Thermal Aromatizations of 2-Vinylmethylenecyclopropane and 3-Vinylcyclobutene

Date

2012-07-06

Author

Bozkaya, Ugur
Özkan, İlker

Metadata

Show full item record

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

Item Usage Stats

181
views

0
downloads

A comprehensive theoretical investigation of thermal rearrangements of 2-vinylmethylenecyclopropane and 3-vinylcyclobutene is carried out employing density functional theory and high level ab initio methods, such as the complete active space self-consistent field, multi-reference second-order Moller-Plesset perturbation theory, and coupled-cluster singles and doubles with perturbative triples. In all computations, Pople's polarized triple-zeta split valence basis set, 6-311G(d,p), is utilized. The potential energy surface for the relevant system is explored to provide theoretical insights for the thermal aromatizations of 2-vinylmethylenecyclopropane and 3-vinylcyclobutene. The rate constant for each isomerization reaction is computed using the transition state theory. The simultaneous first-order ordinary-differential equations are solved numerically for the considered system to obtain time-dependent concentrations, hence the product distributions at a given temperature. Our results demonstrate that at high temperatures thermal aromatizations of 2-vinylmethylenecyclopropane (at 700 degrees C and higher) and 3-vinylcyclobutene (at 500 degrees C and higher) are feasible under appropriate experimental conditions. However, at low temperatures (at 500 degrees C and lower), 2-vinylmethylenecyclopropane yields 3-methylenecyclopentene as a unique product, kinetically, and the formation of benzene is not favorable. Similarly, at 300 degrees C and lower temperatures, 3-vinylcyclobutene can only yield trans-1,3,5-hexatriene (major) and cis-1,3,5-hexatriene (minor). At 300 < T < 500 degrees C, 3-vinylcyclobutene almost completely yields 1,3-cyclohexadiene. Hence, our computations provide a useful insight for the synthesis of substituted aromatic compounds. Further, calculated energy values (reaction energies and activation parameters) are in satisfactory agreement with the available experimental results.

Subject Keywords

Conrotatory Electrocyclic Reactions, Coupled-Cluster Singles, Unimolecular Isomerization, Energy Surface, Vinylcyclopropane, Rearrangements, Allylidenecyclopropane, CCSD, Ring, Vinylmethylenecyclopropane

URI

https://hdl.handle.net/11511/32530

Journal

JOURNAL OF ORGANIC CHEMISTRY

DOI

https://doi.org/10.1021/jo300877w

Collections

Graduate School of Natural and Applied Sciences, Article

Suggestions

OpenMETU
Core

Thermal denitrogenation of 7-isopropylidene-2,3-diaza-norbornene: formation of substituted 3-methylene-(1,4)-pentadienes Bozkaya, Ugur; Özkan, İlker (2012-01-01) A theoretical study of the thermal denitrogenation of 7-isopropylidene-2,3-diaza-norbornene is carried out by employing density functional theory and high level ab initio methods, such as the complete active space self-consistent field, multi-reference second-order Moller-Plesset perturbation theory, and coupled-cluster singles and doubles with perturbative triples. In all computations Pople's polarized triple-zeta split valence basis set, 6-311G(d,p), is utilized. The potential energy surface for the relev...
Thermal Rearrangements of 1-Ethynyl-2-methylcyclopropane: A Computational Study Bozkaya, Ugur; Özkan, İlker (2012-03-29) In this research, a comprehensive theoretical investigation of the thermal rearrangements of 1-ethynyl-2-methylcyclopropane is carried out employing density functional theory (DFT), with the B3LYP functional, and high-level ab initio methods, such as the complete active space self-consistent field (CASSCF), multireference second-order Moller-Plesset perturbation theory (MRMP2), and coupled-cluster singles and doubles with perturbative triples [CCSD(T)]. In all computations Pople's polarized triple-zeta spli...
Theoretical Study of Thermal Rearrangements of 1-Hexen-5-yne, 1,2,5-Hexatriene, and 2-Methylenebicyclo[2.1.0]pentane Bozkaya, Ugur; Özkan, İlker (2012-03-02) In this research, a comprehensive theoretical investigation of the thermal rearrangements of 1-hexen-5-yne, 1,2,5-hexatriene, and 2-methylenebicyclo[2.1.0]pentane is carried out employing density functional theory (DFT) and high level ab initio methods, such as the complete active space self-consistent field (CASSCF), multireference second-order Moller-Plesset perturbation theory (MRMP2), and coupled-cluster singles and doubles with perturbative triples [CCSD(T)]. The potential energy surface (PES) for the ...
Potential Energy Surfaces for Rearrangements of Berson Trimethylenemethanes Bozkaya, Ugur; Özkan, İlker (2012-03-08) In this research, thermal rearrangements of the Berson trimethylenemethanes (Berson-TMMs) have been investigated by employing density functional theory (DFT) and high-level ab initio methods, such as the complete active space self-consistent field (CASSCF), multireference second-order Moller-Plesset perturbation theory (MRMP2), multireference configuration interaction singles and doubles (MRCISD), and coupled-cluster singles and doubles with perturbative triples [CCSD(T)]. In all computations Pople's polari...
HF and DFT studies and vibrational spectra of 1,2-bis(2-pyridyl) ethylene and its zinc (II) halide complexes Ozhamam, Z.; Yurdakul, Murat Hayrettin; Yurdakul, S. (2007-03-11) Ab initio restricted Hartree-Fock and density function theory calculations using BLYP, B3LYP and B3PW91 functionals were carried out to study molecular structure and vibrational spectrum of 1,2-bis(2-pyridyl)ethylene (which is abbreviated as bpe). Comparison of calculated and experimental results indicates the density functional B3LYP and BLYP/6-311G* methods are more accurate in predicting fundamental vibrational frequencies than the scaled other approaches. On the basis of calculated results, assignment o...

Citation Formats

U. Bozkaya and İ. Özkan, “Thermal Aromatizations of 2-Vinylmethylenecyclopropane and 3-Vinylcyclobutene,” JOURNAL OF ORGANIC CHEMISTRY, pp. 5714–5723, 2012, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/32530.