1-4 bond orders—a static reactivity index for Diels-Alder reactions
Abstract
The bond order p14 between the 1 and 4 atoms of the diene provides a static reactivity index for Diels-Alder reactions. This bond order is closely correlated with Brown's para-localization energy, a dynamic index. Two theoretical explanations for the correlation of p14 with Diels-Alder reactivities are proposed.