Electrochemical Indole Skeletal Editing via Single-Carbon Atom Insertion

Skeletal editing has emerged as a powerful and innovative tool in organic chemistry, offering an efficient approach to the synthesis of complex molecules. Conventional indole skeletal editing approaches predominantly rely on complex carbene precursors and/or transition-metal catalysis to achieve ring expansion. Herein, we report an electrochemical single-carbon insertion strategy for the skeletal editing of indoles into quinolines, which proceeds without the need for specialized reagents or transition-metal catalysts. The reaction is proposed to proceed via an electrooxidative denitrogenation process, in which in situ formed hydrazones generate reactive carbene intermediates that promote ring expansion. This strategy establishes a new activation platform for skeletal editing chemistry.