Results 1 to 10 of about 25,921 (206)

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

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   +8 more sources

Engaging Isatins and Amino Acids in Multicomponent One-Pot 1,3-Dipolar Cycloaddition Reactions—Easy Access to Structural Diversity [PDF]

Molecules, 2023
Multicomponent reactions (MCRs) have undoubtedly emerged as the most indispensable tool for organic chemists worldwide, finding extensive utility in the synthesis of intricate natural products, heterocyclic molecules with significant bioactivity, and ...
Hua Zhao, Yufen Zhao
doaj   +2 more sources

Diastereoselective Three-Component 1,3-Dipolar Cycloaddition to Access Functionalized β-Tetrahydrocarboline- and Tetrahydroisoquinoline-Fused Spirooxindoles [PDF]

Molecules
A chemselective catalyst-free three-component 1,3-dipolar cycloaddition has been described. The unique polycyclic THPI and THIQs were creatively employed as dipolarophiles, which led to the formation of functionalized β-tetrahydrocarboline- and ...
Yongchao Wang, Yu Chen, Shengli Duan, Yiyang Cao, Wenjin Sun, Mei Zhang, Delin Zhao, Donghua Hu, Jianwei Dong   +8 more
doaj   +2 more sources

Facile synthesis of hydantoin/1,2,4-oxadiazoline spiro-compounds via 1,3-dipolar cycloaddition of nitrile oxides to 5-iminohydantoins [PDF]

Beilstein Journal of Organic Chemistry
The cycloaddition of 1,3-dipoles at C=N bonds is a relatively rare process, in contrast to the widespread cycloaddition reactions at C=C, C≡C, and C=S bonds.
Juliana V. Petrova, Varvara T. Tkachenko, Victor A. Tafeenko, Anna S. Pestretsova, Vadim S. Pokrovsky, Maxim E. Kukushkin, Elena K. Beloglazkina   +6 more
doaj   +2 more sources

1,3-Dipolar cycloadditions of azomethine imines [PDF]

Organic & Biomolecular Chemistry, 2015
Azomethine imines react with alkenes and alkynes to give pyrazolines, pyrazolidines, pyrazolopyridines, indazoloisoquinolines, pyrazolo[1,5-a]isoquinolines and pyrazolopyrazolones through regio-, stereo- and enantioselective 1,3-dipolar cycloadditions.
Nájera, Carmen, Sansano, Jose M., Yus, Miguel   +2 more
openaire   +6 more sources

HUISGEN AND HIS ADVENTURES IN A PLAYGROUND OF MECHANISMS AND NOVEL REACTIONS [PDF]

Química Nova, 2021
The death of professor Rolf Huisgen (1920-2020) was announced on March 26th 2020, in the midst of the COVID-19 pandemic. Professor Huisgen was professor emeritus at the University of Munich in Germany, and studied in detail the mechanism of the 1,3 ...
Daniel T. G. Gonzaga, Luana da S. M. Forezi, Carolina G. de S. Lima, Patricia G. Ferreira, Fernando de C. da Silva, Vitor F. Ferreira   +5 more
doaj   +1 more source

MnVI-NP–Catalyzed Generation of Nitrile Oxides: Easy Access to Isoxazolines and Isoxazoles via Stereoselective 1,3-Dipolar Cyclo­addition Reactions

SynOpen, 2022
The versatility and effectiveness of MnVI-NPs as a catalyst is examined for the generation of nitrile oxides from aldoximes and subsequent 1,3-dipolar cycloaddition reactions.
Yasmin Saima, Saikat Khamarui
doaj   +1 more source

Ultrasound-assisted one-pot three-component synthesis of new isoxazolines bearing sulfonamides and their evaluation against hematological malignancies

Ultrasonics Sonochemistry, 2021
In the present study, following a one-pot two-step protocol, we have synthesized novel sulfonamides-isoxazolines hybrids (3a-r) via a highly regioselective 1,3-dipolar cycloaddition. The present methodology capitalized on trichloroisocyanuric acid (TCCA)
Aicha Talha, Cécile Favreau, Maxence Bourgoin, Guillaume Robert, Patrick Auberger, Lahcen EL Ammari, Mohamed Saadi, Rachid Benhida, Anthony R. Martin, Khalid Bougrin   +9 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

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

Molecules, 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