scholarly journals Asymmetric Michael addition reactions catalyzed by calix[4]thiourea cyclohexanediamine derivatives

2018 ◽  
Vol 14 ◽  
pp. 1901-1907 ◽  
Author(s):  
Zheng-Yi Li ◽  
Hong-Xiao Tong ◽  
Yuan Chen ◽  
Hong-Kui Su ◽  
Tangxin Xiao ◽  
...  
Keyword(s):  
Michael Addition ◽  
Addition Reactions ◽  
Reaction Conditions ◽  
Catalytic Center ◽  
Asymmetric Michael Addition ◽  
Thiourea Group ◽  
High Yields ◽  
Upper Rim ◽  
Optimal Reaction

A number of upper rim-functionalized calix[4]thiourea cyclohexanediamine derivatives have been designed, synthesized and used as catalysts for enantioselective Michael addition reactions between nitroolefins and acetylacetone. The optimal catalyst 2 with a mono-thiourea group exhibited good performance in the presence of water/toluene (v/v = 1:2). Under the optimal reaction conditions, high yields of up to 99% and moderate to good enantioselectivities up to 94% ee were achieved. Detailed experiments clearly showed that the upper rim-functionalized hydrophobic calixarene scaffold played an important role in cooperation with the catalytic center to the good reactivities and enantioselectivities.

Highly Enantioselective Michael Addition of Cyclic Diketones to β,γ-Unsaturated α-Keto Esters Catalyzed by Squaramide Organocatalyst

Synthesis ◽  
2022 ◽  
Author(s):  
Zhi-Wei Ma ◽  
Chuan-Chuan Wang ◽  
Quan-Jian Lv ◽  
Xiao-Pei Chen ◽  
Ai-Qin Li ◽  
...  
Keyword(s):  
Michael Addition ◽  
Large Scale ◽  
Catalyst System ◽  
Catalyst Loading ◽  
Reaction Conditions ◽  
Keto Esters ◽  
Bicyclic Compounds ◽  
Asymmetric Michael Addition ◽  
High Yields ◽  
Low Catalyst Loading

AbstractA new tertiary amine-squaramide organocatalyst has been developed and applied to the asymmetric Michael addition of cyclic diketones to β,γ-unsaturated α-keto esters. The catalyst system performed well with a low catalyst loading of 1 mol% under mild reaction conditions. A series of synthetically and pharmaceutically useful chiral bicyclic compounds were obtained in high yields (up to 97%) with excellent enantioselectivities (up to 99 % ee). Furthermore, this catalytic system can be used efficiently in large-scale reactions with the yields and enantioselectivities being maintained.

Asymmetric Michael addition reactions catalyzed by a novel upper-rim functionalized calix[4]squaramide organocatalyst

2020 ◽  
Vol 31 (12) ◽  
pp. 3259-3262
Author(s):  
Ke Yang ◽  
Zhiyan Ma ◽  
Hong-Xiao Tong ◽  
Xiao-Qiang Sun ◽  
Xiao-Yu Hu ◽  
...  
Keyword(s):  
Michael Addition ◽  
Addition Reactions ◽  
Asymmetric Michael Addition ◽  
Upper Rim

Synthesis of 4-arylethyl-6-arylpyrimidine-2-thiols through aza-Michael addition/nucleophilic addition/aromatization tandem reactions

2018 ◽  
Vol 24 (1) ◽  
pp. 23-26
Author(s):  
Zheng Li ◽  
Wenli Song ◽  
Jiaojiao He ◽  
Yan Du ◽  
Jingya Yang
Keyword(s):  
Efficient Method ◽  
Michael Addition ◽  
Nucleophilic Addition ◽  
Tandem Reactions ◽  
Reaction Conditions ◽  
High Yields ◽  
Work Up

Abstract An efficient method for the synthesis of the title compounds by reactions of divinyl ketones with thiourea is described. This protocol has the advantages of high yields, mild reaction conditions and simple work-up procedure.

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.

Catalytic asymmetric addition reactions leading to carbon-carbon bond formation: Phenyl and alkenyl transfer to aldehydes and alkynylation of α-imino esters

2006 ◽  
Vol 78 (2) ◽  
pp. 267-274 ◽  
Author(s):  
Jian-Xin Ji ◽  
Jing Wu ◽  
Lijin Xu ◽  
Chiu-Wing Yip ◽  
Kim Hung Lam ◽  
...  
Keyword(s):  
Bond Formation ◽  
Optically Active ◽  
Amino Acid Derivatives ◽  
Addition Reactions ◽  
Terminal Alkynes ◽  
Reaction Conditions ◽  
Carbon Carbon Bond ◽  
Catalytic Asymmetric ◽  
High Yields ◽  
Imino Esters

Optically active tertiary aminonaphthol ligands were obtained by a new, convenient procedure and were found to catalyze the enantioselective alkenyl and phenyl transfer to aldehydes in high yields and excellent enantiomeric excesses (ee's). The catalytic asymmetric introduction of alkynyl functionality to α-amino acid derivatives was realized by the direct addition of terminal alkynes to α-imino ester in the presence of chiral copper(I) complex under mild reaction conditions.

scholarly journals Asymmetric Michael Addition Organocatalyzed by α,β-Dipeptides under Solvent-Free Reaction Conditions

Molecules ◽  
2017 ◽  
Vol 22 (8) ◽  
pp. 1328 ◽  
Author(s):  
C. Gabriela Avila-Ortiz ◽  
Lenin Díaz-Corona ◽  
Erika Jiménez-González ◽  
Eusebio Juaristi
Keyword(s):  
Michael Addition ◽  
Solvent Free ◽  
Reaction Conditions ◽  
Asymmetric Michael Addition ◽  
Solvent Free Reaction
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