Bronsted Acid-Catalyzed Decarboxylative Redox Amination: Formation of N-Alkylindoles from Azomethine Ylides by Isomerization

A Bronsted acid-catalyzed decarboxylative redox amination involving aldehydes with 2-carboxyindoline for the synthesis of N-alkylindoles is described. The decarboxylative condensations of aldehydes with 2-carboxyindoline produce azomethine ylides in situ, which then transform into N-alkylindoles by isomerization.