Revisiting the Hammett p Parameter for the Determination of Philicity: Nucleophilic Substitution with Inverse Charge Interaction

摘要

Oxidation chemistry has always been one of the most important arenas for the interpretation and mastering of reactivity. Since the beginning of the last century, the interest of scientists in this area has been driven by the strong implications that this reactivity has in biological systems, and also because oxidations are an essential tool in functional-group transformations. Over the years, two alternative mechanistic pathways for oxygen transfer (OT) reactions, oxidations which proceed by an heterolytic cleavage of the oxygen-oxygen bond of the oxidant, have been proposed: electrophilic OT, in which the transferred oxygen attacks the substrate electrophilically and nucleophilic OT, which is usually described as a two-step process involving the addition of the peroxo compound to the substrate. This philicity scheme is nowadays well accepted and used to interpret oxidative reactivities in both artificial and biological sys-tems.