Ricerc@Sapienza

Amide function is very important in both organic and medicinal chemistry. Benzamides can be obtained
in good to high yields by reaction of benzoin, primary or secondary amines, molecular oxygen and
electrogenerated superoxide anion (obtained with galvanostatic method). The advantage of using
electrogenerated superoxide anion is related to its counterion, the tetraethylammonium cation, which is
not tightly bound to the anion and thus renders superoxide highly reactive also in the absence of
additives (necessary when using KO2). The reaction conditions are very mild and only 0.5 F/mol are
necessary to obtain good yields in benzamides. This work points out that benzamides can be obtained
also starting from deoxybenzoin and benzil, via CC bond cleavage, with yields which depend on the
charge amount.
A mechanistic hypothesis (in part supported by the literature and by voltammetric studies) is reported,
which allows to explain the formation of byproducts and to define the role of oxygen and superoxide
anion.