Efficient Brønsted-Acid-Catalyzed Deuteration of Arenes and Their Transformation to Functionalized Deuterated Products

A convenient method to perdeuterate aromatic compounds is reported. Commercially available nonaflic acid (C4F9SO3H) in combination with C6D6 as the deuterium source provided access to a series of highly labeled arenes. Some of them were then used as building blocks for the preparation of functionalized deuterated products. A wide range of synthetic procedures were investigated. They involved traditional methods such as halogenation or nucleophilic substitution, but also metal-catalyzed cross coupling and C−X bond activation. The transformations comprised redox-neutral, oxidative as well as reductive reactions, and mechanistically, ionic, radical and pericyclic processes were covered. Under many conditions, the overall degree of deuteration remained high; in C−X activation reactions, a more pronounced re-protonation was observed.