Base-Promoted Synthesis of 3-Alkenyl-2-pyridones from N-Propargyl-β-enaminones and Aryl Aldehydes

Main observation and conclusion In this article,we report a base-promoted sequential cyclization/aldol-type condensation/isomerization cascade reaction of N-propargyl-β-enaminones with aryl aldehydes.The key step in this protocol is the generation of 1,4-oxazepine anions from N-propargyl-β-enaminones under basic conditions,which are captured by aryl aldehydes.The method allows the formation of one pyridone core and one C—C double bond in“one pot”,and the preparation of a variety of densely decorated pyridone derivatives in moderate to good yields with broad functional group tolerance.