Copper-Catalyzed Cascade Reaction via Intramolecular Hydroamination Cyclization of Homopropargylic Amines and Intermolecular Povarov Reaction with Imines

A new one-pot cascade
reaction of homopropargylic amines with simple
imines is developed in the presence of Cu­(OTf)2 and affords
a series of hexahydro-1H-pyrrolo­[3,2-c]­quinoline derivatives in good to high yields. This reaction proceeds
through an intramolecular hydroamination cyclization of homopropargylic
amine to generate a highly reactive dihydropyrrole intermediate in
situ. It subsequently reacts with imine via an intermolecular inverse-electron-demand
aza-Diels–Alder reaction and a 1,3-H shift to give the fused
pyrroloquinoline structures, forming two new C–C bonds and
one C–N bond and one N–H bond.