How do arenediazonium salts behave in deep eutectic solvents? A combined experimental and computational approach

Despite the growing use of Deep Eutectic Solvents (DESs) as green reaction media in a number of organic syntheses, no significant reactions of diazonium salts in these solvents are known in the literature. In this paper, we present the behavior of arenediazonium tetrafluoroborates in new halide salts/polyol-based DESs, the nature of which is investigated by means of a combined computational and experimental approach. A relatively fast (strictly depending on the electronic effects of the substituents bound to the aromatic ring) reduction reaction occurs initiated by the formation of a glycerolate-like species as proved by a thorough computational study aiming at elucidating the involved mechanism.