CuI in deep eutectic solvent is an efficient catalyst for the synthesis of indolo[۱,۲-a]quinoline derivatives

An efficient synthesis of substituted indolo[۱,۲-a]quinolines with indole in the reaction with ۲-iodobenzaldehyde derivatives in the present of CuI in deep eutectic solvent (N-phenyliminodiacetic acid: choline chloride (۲:۱ mol ratio)). The synthetic products were obtained in up to ۹۵% yield. Our mechanistic study confirmed that the reaction sequence involved an intermolecular Knoevenagel reaction followed by an intramolecular Ullmann-type coupling reaction.

Keywords:

Indolo[۱ , ۲-a]quinoline , Knoevenagel condensation , Ullmann-type reaction