Digging on the Mechanism of Some Diels-Alder Reactions. The Role of the Reaction Electronic Flux

Abstract Within the framework of the reaction force analysis, the Marcus Potential Energy Function as well as the Activation Strain Model are characterized and used to rationalize the energetics of some representative Diels-Alder reactions involving three substituted furandione as dienophile, and a chiral anthracene, as diene. The analysis of reaction barriers indicates that the activation process of the reactions is dominated by the structural rearrangements of reactants which are mainly driven by the approach of diene to the dienophile. On the other hand, the electronic activity taking place along the reaction coordinate have been analyzed through the reaction electronic flux. It has been found that the electronic activity that emerge more intensively within the transition state region, is mainly due to electronic transfer effects, due to the breaking and forming π bonds. Although polarization is also present but to a lesser extent.