A novel halogen-radical-promoted dearomative aza-spirocyclization of alkynylimines for the synthesis of 3-halo-spirocyclohexadienones is described. In this process, it is believed that a radical addition, 5-exo-trig cyclization, and dearomative aza-spirocyclization are involved. Easily available starting materials, mild conditions, and a wide substrate scope make this approach potentially useful.
Key words
halogen radical - dearomative aza-spirocyclization - alkynylimine - 3-halo-spirocyclohexadienone - 5-
exo-
trig cyclization