Results 1 to 10 of about 17,890 (211)

Nitropyridines as 2π-Partners in 1,3-Dipolar Cycloadditions with N-Methyl Azomethine Ylide: An Easy Access to Condensed Pyrrolines

open access: yesMolecules, 2021
1,3-Dipolar cycloaddition reactions of 2-substituted 5-R-3-nitropyridines and isomeric 3-R-5-nitropyridines with N-methyl azomethine ylide were studied. The effect of the substituent at positions 2 and 5 of the pyridine ring on the possibility of the [3 ...
Maxim A. Bastrakov   +3 more
doaj   +1 more source

New Cycloadditon Reaction of 2-Chloroprop-2-enethioamides with Dialkyl Acetylenedicarboxylates: Synthesis of Dialkyl 2-[4,5-bis(alkoxycarbonyl)-2-(aryl{alkyl}imino)-3(2H)-thienylidene]-1,3-dithiole-4,5-dicarboxylates

open access: yesMolecules, 2022
The 1,3-dipolar cycloaddition of 1,2-dithiole-3-thiones with alkynes to form 1,3-dithioles is one of the most studied reactions in this class of polysulfur-containing heterocycles. Nucleophilic substitution of chlorine atoms in dimethyl 2-(1,2-dichloro-2-
Vladimir A. Ogurtsov, Oleg A. Rakitin
doaj   +1 more source

Fluorescent Azasteroids through Ultrasound Assisted Cycloaddition Reactions

open access: yesMolecules, 2021
We report here the synthesis and optical spectral properties of several new azasteroid derivatives. The formation of these compounds was explained based on the most probable mechanism.
Costel Moldoveanu   +2 more
doaj   +1 more source

On the strong difference in reactivity of acyclic and cyclic diazodiketones with thioketones: experimental results and quantum-chemical interpretation [PDF]

open access: yes, 2015
The 1,3-dipolar cycloaddition of acyclic 2-diazo-1,3-dicarbonyl compounds (DDC) and thioketones preferably occurs with Z,Econformers and leads to the formation of transient thiocarbonyl ylides in two stages.
Holleman   +8 more
core   +7 more sources

Synthesis of bis-spirocyclic derivatives of 3-azabicyclo[3.1.0]hexane via cyclopropene cycloadditions to the stable azomethine ylide derived from Ruhemann's purple

open access: yesBeilstein Journal of Organic Chemistry, 2022
A reliable method for the synthesis of bis-spirocyclic derivatives of 3-azabicyclo[3.1.0]hexanes through the 1,3-dipolar cycloaddition (1,3-DC) reactions of cyclopropenes to the stable azomethine ylide – protonated form of Ruhemann's purple (PRP) has ...
Alexander S. Filatov   +4 more
doaj   +1 more source

3-Benzoylisoxazolines by 1,3-Dipolar Cycloaddition: Chloramine-T-Catalyzed Condensation of α-Nitroketones with Dipolarophiles

open access: yesMolecules, 2021
In this study, 3-benzoylisoxazolines were synthesized by reacting alkenes with various α-nitroketones using chloramine-T as the base. The scope of α-nitroketones and alkenes is extensive, including different alkenes and alkynes to form various ...
Xinhui Pan   +8 more
doaj   +1 more source

Highly Efficient Construction of Sugar-Fused Spirochromanono Pyrrolidines/Pyrrolizidines/Thiolizidines via 1,3-Dipolar Cycloaddition of Azomethine Ylides

open access: yesSynOpen, 2017
A variety of sugar-fused chromanono pyrrolidines/pyrrolizidines/thiolizidines have been synthesized by intermolecular 1,3-dipolar cycloaddition reaction of azomethine ylides (generated from glucose aldehyde and different secondary amino acids) with ...
Sirisha Nallamala   +2 more
doaj   +1 more source

Synthesis of novel pyrazoles via [2+3]-dipolar cycloaddition using alkyne surrogates [PDF]

open access: yesTetrahedron Letters, 2010
The syntheses of an important class of hitherto unreported novel pyrazoles are described. The regioselective synthesis of 1,3,4,5-tetrasubstituted pyrazoles was achieved by the Huisgen cyclization of nitrile imines with a trisubstituted bromoalkene. The substituted bromoalkene functions as an alkyne synthon which was used to construct 5,5-disubstituted
Sureshbabu, Dadiboyena   +2 more
openaire   +2 more sources

Theoretical analysis of the mechanism and regioselectivity of the 1, 3-dipolar cycloaddition of E-3-(dimethylamino)-1-(10H-phenothiazin-2-yl)prop-2-en-1-one with some nitrilimines using DFT and the distortion/interaction model

open access: yesActa Chimica Slovenica, 2015
The regiochemistry of 1,3-dipolar cycloaddition reactions of E-3-(dimethylamino)-1-(10H-phenothiazin-2-yl) prop-2-en-1-one with some nitrilimines were investigated using density functional theory (DFT) -based reactivity indexes, activation energy ...
Farid Moeinpour, Amir Khojastehnezhad
doaj   +1 more source

Synthesis of 1,4-Disubstituted Mono and Bis-triazolocarbo-acyclonucleoside Analogues of 9-(4-Hydroxybutyl)guanine by Cu(I)-Catalyzed Click Azide-Alkyne Cycloaddition [PDF]

open access: yes, 2011
A series of novel mono-1,2,3-triazole and bis-1,2,3-triazole acyclonucleoside analogues of 9-(4-hydroxybutyl)guanine was prepared via copper(I)-catalyzed 1,3-dipolar cycloaddition of N-9 propargylpurine, N-1-propargylpyrimidines/as-triazine with the ...
Engels, Joachim W.   +2 more
core   +2 more sources

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