New Pd‐Mediated Cascade Reactions for Synthesis of Novel Functionalized 1,3‐Oxazole‐Linked Quinoxaline Amines

Abstract

AbstractA number of functionalized 1,3‐oxazoles‐linked amine‐substituted quinoxalines were synthesized via one‐pot Pd‐catalyzed reactions in high yields. The cascade reactions of benzoyl chlorides, proprgylamine, and 3‐chloroquinoxaline‐2‐amines catalyzed by Pd–Cu in the presence of Et3N afforded new 3‐(amine‐substituted)quinoxalin‐2‐yl)(2‐aryl‐1,3‐oxazol‐5‐yl)methanone derivatives at 70 °C. The reactions commenced with the production of N‐propargylamides from benzoyl chlorides and proprgylamine, and proceeded through the Sonogashira coupling reactions with 3‐chloroquinoxaline‐2‐amines followed by the in situ ring closure of the resulting intermediates to give the target products. The use of primary 3‐chloroquioxaline‐2‐amines revealed that the cyclization step was regioselective and that pyrrolo[2,3‐b]quinoxalines were not prepared in this process.