Palladium‐Catalyzed Carbonylative Cyclization of Terminal Alkynes and Anilines to 3‐Substituted Maleimides

Abstract

AbstractHerein, we describe an interesting palladium‐catalyzed protocol for the carbonylative synthesis of 3‐substituted maleimides. By annulation of simple anilines with terminal alkynes under carbon monoxide pressure, the desired 3‐substituted maleimides can be obtained in 50–85% yields. Additionally, with the addition of phosphine ligand, maleic acid isoimide can be obtained from the same substrates as well. With the presence of K2S2O8, the obtained maleic acid isoimide can be completely transformed to the corresponding maleimide.magnified image