scholarly journals Asymmetric Sequential Michael Addition and Cyclization Reactions of 2-(2-Nitrovinyl)phenols Catalyzed by Bifunctional Amino-Squaramides

SynOpen ◽  
2021 ◽  
Vol 05 (04) ◽  
pp. 278-284
Author(s):  
Radovan Šebesta ◽  
Eva Veverková ◽  
Pavlína Molnosiová

AbstractIn this work, we describe the Michael addition–cyclization reaction of 2-(2-nitrovinyl)phenol with two different reactive Michael donors, which lead to chiral benzopyran derivatives. Specifically, bifunctional amino-squaramides with one or two chiral units in the side chains were evaluated as catalysts in these transformations. Furthermore, the utility of selected green solvents as reaction media for these processes was also tested. The best result was achieved with methyl-cyclopentanone-2-carboxylate as the Michael donor in ethyl (–)-l-lactate with quinine-based amino-squaramide as catalyst (yield 72%, dr >99:1, ee 99%).

2021 ◽  
Author(s):  
Jeena N. Baby ◽  
Lavanya Chandrasekar ◽  
Sea-Fue Wang ◽  
Sriram Balasubramanian ◽  
Ashwini Anantharaman ◽  
...  

By serving as alternatives to toxic and hazardous solvents, green solvents assist in implementing the idea of sustainability. The use of these neoeric reaction media dramatically reduces energy requirements and...


2005 ◽  
pp. 669-671 ◽  
Author(s):  
N. Srilakshmi Krishnaveni ◽  
K. Surendra ◽  
K. Rama Rao

2009 ◽  
Vol 351 (1-2) ◽  
pp. 141-146 ◽  
Author(s):  
Yun Shi ◽  
Jing Huang ◽  
Yan-Fang Yang ◽  
Lu-Yong Wu ◽  
Yan-Ning Niu ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Abdullah M. A. Al Majid ◽  
Mohammad Shahidul Islam ◽  
Assem Barakat ◽  
Mohamed H. M. Al-Agamy ◽  
Mu. Naushad

The importance of cooperative hydrogen-bonding effects has been demonstrated using novel 3-methylenecyclopropane-1,2-dicarboxylic acid (Feist’s acid (FA)) as hydrogen bond donor catalysts for the addition of indole and pyrrole totrans-β-nitrostyrene derivatives. Because of the hydrogen bond donor (HBD) ability, Feist’s acid (FA) has been introduced as a new class of hydrogen bond donor catalysts for the activation of nitroolefin towards nucleophilic substitution reaction. It has effectively catalyzed the Michael addition of indoles and pyrrole toβ-nitroolefins under optimum reaction condition to furnish the corresponding Michael adducts in good to excellent yields (up to 98%). The method is general, atom-economical, convenient, and eco-friendly and could provide excellent yields and regioselectivities. Some newly synthesized compounds were for examinedin vitroantimicrobial activity and their preliminary results are reported.


2017 ◽  
Vol 13 ◽  
pp. 612-619 ◽  
Author(s):  
Alejandro Castán ◽  
Ramón Badorrey ◽  
José A Gálvez ◽  
María D Díaz-de-Villegas

New pyrrolidine-based organocatalysts with a bulky substituent at C2 were synthesized from chiral imines derived from (R)-glyceraldehyde acetonide by diastereoselective allylation followed by a sequential hydrozirconation/iodination reaction. The new compounds were found to be effective organocatalysts for the Michael addition of aldehydes to nitroolefins and enantioselectivities up to 85% ee were achieved.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Marthe Carine Djuidje Fotsing ◽  
Dieudonné Njamen ◽  
Zacharias Tanee Fomum ◽  
Derek Tantoh Ndinteh

Abstract Cyclic and polycyclic compounds containing moieties such as imidazole, pyrazole, isoxazole, thiazoline, oxazine, indole, benzothiazole and benzoxazole benzimidazole are prized molecules because of the various pharmaceutical properties that they display. This led Prof. Landor and co-workers to engage in the synthesis of several of them such as alkylimidazolenes, oxazolines, thiazolines, pyrimidopyrimidines, pyridylpyrazoles, benzoxazines, quinolines, pyrimidobenzimidazoles and pyrimidobenzothiazolones. This review covers the synthesis of biologically active heterocyclic compounds by the Michael addition and the double Michael addition of various amines and diamines on allenic nitriles, acetylenic nitriles, hydroxyacetylenic nitriles, acetylenic acids and acetylenic aldehydes. The heterocycles were obtained in one step reaction and in most cases, did not give side products. A brief discussion on the biological activities of some heterocycles is also provided.


2018 ◽  
Vol 34 (5) ◽  
pp. 727-740 ◽  
Author(s):  
Lavinia Macarie ◽  
Nicoleta Plesu ◽  
Smaranda Iliescu ◽  
Gheorghe Ilia

Abstract Organophosphorus chemistry was developed in the last decade by promoting the synthesis reactions using ionic liquids either as solvent or catalyst. Ionic liquids (ILs), the so-called “green solvents”, have gained interest in the synthesis of organophosphorus compounds as alternatives to flammable and toxic organic solvents and catalysts. ILs have beneficial properties because they provide high solubility for many organic and inorganic compounds or metal complexes, have no vapor pressure, and are reusable. Also, in some cases, they can enhance the reactivity of chemical reagents. In this review, we aimed at showing the synthesis of different organophosphorus compounds under green and mild conditions using ILs as reaction media or catalysts, according to a trend developed in the last years. A novel trend is to perform these syntheses under microwave irradiation conditions together with ILs as solvents and catalysts.


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