Acid‐Catalyzed Tandem Ritter and Mannich Reactions for Direct Access to 3‐Aryl 3‐amidooxindoles from Isatin

Abstract Three‐component tandem Ritter and Mannich reactions were developed for one‐pot arylation and acyl protected amination of isatin. The acid catalyzed reaction produced wide variety of 3‐aryl‐3‐amidooxindoles directly from commercially available isatin. The C3 functionalization of isatin is affected by condensation with electron rich arenes and nitriles or amides with concomitant C−C and C−N bonds formation. Substituted isatins, different nucleophiles (cyclic and acyclic N, N‐disubstituted arylamines), aliphatic nitriles, and amides expanded the scope of the reaction. The reaction is simple, general, efficient and can switch the amidation substrate from nitriles in Ritter reaction to amides in Mannich reaction.