Synthesis of 2-azaanthracenes via a sequential Sonogashira coupling/alkynyl imine-allenyl imine isomerization/aza-Diels-Alder/elimination-aromatization reaction.

An interesting sequential Sonogashira coupling/alkynyl imine-allenyl imine isomerization/aza-Diels-Alder/elimination-aromatization reaction, providing a facile synthesis of substituted 2-azaanthracenes from 1,6-diynes and imidoyl chlorides, is reported. The easy procedure accessing the products efficiently from readily available starting materials may imply a potential synthetic application.