Metal‐Free Synthesis of Indolo3,2‐ c quinolines via S 8 ‐Mediated Hydrogen‐Borrowing Reduction/Cyclization/Aromatization Sequence

Key Points

• The aim is to develop a metal-free method for synthesizing indolo[3,2-c]quinolines using a single reaction step.
• Utilized S8 as a reducing agent in a one-pot reaction.
• Started with 2-(2-nitrophenyl)indoles and amines.
• Achieved reduction, bond cleavage, formation, and cyclization in one procedure.
• Synthesis yielded indolo[3,2-c]quinolines with 39%–75% efficiency.
• Demonstrated a practical approach under metal-free conditions.
• Successfully combined multiple reactions into a single process.