A domino decarboxylative alkylation/annulation for the synthesis of pyrrolo-benzimidazolones

In this study, we report a novel, radical-promoted one-pot synthesis of pyrrolo-benzimidazolones (pyrrolo[1,2-a]benzimidazol-1-ones), involving the reaction of N-propiolyl-benzimidazole with aliphatic carboxylic acids in the presence of ammonium persulfate. A diverse range of aliphatic carboxylic acids as well as aryl N-propiolyl-benzimidazoles could participate in this oxidative domino reaction. Further transformations of the obtained pyrrolo-benzimidazolone were also demonstrated.