A theoretical study of the cycloaddition between cyclopentadiene and allylideneammonium cation: An AM1 study

Date

2002-12-09

Author

Zora, Metin

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

179
views

0
downloads

The Diels-Alder reaction between cyclopentadiene and allylideneammonium cation has been studied by means of AMI semiempirical method. Allylideneammonium cation can add to cyclopentadiene via its either C=C or C=N bond. For each cycloaddition, four reactive channels have been characterized corresponding to the endo-s-trans, endo-s-cis, exo-s-trans and exo-s-cis approach modes. The results indicate that C=C bond of allylideneammonium cation is more reactive as dienophile than its C=N bond in reaction with cyclopentadiene and the reaction takes place along a stepwise mechanism. The first and rate-limiting step is the nucleophilic attack of cyclopentadiene to the beta-carbon atom of the imminium ion to give an intermediate cation, and the second step is associated to the ring closure of this intermediate cation to afford the final cycloadduct. The transition structures, energetic aspects and other factors controlling the reaction outcome are discussed as well.

Subject Keywords

Cycloaddition, AM1 calculations, Cyclopentadiene, Iminium ion, Allylideneammonium cation, Diels-Alder reaction

URI

https://hdl.handle.net/11511/36077

Journal

Journal of Molecular Structure: THEOCHEM

DOI

https://doi.org/10.1016/s0166-1280(02)00566-3

Collections

Department of Chemistry, Article

Suggestions

OpenMETU
Core

An investigation of the formation mechanism of allene or alkyne in the 6,7-benzobicyclo[3,2.1]octane system by deuterium labeling experiments Taskesenligil, Y; Tumer, F; Kazaz, C; Balcı, Metin (1999-01-01) In order to reveal the real intermediate in the base-promoted reaction of 1, 3-bromo-4,4-dideuterio-6,7-benaobicyclo[3.2.1]octa-2,6-diene 10 was synthesized and its HBr elimination reaction studied. Reaction of 10 with potassium tert-butoxide yielded butoxyl ether 18 in which proton-deuterium exchange has occured.
A theoretical study on the strong codimer of C-60 and Si-60, C58Si58 Türker, Burhan Lemi (2001-07-09) The strong codimer Of C-60 and Si-60 that is C58Si58 is considered for AM1 type semiempirical molecular orbital treatment at the, restricted Hartree-Fock level. The results reveal that C58Si58 structure should be highly endothermic but a stable molecule. The structure is expected to have some nonlinear properties.
A COMPARATIVE-STUDY OF THE PERFORMANCE OF SOLID SUPPORTED AND SOLUBLE UREASE FOR THE ENZYMATIC-HYDROLYSIS OF UREA DEMIREL, G; AKOVALI, G; TANYOLAC, A; Hasırcı, Nesrin (1992-01-01) The performance of both free and solid supported urease for the enzymatic hydrolysis of urea was studied. Kinetic analysis of reaction rate data shows that the kinetic data were consistent with the proposed model. Statistical tests validated the model. Despite the deactivation of ureases, the immobilized enzyme could be the choice for a technological process aiming at the detoxification of blood in haemoperfusion columns.
The synthesis of zinc, chloride and fluoride doped nano hydroxylapatites by precipitation method and investigation of their mechanical, structural and biological properties Uysal, İdil; Evis, Zafer; Severcan, Feride; Department of Biomedical Engineering (2011) This study aimed synthesizing hydroxylapatite (HA) and Zn2+, F- and Cl- doped HA by solution precipitation method. The synthesized compounds were sintered at 1100°C for 1h. For structural characterization, density of the samples were measured by Archimedes’ method. It was observed that Zn2+ addition increased the density significantly whereas F- caused a decrease and Cl- increased the density with a little amount. XRD was applied to the samples and it was found that co-doping of Zn2+ and F- ions decreased t...
A novel one-pot synthesis of ferrocenyl-substituted 1,2,4-oxadiazoles Zora, Metin; Kelgokmen, YILMAZ (Elsevier BV, 2014-06-01) One-pot synthesis of 5-ferrocenyl-1,2,4-oxadiazoles via the reaction between 3-ferrocenylpropynal and amidoximes is described. 3-Ferrocenylpropynal reacts with a variety of amidoximes in the presence of KOH in refluxing dioxane to afford a broad range of 5-ferrocenyl-1,2,4-oxadiazole derivatives. The reaction first produces the corresponding conjugate addition product which, upon cyclization and rearrangement, yields the targeted 1,2,4-oxadiazole. The reaction appears to be general for a diversity of amidox...

Citation Formats

M. Zora, “A theoretical study of the cycloaddition between cyclopentadiene and allylideneammonium cation: An AM1 study,” Journal of Molecular Structure: THEOCHEM, pp. 121–133, 2002, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/36077.