Chemical and Electrochemical Oxidative Activation of Arenol Derivatives for Carbon-Carbon Bond Formation

Abstract

The oxidative activation of arenes is a powerful and versatile synthetic tactic that enables various functionalization of aromatic rings. Central to this chemistry are oxygenated arenes such as hydroxylated arenes or arenols and their simple alkyl ethers whose electron-releasing functions facilitate the oxidation process. These two classes of arenol derivatives can lead to three different types of oxidized intermediates, each of which expresses its own chemical reactivity that can be exploited for specific bond formation. Free arenols can be subjected to either one- or two-electron oxidation processes to furnish either neutral arenoxy ArO. radicals or arenoxenium ArO+ ions depending on the mode of oxidative activation used. Arenol ethers initially furnish radical cationic ArOR+. species, whose chemistry often expresses the duality of their electronic nature. This review highlights the chemical, biochemical and electrochemical oxidative activation modes that can be used to convert arenol derivatives into either ArO., ArO+ or ArOR+. species and focuses on the structural elaboration of these intermediates in selective carbon-carbon bond-forming reactions.