A number of N-substituted cyclic enediynes (azaenediynes) have been synthesized via Pd (0)-catalysed ene–yne coupling followed by N-alkylation. The simplest of them, a 10- membered monocyclic enediyne 1, underwent Bergman cyclization (BC) at 23° C with a half- life of 72 h. The kinetics of BC slowed down considerably by fusing a benzene ring onto the enediyne. Several novel bis (azaenediyne) s and bis (diazaenediyne) s 3–6 have been ...
