Regio- and Diastereoselective Three-Component Reactions via Trapping of Ammonium Ylides with N-Alkylquinolinium Salts: Synthesis of Multisubstituted Tetra- and Dihydroquinoline Derivatives.

Pd(II)-catalyzed three-component reactions via trapping of ammonium ylides with N-alkylquinolinium salts are reported. These reactions provided polyfunctional polycyclic tetrahydroquinolines or 4-substituted 1,4-dihydroquinolines in excellent yields (89-99% and 89-98%, respectively) with high regioselectivities and moderate to good diastereoselectivities (up to 95:5 dr) under mild reaction conditions.