Abstract

Bezocyclobutenes are useful compounds as precursors to o-quinodimethanes, which are highly reactive dienes. However, the thermal isomerization temperatures(IT) of substituted benzocyclobutenes to o-quinodimethanes have not been predictable based on the simple substituent effect. In this paper, we provide a simple method to predict the IT of benzocyclobutenes by calculation of the activation energies using a semi-empirical molecular orbital calculation. ITs of the various substituted benzocyclobutenes were estimated by this method.

Keywords: Bezocyclobutene, o-quinodimethane, thermal isomerization temperature, prediction, activation energy, semiempirical molecular orbital calculation, captodative effect, aminomethane, Diels-Alder reaction, cyanobenzocyclobutene