A Cascade Annulation for the Synthesis of 11H-Indolo[3,2-c]quinolines and In Vitro Anti-Inflammatory Assays

An efficient one-pot cascade annulation strategy to construct 11H-indolo[3,2-c]quinoline derivatives was reported under iodine/zinc acetate catalysis, using diarylalkynes and 2-bromoacetophenones, acetophenones, or methyl-containing carbon sources as starting materials (acting as both synthon and solvent). A series of target products were afforded in moderate to excellent yields. Preliminary biological evaluation revealed that several synthesized compounds exhibit significant anti-inflammatory activity in LPS-stimulated RAW264.7 cells. In particular, compound 3h displayed potent inhibition of NO production along with suppression of pro-inflammatory cytokines.