Copper-catalyzed synthesis and anticancer activity evaluation of indolo[1,2-a]quinoline derivatives

Abstract

A simple and effective one-pot synthesis of substituted indolo[1,2-a]quinolines has been developed. The desired products were obtained in up to 98% yield when substituted 2-methyindoles were treated with 2-iodobenzaldehyde in the presence of Cs2CO3, CuI and L-proline. Our mechanistic study confirmed that the reaction sequence involved an intermolecular Knoevenagel reaction followed by an intramolecular Ullmann-type coupling reaction. Moreover, some of the synthesized compounds were found to be active against human breast (MCF-7) and colorectal (HCT-116) cancer cells with IC50 values of 27.96 μM and in the range of 6.21–46.91 μM, respectively.