Potassium Hydroxide Catalysed Intermolecular Aza-Michael Addition of 3-Cyanoindole to Aromatic Enones

Synlett ◽  
2017 ◽  
Vol 28 (10) ◽  
pp. 1227-1231 ◽  
Author(s):  
Jingya Yang ◽  
Tianyuan Li ◽  
Hongyan Zhou ◽  
Nana Li ◽  
Dongtai Xie ◽  
...  

Indole is one of the utmost important heterocycles as it is an essential nucleus of many pharmaceutical compounds. Its aza-Michael reaction, however, is underdeveloped because of the moiety’s inherent characteristics. Here, a potassium hydroxide catalysed intermolecular aza-Michael reaction of 3-cyanoindole with aromatic enones is described. A variety of chalcone derivatives are well tolerated and afford the corresponding N-adducts in moderate to high yields. The use of a cheap catalyst, low catalyst loading, mild reaction temperature, and good substrate tolerance make this procedure a direct and facile method for the preparation of N1-functionalized indoles.

2012 ◽  
Vol 8 ◽  
pp. 699-704 ◽  
Author(s):  
Saet Byeol Woo ◽  
Dae Young Kim

The highly enantioselective Michael addition of 2-hydroxy-1,4-naphthoquinones to nitroalkenes, promoted by binaphthyl-modified chiral bifunctional organocatalysts is described. This reaction afforded the chiral functionalized naphthoquinones in high yields (81–95%) and excellent enantioselectivities (91–98% ee) under low catalyst loading (1 mol %).


RSC Advances ◽  
2014 ◽  
Vol 4 (57) ◽  
pp. 30325-30331 ◽  
Author(s):  
Srivari Chandrasekhar ◽  
Chintakunta Praveen Kumar ◽  
Togapur Pavan Kumar ◽  
Kothapalli Haribabu ◽  
Bharatam Jagadeesh ◽  
...  

The syntheses and applications of peptidomimetic triazole-based catalysts are described as efficient organocatalysts in Michael reaction with low loading.


Synthesis ◽  
2022 ◽  
Author(s):  
Zhi-Wei Ma ◽  
Chuan-Chuan Wang ◽  
Quan-Jian Lv ◽  
Xiao-Pei Chen ◽  
Ai-Qin Li ◽  
...  

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.


Synthesis ◽  
2019 ◽  
Vol 51 (16) ◽  
pp. 3142-3150
Author(s):  
Hongyan Zhou ◽  
Xiancheng Xiang ◽  
Ben Ma ◽  
Ganggang Wang ◽  
Zhixia Zhang ◽  
...  

A lithium chloride catalyzed aza-Michael reaction of pyrazoles to α,β-unsaturated imides has been developed. A range of aromatic and aliphatic α,β-unsaturated imides are found to be suitable for the established method, providing the corresponding aza-Michael adducts in up to 93% yields. The inexpensive catalyst, good substrate tolerance, and ease of scale-up make this procedure highly practical.


2021 ◽  
Vol 25 ◽  
Author(s):  
Neda Reihani ◽  
Hamzeh Kiyani

: An efficient synthesis of 4-arylidene-3-alkylisoxazole-5(4H)-ones has been implemented via the three-component cyclocondensation of aryl(heteroaryl)aldehydes with hydroxylamine hydrochloride and β-ketoesters. The potassium 2,5-dioxoimidazolidin-1-ide has been introduced as the new organocatalyst to facilitate of this heterocyclization. In the current process, three starting materials, including substituted benzaldehydes/heterocyclic aromatic aldehydes, hydroxylamine hydrochloride, and ethyl acetoacetate/propyl acetoacetate/butyryl acetoacetate have been successfully used for the synthesize of the number of substituted isoxazole-5(4H)-ones in good to high yields in ethylene glycol as a green reaction medium at 80 ºC. The low catalyst loading is also a main advantage over the some reported catalysts.


Synthesis ◽  
2020 ◽  
Author(s):  
Ying Zhou ◽  
Xiong-Wei Liu ◽  
Shun-Qin Chang ◽  
Qi-Lin Wang ◽  
Shuang Chen ◽  
...  

A general and practical three-component regioselective 1,3-dipolar cycloaddition of 3-amino-oxindole-based azomethine ylides and coumarins has been developed. This reaction displayed good substrate tolerance and gave a diverse array of biologically relevant spiro[ox-­i­ndole-pyrrolidine-dihydrocoumarin] derivatives bearing four contiguous stereocenters including one spiro quaternary center in moderate to high yields (up to 90%) with high diastereoselectivities (up to 15:1 dr). It is based on the application of carboxylic acid activated coumarins as dienophiles followed by a decarboxylation process. The possible mechanism of the 1,3-dipolar cycloaddition is proposed via an exo′-transition state. Furthermore, this is the first example of decarboxylative-mediated regioselective 1,3-dipolar cycloaddition of 3-amino-oxindole-based azomethine ylides and coumarins.


2021 ◽  
Vol 17 ◽  
pp. 494-503
Author(s):  
Deniz Tözendemir ◽  
Cihangir Tanyeli

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.


Catalysts ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 14
Author(s):  
Ning Lin ◽  
Qiu-Xiang Wei ◽  
Li-Hua Jiang ◽  
Yan-Qiu Deng ◽  
Zhen-Wei Zhang ◽  
...  

A rosin-derived bifunctional squaramide catalyzed asymmetric Michael addition of malononitrile with chalcones was discovered. This protocol provides a methodology for the facile synthesis of chiral γ-cyano carbonyl compounds in high yields and enantioselectivities (up to 99% yield and 90% ee) with a lower catalyst loading (0.3 mol%). The predominant R-configured adducts were obtained by this organocatalystic reaction, according to the experimental findings.


2012 ◽  
Vol 67 (10) ◽  
pp. 1021-1029 ◽  
Author(s):  
Magnus Rueping ◽  
Stefan A. Moreth ◽  
Michael Bolte

The enantioselective synthesis of 2-aryl-substituted 2,3-dihydroquinolin-4-ones, a class of heterocyclic compounds with interesting biological activities, has been achieved through a Brønsted acidcatalyzed enantioselective intramolecular Michael addition. The products are available in moderate to high yields and with good enantioselectivities.


2020 ◽  
Vol 24 (13) ◽  
pp. 1397-1458
Author(s):  
Shagufta Kamal ◽  
Ameer Fawad Zahoor ◽  
Sajjad Ahmad ◽  
Rabia Akhtar ◽  
Iqra Khaliq ◽  
...  

: Michael reaction is the nucleophilic addition of active methylene compounds to conjugated olefins, resultantly affording a variety of biologically active scaffolds with high enantiopurity. To improve the reaction yield, as well as enantioselectivity of the product, a variety of catalysts (amine-based catalysts, bifunctional L-proline amides, bifunctional squaramides, chiral ionic liquids, cinchona alkaloids, enzymes, indolinols, metal catalysts, peptide derived catalytic system, phase transfer catalysts, pyrrolidine based organocatalysts) have been investigated by a different era of chemists. Besides this, different methodologies have been developed to improve reaction yield and enantioselectivity of the targeted products with low catalyst loading. : This review article provides a concise overview of the catalysts applied recently by different scientists in the Michael addition reaction. Moreover, current strategies and potential applications of this reaction have also been illustrated in this review.


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