Ruthenium-Catalyzed Cycloisomerization of Aromatic Homo- and Bis-Homopropargylic Amines/Amides: Formation of Indoles, Dihydroisoquinolines and Dihydroquinolines

Ruthenium-catalyzed cycloisomerizations of aromatic homo- and bis-homopropargylic amines/amides efficiently afford indoles, dihydroisoquinolines and dihydroquinolines. These processes were regioselective (5- and 6-endo cyclizations) on using key Ru vinylidene intermediates. The presence of an amine/ammonium base-acid pair increased the rate of cyclization and facilitated the catalytic turnover.