Palladium-Catalyzed Cross-Coupling of Alkynyl Carboxylic Acids with Isocyanides: Solvent-Controlled Selective Synthesis of 5-Iminofuranones and 5-Iminopyrrolones

A novel palladium-catalyzed cyclization of alkynyl carboxylic acids with isocyanides has been successfully developed herein. The corresponding 5-iminofuranone or 5-iminopyrrolone derivatives were constructed in moderate to good yields which were well controlled by the solvents. These reactions proceed under simple and mild reaction conditions with high efficiency, and feature a wide substrate scope, readily available starting materials and easy operation.