One‐Pot Synthesis of Nitrones from Primary Amines and Aldehydes Catalyzed by Methyltrioxorhenium

One‐pot condensation/oxidation of primary amines and aldehydes using urea–hydrogen peroxide (UHP) as the stoichiometric oxidant in the presence of methyltrioxorhenium (MTO) as catalyst affords nitrones in a simple and regioselective manner. UHP is a practical and safe source of H 2 O 2 , and its use here instead of aqueous H 2 O 2 solutions also simplifies greatly the workup procedure as extractions with organic solvents can be avoided. Typically, at the end of the reaction the solid urea is simply filtered off. From a sustainability point of view, this one‐pot synthesis is simple to perform, takes place under mild conditions, has a high atom economy, and releases water as the only by‐product.