Green and facile synthesis of dihydropyrrol-2-ones and highly substituted piperidines using ethylenediammonium diformate (EDDF) as a reusable catalyst

Abstract

Extremely facile and efficient procedures have been developed for the synthesis of dihydropyrrol-2-ones and highly substituted piperidines. One-pot four-component reaction of amines, dialkyl acetylenedicarboxylates, and formaldehyde in the presence of ethylenediammonium diformate in ethanol under reflux conditions provides N-aryl-3-amino dihydropyrrol-2-one-4-carboxylates in good to high yields. The same conditions were found useful for the synthesis of highly substituted piperidines via a three (pseudo five)-component reaction of amines, aldehydes, and β-ketoesters. It is found that the catalyst is reusable and can be used up to five times without significant loss of its activity.