Efficient Synthesis of Quinoxalines by I2/AgNO3 Co‐Promoted One‐Pot Annulation of Alkynes with 1,2‐Arylenediamines.

An efficient I2/AgNO3 co‐promoted one‐pot annulation of alkynes with 1,2‐arylenediamines into quinoxalines is reported. The reaction proceeded smoothly under mild conditions and rapidly generated quinoxalines (37 examples) in good to excellent yields (up to 83 %) with a good tolerance of functional groups. Moreover, π‐conjugated polycyclic quinoxaline derivatives could also be successfully synthesized by this one‐pot strategy. Furthermore, a gram‐scale reaction of the one‐pot reaction is also investigated. Finally, a plausible mechanism for the one‐pot reaction is proposed. [ABSTRACT FROM AUTHOR]