Artículos de revistas
Revisiting the Stability of endo/exo Diels-Alder Adducts between Cyclopentadiene and 1,4-benzoquinone
Registro en:
Journal Of The Brazilian Chemical Society. Soc Brasileira Quimica, v. 21, n. 1, n. 112, n. 118, 2010.
0103-5053
WOS:000275106400016
10.1590/S0103-50532010000100017
Autor
Tormena, CF
Lacerda, V
de Oliveira, KT
Institución
Resumen
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) In this work it is presented a detailed theoretical analysis of the relative stability of endo/exo Diels-Alder adducts formed by the reaction between cyclopentadiene (1) and 1,4-benzoquinone (2). The intrinsic reaction coordinate (IRC) showed the existence of only one transition state for the reaction studied, for both endo 3 and exo 4 adducts. The energies of both adducts were obtained at high level of theory (CBS-Q) confirming that the endo adduct is more stable than exo, which is in the opposite way to the observed in reactions that usually follow Alder's rule. An electronic structure analysis was performed through NBO methodology, indicating that the attractive delocalization interaction predominates over the steric repulsive interaction in the endo adducts. In summary, for the studied cycloaddition reaction the endo adduct is the thermodynamic and kinetic product, which can be also confirmed by experimental data mentioned in this work. 21 1 112 118 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) FAPESP [05/59649-0, 06/03980-2, 07/03589-4, 2008/06619-4]