Mild Direct Single-Step Conversion of Propargyl Amines to Highly Substituted 3-Pyrrolin-2-ones

Pyrrolinones are frequently found in biologically active natural products and pharmaceuticals. As such, their synthesis has been the focus of several methodological studies. Described herein is a synthetic method for the direct conversion of terminal or arylated propargyl amines to 3-pyrrolin-2-ones utilizing a malonyl chloride and an amine base at a low temperature. It is postulated that the key intermediate is an ammonium enolate generated during the initial premixing of the amine base and malonyl chloride.