Lewis Acid Promoted Oxonium Ion Driven Carboamination of Alkynes for the Synthesis of 4‑Alkoxy Quinolines

Lewis acid mediated
multisegment coupling cascade is designed for
the synthesis of densely substituted 4-alkoxy quinolines via an oxonium
ion triggered alkyne carboamination sequence involving C–C
and C–N bond formations. Cyclic ether fused-quinolines could
also be accessed using this fast, operationally simple, high yielding,
chemoselective and functional group tolerant method. Versatility and
utility of this methodology is demonstrated by postfunctionalization
of products obtained and its use in synthesis of potent drug molecules.