction. The enantioselective variant of these reactions has been examined with homochiral catalysts. Though these catalysts were active, they fail to achieve enantioinduction.

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.

Enantioselective Michael Addition of Malonates to Enones

2020 ◽  
Vol 24 (7) ◽  
pp. 746-773
Author(s):  
Péter Bakó ◽  
Tamás Nemcsok ◽  
Zsolt Rapi ◽  
György Keglevich
Keyword(s):  
Michael Addition ◽  
Activity Relationship ◽  
Chalcone Derivatives ◽  
Michael Additions ◽  
Michael Reactions ◽  
Structure Activity ◽  
Cyclic Enones ◽  
Michael Acceptors ◽  
Relationship Of ◽  
Enantioselective Catalysts

: Many catalysts were tested in asymmetric Michael additions in order to synthesize enantioenriched products. One of the most common reaction types among the Michael reactions is the conjugated addition of malonates to enones making it possible to investigate the structure–activity relationship of the catalysts. The most commonly used Michael acceptors are chalcone, substituted chalcones, chalcone derivatives, cyclic enones, while typical donors may be dimethyl, diethyl, dipropyl, diisopropyl, dibutyl, di-tert-butyl and dibenzyl malonates. This review summarizes the most important enantioselective catalysts applied in these types of reactions.

scholarly journals N-Alkylation/aldol reaction of α-aldimino thioesters: a facile three-component coupling reaction

RSC Advances ◽  
2021 ◽  
Vol 11 (22) ◽  
pp. 13097-13104
Author(s):  
Makoto Shimizu ◽  
Asako Higashino ◽  
Isao Mizota ◽  
Yusong Zhu
Keyword(s):  
Aldol Reaction ◽  
Coupling Reaction ◽  
Three Component Coupling

Treatment of α-aldimino thioesters with dialkylzinc reagents in the presence of aldehydes or imines gives three-component coupling products in good yields with good to high anti-selectivities.

scholarly journals PEG-embedded KBr3: A recyclable catalyst for multicomponent coupling reaction for the efficient synthesis of functionalized piperidines

2011 ◽  
Vol 7 ◽  
pp. 1334-1341 ◽  
Author(s):  
Sanny Verma ◽  
Suman L Jain ◽  
Bir Sain
Keyword(s):  
Coupling Reaction ◽  
Recyclable Catalyst ◽  
Efficient Synthesis ◽  
Molecular Bromine ◽  
Keto Ester ◽  
One Step ◽  
High Yields ◽  
Multicomponent Coupling ◽  
Three Component Coupling

PEG-embedded potassium tribromide ([K+PEG]Br3 −) was found to be an efficient and recyclable catalyst for the synthesis of functionalized piperidines in high yields in a one step, three component coupling between aldehyde, amine and β-keto ester. At the end of the reaction the [K+PEG]Br3 − was readily regenerated from the reaction mixture by treating the residue containing [K+PEG]Br− with molecular bromine.

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