Metal‐Free Oxidative Annulation/Cyclization of 1,6‐Enynes for the Synthesis of 4‐Carbonylquinolines
作者:Xiao‐Feng Xia、Wei He、Dawei Wang
DOI:10.1002/adsc.201900013
日期:2019.6.18
Herein we report on the development of a metal‐freeoxidativeannulation reaction of 1,6‐enynes, leading to 4‐carbonylquinolines by using dioxygen as a green sustainable oxidant. Key advances include the use of readily available tert‐butyl nitrite (TBN) to promote radical annulation of 1,6‐enynes and easy‐to‐handle reaction conditions. Preliminary mechanistic studies including radical capture reactions
synthesis of quinoline derivatives by using dioxygen as an oxygen source is developed. By using visible light, the direct oxidativecyclization of aromatic enamines with alkynes or alkenes can be achieved at mild conditions with an aid of copper or palladium catalysts, and a variety of multisubstituted quinoline derivatives could be obtained in good to moderate yields under mild reaction conditions.