Synthesis of Polysubstituted Quinolines via Transition-Metal-Free Oxidative Cycloisomerization of <i>o</i>‑Cinnamylanilines

An efficient synthesis of 2-aryl 4-substituted quinolines from stable and readily available <i>o</i>-cinnamylanilines, prepared from anilines and cinnamylalcohols, has been developed. The reaction occurred via a regioselective 6-<i>endo-trig</i> intramolecular oxidative cyclization using KO^tBu as a mediator and DMSO as an oxidant at rt. The reaction showed a broad substrate scope with good to excellent yields.