Acid-Promoted Aza-Cyclization versus π-Cyclization of N-Acyliminium Species into Fused Pyrrolo[1,2-a]imidazolones and Pyrrolo[2,1-a]isoquinolinones - Fleury, Jean-François; Netchitaïlo, Pierre; Daïch, Adam (Synlett, 2011)