Visible Light Induced Cyclization of O-Alkenylcarboxanilide to 2-Quinolinone

A free radical cyclization reaction induced by visible light using cheap and readily available O-alkenylfor. manilide was developed. The strategy was used to synthesize fifteen 2-quinolinone derivatives in good to excellent yields. This method is simple and efficient,with mild conditions and excellent functional group compatibility. Mean. while,a plausible mechanism is proposed on the basis of several mechanistic experiments and literature precedents. This method not only provides a new type of organic reaction involving O-alkenylformylanilide,but also provides a new pathway for the photocatalytic synthesis of quinolinones.