Cobalt-Catalyzed Regioselective Synthesis of Pyrrolidinone Derivatives by Reductive Coupling of Nitriles and Acrylamides

A convenient and highly regioselective method for the synthesis of 5-methylenepyrrolidinone derivatives from various nitrites and acrylamides via a cobalt-catalyzed reductive coupling reaction is described. A possible mechanism that involves the formation of a cobaltaazacyclopentene intermediate from nitrite and acrylamide, protonation, keto-amide cyclization, and dehydration is proposed.