Gold-Catalyzed Bicyclic Annulations of N‑(o‑Alkynylphenyl)imines with α‑Diazo Esters to Form 5,6-Dihydroindolo[2,1‑a]isoquinolines

One-pot synthesis of 5,6-dihydroindolo­[2,1-a]­isoquinolines from gold-catalyzed annulations between N-(o-alkynylphenyl)­imines and α-diazo esters is described. This cascade reaction involves an initial attack of the diazo ester at the imine to form cis-aziridine, followed by stereoselective [3 + 3]-annulations with the tethered arylalkyne. We have employed this new catalysis to prepare one bioactive 5,6-dihydroindolo­[2,1-a]­isoquinoline molecule.