Optically Pure Aminopolyols and Polyoxamic Acid Derivatives from Aziridine-2-carboxylates

1999 ◽  
Vol 52 (4) ◽  
pp. 259 ◽  
Author(s):  
Heribert Dollt ◽  
Volker Zabel

Various new chiral building blocks could easily be prepared from optically pure cis and trans ethyl 3-(1′,3′- dioxolan-4′-yl)aziridine-2-carboxylates. A stereochemically pure 1,3-dioxolan in the allyl position of an α-bromoacrylate induced a high (3R*,4′S*) selectivity in the Michael addition with an amine. After oxygen at the inducing centre was exchanged with nitrogen bearing a bulky substituent, the directing influence of this new group was examined. Solvent effects influencing the cis/trans ratio of aziridine formation are discussed.

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.


2020 ◽  
Author(s):  
sudershan gondi

<p><b>Abstract:</b> High to moderate diastereoselectivity and high chemical yield are observed in the Michael addition of ylide and chiral camphorpyrazolidinone ylide to an optically pure a,b-unsaturated carboxylic acid derivatives derived from a chiral camphorpyrazolidinone and a,b-unsaturated carbonyl respectively. A novel route to the asymmetric synthesis of cyclopropanation derivatives is described.</p>


1960 ◽  
Vol 38 (4) ◽  
pp. 557-566 ◽  
Author(s):  
R. A. Abramovitch ◽  
J. M. Muchowski

The Michael addition of diethyl malonate to 1-cyclohexene cyanide has been shown to give a mixture of the cis- and trans-diethyl 2-cyanocyclohexylmalonates in 72% and 28% yields respectively. The stereochemistry of the products was established by their unambiguous conversion to the respective cis- and trans-decahydroisoquinolines. Hydrogenation of a cyclohexane cyanide to the corresponding aminomethyl derivative takes place with retention of configuration. A number of substituted decahydroisoquinolines of known stereochemistry have been prepared. Decahydro-3,4-dioxoisoquinoline-4-phenylhydrazone underwent Fischer cyclization to a product assumed to be 2-oxo-octahydroindolo[2,3-d]isoquinoline indicating that the observation that 4-methyl-2,3-dioxopiperidine-3-phenylhydrazone did not undergo cyclization is not general for such 4-substituted piperidones.


2012 ◽  
Vol 8 ◽  
pp. 1485-1498 ◽  
Author(s):  
Tatyana E Shubina ◽  
Matthias Freund ◽  
Sebastian Schenker ◽  
Timothy Clark ◽  
Svetlana B Tsogoeva

A new guanidine-thiourea organocatalyst has been developed and applied as bifunctional organocatalyst in the Michael addition reaction of diethyl malonate to trans-β-nitrostyrene. Extensive DFT calculations, including solvent effects and dispersion corrections, as well as ab initio calculations provide a plausible description of the reaction mechanism.


2020 ◽  
Author(s):  
sudershan gondi

<p><b>Abstract:</b> High to moderate diastereoselectivity and high chemical yield are observed in the Michael addition of ylide and chiral camphorpyrazolidinone ylide to an optically pure a,b-unsaturated carboxylic acid derivatives derived from a chiral camphorpyrazolidinone and a,b-unsaturated carbonyl respectively. A novel route to the asymmetric synthesis of cyclopropanation derivatives is described.</p>


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

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.


1994 ◽  
Vol 42 (11) ◽  
pp. 2241-2250 ◽  
Author(s):  
Nobutaka FUJII ◽  
Kazuo NAKAI ◽  
Hiromu HABASHITA ◽  
Yuka HOTTA ◽  
Hirokazu TAMAMURA ◽  
...  

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.


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