Cascade Radical Cyclization of Propargylamines for Functionalized 3-Arylthioquinoline Formation.

A novel and efficient strategy for the direct synthesis of 3-arylthioquinoline derivatives via radical induced tandem cyclization of propargylamines with diaryl disulfides was developed. This protocol undergoes a cascade sulfuration/ cyclization/ oxidation/ aromatization pathway to afford the desired products in a broad substrate scope using readily available starting materials under mild conditions. Based on this strategy, we further modified 3-arylquinolines to obtain two novel deep blue fluorescent molecules, QLSCz and QLSTCz, with good optical properties through two-step synthesis by oxidation and electron donor modification.