Palladium-Catalyzed Carbonylative Sonogashira Coupling of Aryl Bromides via tert-Butyl Isocyanide Insertion

A simple and efficient palladium-catalyzed carbonylative Sonogashira coupling via tert-butyl isocyanide insertion has been developed, which demonstrates the utility of isocyanides in intermolecular C-C bond construction. This methodology provides a novel pathway for the synthesis of alkynyl imines which can undergo simple silica gel catalyzed hydrolysis to afford alkynones. The approach is tolerant of a wide range of substrates and applicable to library synthesis.