Results 31 to 40 of about 16,669 (224)

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

Beilstein Journal of Organic Chemistry, 2015
The 1,3-dipolar cycloaddition of acyclic 2-diazo-1,3-dicarbonyl compounds (DDC) and thioketones preferably occurs with Z,E-conformers and leads to the formation of transient thiocarbonyl ylides in two stages.
Andrey S. Mereshchenko, Alexey V. Ivanov, Viktor I. Baranovskii, Grzegorz Mloston, Ludmila L. Rodina, Valerij A. Nikolaev   +5 more
doaj   +1 more source

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

Molecules, 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, Alexey K. Fedorenko, Alexey M. Starosotnikov, Alexander Kh. Shakhnes   +3 more
doaj   +1 more source

A Stepwise [4 + 3] Cycloaddition Reaction of the 1,3-Diphenyl-2-azaallyl Anion [PDF]

, 1993
The 1,3-diphenyl-2-azaallyl anion (1) undergoes [3 + 2] cycloaddition reactions with the s-cis-fixed 1,3-dienes 8-11. In contrast, 1,1,2,2,3,3-hexamethyl-4,5-bis(methylene)cyclopentane (7) reacts with 1 to give the [4 + 3] cycloadduct 13 and the linear 1,
Mayr, Herbert, Heigl, Ulrich W., Baran, Janusz   +2 more
core   +1 more source

Kinetic Resolution of Alkylidene Norcamphors via a Ligand-Controlled Umpolung-Type 1,3-Dipolar Cycloaddition

iScience, 2019
Summary: Development of a general catalytic and highly efficient method utilizing readily available precursors for the regio- and stereoselective construction of bioactive natural-product-inspired spiro architectures remains a formidable challenge in ...
Chong Shen, Yuhong Yang, Liang Wei, Wu-Wei Dong, Lung Wa Chung, Chun-Jiang Wang   +5 more
doaj   +1 more source

N-Alkylated dinitrones from isosorbide as cross-linkers for unsaturated bio-based polyesters

Beilstein Journal of Organic Chemistry, 2014
Isosorbide was esterified with acryloyl chloride and crotonic acid yielding isosorbide diacrylate (9a) and isosorbide dicrotonate (9b), which were reacted with benzaldehyde oxime in the presence of zinc(II) iodide and boron triflouride etherate as ...
Oliver Goerz, Helmut Ritter
doaj   +1 more source

A Suitable Functionalization of Nitroindazoles with Triazolyl and Pyrazolyl Moieties via Cycloaddition Reactions

Molecules, 2019
The alkylation of a series of nitroindazole derivatives with 1,2-dibromoethane afforded the corresponding N-(2-bromoethyl)- and N-vinyl-nitro-1H-indazoles.
Mohammed Eddahmi, Nuno M. M. Moura, Latifa Bouissane, Ouafa Amiri, M. Amparo F. Faustino, José A. S. Cavaleiro, Ricardo F. Mendes, Filipe A. A. Paz, Maria G. P. M. S. Neves, El Mostapha Rakib   +9 more
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

, 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 ...
Krim, Jamal, Taourirte, Mohamed, Engels, Joachim W., Moha Taourirte, Jamal Krim, Joachim W. Engels   +5 more
core   +1 more source

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

Beilstein 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, Olesya V. Khoroshilova, Anna G. Larina, Vitali M. Boitsov, Alexander V. Stepakov   +4 more
doaj   +1 more source

PHOSPHONATED ISOXAZOLIDINYL NUCLEOSIDES, A NEW CLASS OF MODIFIED NUCLEOSIDES [PDF]

Euromediterranean Biomedical Journal, 2014
This review offers an overview of the synthesis of phosphonated isoxazolidinyl nucleosides, a new class of interesting and potentially antiviral/antitumor agents.
Salvatore Giofrè
doaj   +1 more source

Synthesis of Heterocylic Compounds of Biological Interest from Carbohydrate Derivatives

Molecules, 2000
The synthesis of some isoxazolic compounds from carbohydrate derivatives is described. These products are obtained by 1,3-dipolar cycloaddition reaction and their functionalization leads to derivatives with potential biological activities.
M. F. Martinez Esperón, M. L. Fascio, N. B. D’Accorso   +2 more
doaj   +1 more source