N‑Heterocyclic Carbene-Catalyzed Stereoselective Cascade Reaction: Synthesis of Functionalized Tetrahydroquinolines

The first N-heterocyclic carbene-catalyzed stereoselective aza-Michael–Michael–lactonization cascade reaction of 2′-aminophenylenones and 2-bromoenals for the construction of chiral functionalized tetrahydroquinolines with three consecutive stereogenic centers has been achieved in high yields (up to 98%) with excellent diastereo- (>25:1) and enantioselectivities (up to 98.7% ee).