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 C6D6as 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. Watch it in H/D: A convenient method to perdeuterate aromatic compounds is reported using catalytic nonaflic acid and C6D6. Many of the deuterated aromatic building blocks can be functionalized under various conditions to afford products with an overall high degree of isotopic labeling.