Peptidomimetic organocatalysts: efficient Michael addition of ketones onto nitroolefins with very low catalyst loading

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.

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 %).


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.


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.


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.


2015 ◽  
Vol 13 (20) ◽  
pp. 5636-5645 ◽  
Author(s):  
Jun-Hua Li ◽  
Da-Ming Du

An efficient chiral squaramide-catalysed enantioselective Michael addition of pyrazolin-5-ones to 3-nitro-2H-chromenes afforded chiral heterocycles containing both chroman and pyrazolone derivatives in high to excellent yields (up to 98%) with high enantioselectivities (up to 96%) under very low catalyst loading (0.2 mol%).


ChemInform ◽  
2015 ◽  
Vol 46 (7) ◽  
pp. no-no ◽  
Author(s):  
Srivari Chandrasekhar ◽  
Chintakunta Praveen Kumar ◽  
Togapur Pavan Kumar ◽  
Kothapalli Haribabu ◽  
Bharatam Jagadeesh ◽  
...  

Synthesis ◽  
2016 ◽  
Vol 48 (19) ◽  
pp. 3207-3216 ◽  
Author(s):  
Uğur Kaya ◽  
Pankaj Chauhan ◽  
Kristina Deckers ◽  
Rakesh Puttreddy ◽  
Kari Rissanen ◽  
...  

A low catalyst loading of a squaramide (0.5 mol%) and a silver(I) salt (1 mol%) efficiently catalyzes a one-pot asymmetric Michael addition/hydroalkoxylation reaction between 1,3-diketones and alkyne-tethered nitroalkenes. Depending on the 1,3-dicarbonyl substrate this cooperative catalytic approach opens access to tetrahydrobenzofurans or annulated dihydropyrans in moderate to excellent yields and very good to excellent enantioselectivities.


Author(s):  
BanniPreet Kaur ◽  
Vivek Sharma ◽  
Subash Chandra Sahoo ◽  
Swapandeep Singh Chimni

A low-catalyst loading Michael addition reaction of pyrazolyl nitroalkenes with 1,3-dicarbonyl derivatives has been carried out under mild reaction conditions to afford 4-substituted pyrazole derivatives in 60-87% yields and 82-96%...


Author(s):  
Long Chen ◽  
Shi-Lu Zheng ◽  
Yun-Xiang Zou ◽  
Zhong Wen ◽  
Jiafu Lin ◽  
...  

Facile synthesis of 2-phosphorylated 2H-chromenes has been accomplished herein via a Y(OTf)3-catalyzed dehydrative coupling of 2H-chromene hemiacetals with P(O)-H compounds. This protocol features low catalyst loading, mild reaction conditions, broad...


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