Efficient and Rapid Stereoselective Synthesis of <i>trans</i>-4,5-Diaminocyclopent-2-enones by Acidic Ionic Liquid under Solvent-free Conditions

Abstract

Abstract Acidic ionic liquid 1-methylimidazolium tetrafluoroborate [HMim]+[BF4]−, was successfully employed as a reusable catalyst for the reaction of furfural and secondary amines to yield 4,5-diaminocyclopent-2-enones exclusively as trans diastereomer in the absence of solvent. The inherent Brønsted acidity and high polarity of ionic liquid resulted in the significant enhancement in the reaction rate.