A facile synthesis of β-amino carbonyl compounds through an aza-Michael addition reaction under solvent-free conditions

Abstract

An efficient and eco-friendly process for the synthesis of β-amino carbonyl compounds was introduced in this paper. The oxanorbornene β-amino esters and β-enamine esters were successfully prepared from oxabornene and amines by using solvent-free aza-Michael addition reaction in the absence of any catalyst. Oxanorbornene β-amino esters were the major product at room temperature, but higher temperature (e.g. 90 °C) led to the formation of β-enamine esters. In addition, all of the target compounds were characterized by IR, ¹H NMR, ¹³C NMR, and HR-MS. A possible reaction pathway was also proposed.