ChemInform Abstract: ONE-STEP FORMATION OF (9)PARACYCLOPHA-3,5-DIENES BY A CYCLOADDITION REACTION

1979 ◽  
Vol 10 (7) ◽  
Author(s):  
F. KATAOKA ◽  
S. NISHIDA
Keyword(s):  
Cycloaddition Reaction ◽  
One Step

scholarly journals A molecular electron density theory study of the [3 + 2] cycloaddition reaction of nitrones with ketenes

2017 ◽  
Vol 15 (7) ◽  
pp. 1618-1627 ◽  
Author(s):  
Mar Ríos-Gutiérrez ◽  
Andrea Darù ◽  
Tomás Tejero ◽  
Luis R. Domingo ◽  
Pedro Merino
Keyword(s):  
Electron Density ◽  
Cycloaddition Reaction ◽  
Molecular Electron ◽  
One Step ◽  
Molecular Electron Density Theory ◽  
Electrophilic Character

The zw-type 32CA reactions of nitrones with ketenes are controlled by the nucleophilic character of the nitrone and the electrophilic character of the ketene. They are chemo- and regio-selective and the use of electrophilic ketenes changes the mechanism from one-step to two-step.

One-step Functionalization of Mildly and Strongly Reduced Graphene Oxide with Maleimide: An Experimental and Theoretical Investigation of the Diels-Alder [4+2] Cycloaddition Reaction

2021 ◽  
Author(s):  
Alfonso Ferretti ◽  
Sourab Sinha ◽  
Luca Sagresti ◽  
Esteban Araya-Hermosilla ◽  
Mirko Prato ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Large Scale ◽  
Cycloaddition Reaction ◽  
Diels Alder ◽  
Reduced Form ◽  
Graphene Nanocomposites ◽  
Exfoliated Graphene ◽  
Reduced Graphene ◽  
One Step

For large-scale graphene applications, such as the production of polymer-graphene nanocomposites, exfoliated graphene oxide (GO) and its reduced form (rGO) are presently considered very suitable starting material, showing enhanced chemical...

scholarly journals ONE-STEP FORMATION OF [9]PARACYCLOPHA-3,5-DIENES BY A CYCLOADDITION REACTION

1978 ◽  
Vol 7 (9) ◽  
pp. 1053-1056 ◽  
Author(s):  
Fumio Kataoka ◽  
Shinya Nishida
Keyword(s):  
Cycloaddition Reaction ◽  
One Step

One-Step Synthesis of Oxodimethylenemethane−Transition Metal Complexes and Palladium-Catalyzed Cycloaddition Reaction

1996 ◽  
Vol 61 (15) ◽  
pp. 4971-4974 ◽  
Author(s):  
Isao Ikeda ◽  
Akihiro Ohsuka ◽  
Kazuyoshi Tani ◽  
Toshikazu Hirao ◽  
Hideo Kurosawa
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Cycloaddition Reaction ◽  
Palladium Catalyzed ◽  
One Step

scholarly journals On the Question of Zwitterionic Intermediates in the [3 + 2] Cycloaddition Reactions between C-arylnitrones and Perfluoro 2-Methylpent-2-ene

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7147
Author(s):  
Katarzyna Mitka ◽  
Katarzyna Fela ◽  
Aleksandra Olszewska ◽  
Radomir Jasiński
Keyword(s):  
Dft Calculations ◽  
Molecular Mechanism ◽  
Intermolecular Interactions ◽  
Cycloaddition Reaction ◽  
Reaction Centers ◽  
Cycloaddition Reactions ◽  
Reaction Paths ◽  
One Step ◽  
Step Mechanism

The molecular mechanism of the [3 + 2] cycloaddition reaction between C-arylnitrones and perfluoro 2-methylpent-2-ene was explored on the basis of DFT calculations. It was found that despite the polar nature of the intermolecular interactions, as well as the presence of fluorine atoms near the reaction centers, all reactions considered cycloaddition proceed via a one-step mechanism. All attempts for the localization of zwitterionic intermediates on the reaction paths were not successful. Similar results were obtained regardless of the level of theory applied.

scholarly journals An electron localization function analysis of the molecular mechanism and the C–O bond formation in the [3+2] cycloaddition reaction involving zwitterionic type between a nitrone and an electron deficient ethyne

2019 ◽  
Vol 45 ◽  
pp. 146867831982574
Author(s):  
Abdelilah Benallou ◽  
Habib El Alaoui El Abdallaoui ◽  
Hocine Garmes
Keyword(s):  
Electron Density ◽  
Function Analysis ◽  
Bond Formation ◽  
Cycloaddition Reaction ◽  
Intrinsic Reaction Coordinate ◽  
Dimethyl Acetylenedicarboxylate ◽  
Central Carbon ◽  
One Step ◽  
Free Activation Energy ◽  
Step Mechanism

