Palladium-Catalyzed Intermolecular Aerobic Oxidative Cyclization of 2‑Ethynylanilines with Isocyanides: Regioselective Synthesis of 4‑Halo-2-aminoquinolines

Abstract

A robust and regioselective palladium-catalyzed intermolecular aerobic oxidative cyclization of 2-ethynylanilines with isocyanides to the synthesis of 4-halo-2-aminoquinolines is reported herein. The procedure constructs various 4-halo-2-aminoquinolines with moderate to excellent yields (47–94%) and broad substrates scope. Furthermore, this process can be easily extended to synthesis of various 6<i>H</i>-indolo­[2,3-<i>b</i>]­quinolines via an intramolecular Buchwald–Hartwig cross-coupling reaction in two-step one-pot manner