One-pot synthesis of substituted indolo[1,2-a]quinolines under transition-metal-free conditions

Abstract A simple and efficient one-pot synthesis of substituted indolo[1,2- a ]quinolines under transition-metal-free conditions has been developed. When 2-fluorobenzaldehyde was treated with substituted 2-methylindoles in the presence of Cs 2 CO 3 , the desired products were typically obtained in good to excellent yields. This reaction sequence involves a nucleophilic aromatic substitution and a Knoevenagel condensation reaction. Our mechanistic investigation revealed that both reactions could proceed as an intermolecular reaction in the first step.