Metal‐Free Oxidative Annulation/Cyclization of 1,6‐Enynes for the Synthesis of 4‐Carbonylquinolines

Abstract Herein we report on the development of a metal‐free oxidative annulation 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 and isotope labelling experiments are also conducted. magnified image