Et3N-catalyzed [3 + 2] annulation reaction of β-oxo-acrylamides with diethyl 2-oxomalonates: facile access to oxazolidin-4-one derivatives

A new and effective method for the [3 + 2] annulation of β-oxo-acrylamides with diethyl 2-oxomalonate, catalyzed by NEt3, has been developed to be carried out under mild reaction conditions. This approach offers a direct route to synthesize oxazolidin-4-one derivatives with yields ranging from 58% to 76%. The process is notable for being highly atom-efficient and operationally simple.