A general and efficient method for synthesis of enaminones and enamino esters catalyzed by NbCls under solvent-free conditions

摘要

A general and simple procedure was developed for the synthesis of β-enaminones and β-enamino esters by reacting 1,3-dicarbonyl compounds with amines in the presence of catalytic amounts of niobium pentachloride. The reaction proceeds smoothly at room temperature under solvent-free conditions and leads to chemo- and regiose-lective formation of enamine derivatives in high to excellent yields.