Results 31 to 40 of about 73,410 (278)

Incorporation of Spin Labels and Paramagnetic Tags for Magnetic Resonance Studies Using Cycloaddition Reactions as a Tool

Reactions
The cycloaddition reaction is one of the most common reactions in organic chemistry. It has been applied in various fields. Herein, we focus on the application of cycloaddition reactions in investigating biological molecules and materials using magnetic ...
Amarendra Nath Maity, Amiya Kumar Medda, Shyue-Chu Ke   +2 more
doaj   +1 more source

Diels–Alder reactions in confined spaces: the influence of catalyst structure and the nature of active sites for the retro-Diels–Alder reaction

Beilstein Journal of Organic Chemistry, 2016
Diels–Alder cycloaddition between cyclopentadiene and p-benzoquinone has been studied in the confined space of a pure silica zeolite Beta and the impact on reaction rate due to the concentration effect within the pore and diffusion limitations are ...
Ángel Cantín, M. Victoria Gomez, Antonio de la Hoz   +2 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 [PDF]

, 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., Krim, Jamal, Taourirte, Mohamed   +2 more
core   +2 more sources

Promotion mechanism of hydroxyl groups in catalyzing CO2 cycloaddition

Journal of CO2 Utilization
In this study, a series of hydroxy-functionalized quaternary ammonium salt catalysts, i.e., NEt3(HE)Br, NEt2(HE)2Br, NEt1(HE)3Br, and N(HE)4Br, were successfully prepared by quantitatively grafting hydrogen-bond donors (HBDs) as electrophilic sites on ...
Yiming Wang, Wensheng Wei, Yuxin Wang, Guangwen Xu, Jinggang Zhao, Lei Shi   +5 more
doaj   +1 more source

Unveiling the Chemistry of Higher-Order Cycloaddition Reactions within the Molecular Electron Density Theory

Chemistry, 2022
The higher-order cycloaddition (HOCA) reaction of tropone with cyclopentadiene (Cp) has been studied within the Molecular Electron Density Theory.
Luis R. Domingo, Mar Ríos-Gutiérrez, Patricia Pérez   +2 more
doaj   +1 more source

[2+2+2] Cycloaddition Reactions of Macrocyclic Systems Catalyzed by Transition Metals. A Review

Molecules, 2010
Polyalkyne and enediyne azamacrocycles are prepared from arenesulfonamides and various alkyne and alkene derivatives either under basic or neutral conditions.
Anna Roglans, Anna Pla-Quintana
doaj   +1 more source

Microwave-Assisted Regioselective Synthesis and 2D-NMR Studies of New 1,2,3-Triazole Compounds Derived from Acridone

Journal of Chemistry, 2021
A simple and mild protocol towards the synthesis of new 1,2,3-triazole compounds derived from acridone has been developed via regiospecific 1,3-dipolar cycloaddition reaction between 10-(prop-2-yn-1-yl)acridone derivatives and aromatic azides using CuI ...
Mohammed Aarjane, Siham Slassi, Bouchra Tazi, Amina Amine   +3 more
doaj   +1 more source

The Puzzle of the New Type of Intermediate in the Course of [2 + 2] Cycloaddition with the Participation of Conjugated Nitroalkenes: MEDT Computational Study

Molecules
The phenomena of regio- and stereoselectivity and the molecular mechanism of the [2 + 2] cycloaddition reaction between (E)-2-arylnitroethenes and the ynamine molecular system were analyzed using wb97xd/6-311 + G(d) (PCM) quantumchemical calculations. It
Radomir Jasiński, Agnieszka Kącka-Zych
doaj   +1 more source

[4 + 2]-Cycloadditions to 1 '-Phenyl-Substituted 3-Vinylindoles with N-Phenylmaleimide: An Access to New [a]Anellated Carbazole Derivatives

CHIMIA, 1987
The AlCl3-catalyzed [4 + 2]-cycloaddition of T-phenyl-substituted 3-vinylindoles with N-phenylmaleimide gives rise to new anellated carbazole derivatives with a high endo-preference.
Ludwig Pfeuffer, Ulf Pindur
doaj   +1 more source

X=Y–ZH compounds as potential 1,3-dipoles. Part 64: Synthesis of highly substituted conformationally restricted and spiro nitropyrrolidines via Ag(I) catalysed azomethine ylide cycloadditions [PDF]

, 2008
1,3-Dipolar reactions of imines of both acyclic and cyclic α-amino esters with a range of nitroolefins using a combination of AgOAc or Ag2O with NEt3 are described.
Albert, Amornraksa, Ayerbe, Becker, Berger, Bourguignon, Bryce, Cecilia Orgaz de la Cierva, Colin Kilner, Crooks, Dondas, Díaz-Ortiz, Fejes, Fejes, Gentles, Grigg, Grigg, Grigg, Grigg, Grigg, Grigg, Grigg, Grigg, Grigg, H. Ali Dondas, Hill, Kabalka, Krapcho, Lee, Mohammed A.B. Sarker, Nielson, Norman, Nyerges, Nyerges, Nyerges, Nyerges, Nyerges, Pak, Peterli, Pinna, Poornachandran, Poornachandran, Poornachandran, Ram, Rang, Ronald Grigg, Sader-Bakaouni, Shorter, Song, Thurkauf, Vivanco, Yan   +51 more
core   +1 more source