The mechanistic nature of a [3+2] cycloaddition reaction involving zwitterionic species has been investigated, and the changes of electron density related to the O–C and C–C bond formation along the intrinsic reaction coordinate have been characterized. This polar [3+2] cycloaddition reaction, which takes place through a non-concerted two-stage one-step mechanism, proceeds with a moderate Gibbs free activation energy of 21 kcal mol−1. The reaction begins by the creation of a pseudoradical centre at the central carbon, first on the dimethyl acetylenedicarboxylate, and second on the nitrone framework. This immediately favours the formation of the first O–C single bond by donation of some electron density of the oxygen atom lone pairs, which represents the most attractive centre in this cycloaddition reaction.

scholarly journals The Participation of 3,3,3-Trichloro-1-Nitroprop-1-Ene in the [3 + 2] Cycloaddition Reaction with Selected Nitrile N-oxides in the Light of the Experimental and MEDT Quantum Chemical Study

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6774
Author(s):  
Karolina Zawadzińska ◽  
Mar Ríos-Gutiérrez ◽  
Karolina Kula ◽  
Przemysław Woliński ◽  
Barbara Mirosław ◽  
...  
Keyword(s):  
Electron Density ◽  
Quantum Chemical Study ◽  
Cycloaddition Reaction ◽  
Chemical Study ◽  
Free Energies ◽  
Molecular Electron ◽  
One Step ◽  
Molecular Electron Density Theory ◽  
Favorable Reaction ◽  
Type 3

The regioselective zw-type [3 + 2] cycloaddition (32CA) reactions of a series of aryl-substituted nitrile N-oxides (NOs) with trichloronitropropene (TNP) have been both experimentally and theoretically studied within the Molecular Electron Density Theory (MEDT). Zwitterionic NOs behave as moderate nucleophiles while TNP acts as a very strong electrophile in these polar 32CA reactions of forward electron density flux, which present moderate activation Gibbs free energies of 22.8–25.6 kcal·mol−1 and an exergonic character of 28.4 kcal·mol−1 that makes them irreversible and kinetically controlled. The most favorable reaction is that involving the most nucleophilic MeO-substituted NO. Despite Parr functions correctly predicting the experimental regioselectivity with the most favorable O-CCCl3 interaction, these reactions follow a two-stage one-step mechanism in which formation of the O-C(CCl3) bond takes place once the C-C(NO2) bond is already formed. The present MEDT concludes that the reactivity differences in the series of NOs come from their different nucleophilic activation and polar character of the reactions, rather than any mechanistic feature.

scholarly journals Quantum Chemical Investigation of the Formation of Spiroheterocyclic Compounds Via the (3 + 2) Cycloaddition Reaction of 1-methyl-3-(2,2,2-trifluoroethylidene)pyrrolidin-2-one with Diazomethane and Nitrone Derivatives

2021 ◽  
Author(s):  
George Baffour Pipim ◽  
Richard Tia ◽  
Evans Adei
Keyword(s):  
Electron Density ◽  
Cycloaddition Reaction ◽  
Mechanism Analysis ◽  
Olefinic Bond ◽  
Activation Barriers ◽  
Atomic Spin ◽  
One Step ◽  
Complex Architecture ◽  
Electron Donating Groups ◽  
Polar Reaction

Spirocycles are important structures in drug development due to their inherent biological activity. Their complex architecture usually presents many synthetic difficulties which are efficiently resolved with detailed theoretical studies. The chemo-, regio- and stereoselectivities of the formation of spiroheterocyclic compounds via the (3 + 2) cycloaddition (32CA) reaction of 1-methyl-3-(2,2,2-trifluoroethylidene)pyrrolidin-2-one (A1) derivatives with diazomethane and nitrone derivative have been studied at the M06-2X/6-311G(d,p) level of theory. The reactions of diazomethane (A2) and N-methyl-C-phenyl nitrone (A3) derivatives with 1-methyl-3-(2,2,2-trifluoroethylidene)pyrrolidin-2-one derivatives (A1) occurs chemoselectively along the olefinic bond of A1 via an asynchronous one-step mechanism. Analysis of the electrophilic (  and nucleophilic (  Parr functions at the different reaction sites in A1 shows that A2 and A3 add across the atomic centers with the largest Mulliken and NBO atomic spin densities. Both electron-donating groups (EDGs) and electron-withdrawing groups (EWGs) on the A3 molecule do not affect the observed preferred pathway in its 32CA reaction with A1 whereas the electronic and steric nature of the substituent on the A2 molecule influences the preferred pathway in the 32CA reaction of A1 and A2. The title reaction proceeds via forward electron denisity flux (FEDF), where electron density fluxes from the three-atom components (A2 and A3) to A1. The computed global electron density transfer (GEDT) values suggest that the 32CA of A1 with diazomethane is a polar reaction while the 32CA reaction of A1 with N-methyl-C-phenyl nitrone is a non-polar reaction, and an inverse relationship has been established between the polar character of the reactions and activation barriers. In all the reactions studied, the selectivities are kinetically controlled.

Sign in / Sign up

Export Citation Format

Share Document