Pyrrole derivatives represent a very important class of heterocyclic compounds. 1 Among them, pyrroles annulated to other heterocycles via a C–N bond can be highlighted due to the broad spectrum of their bioactivity. The antitumor and antibiotic agent, mitomycin is a pyrrolo[1,2-a]indole derivative, whilst the anti-HIV agent castanospermine has an indolizidine scaffold; Erythrina alkaloids belong to pyrrolo[2,1-a]isoquinoline family; and the ...