Synthesis of pyrrolo[1,2-a][1,6]benzodiazonines from pyrrolo[1,2-a][1,4] benzodiazepines and alkynes containing electron-acceptor substituents

It has been established that the reaction of pyrrolo[1,2-a][1,4] benzodiazepines with activated alkynes gives pyrrolo[1,2-a][1,6]benzodiazonines as the products of diazepine ring expansion. In the case of pyrrolo[1,2-a][1,4] benzodiazepine, substituted with formyl group at the pyrrole ring, both expansion and cleavage of the diazepine fragment can occur. © 2013 Springer Science+Business Media New York.