Studies on Lewis Acid-Catalysed Generation and Intermolecular Trapping of Chiral Stabilised Azomethine Ylids

Abstract

Preparation of the ylid (2) derived from 5(R)-phenylmorpholinone (1) in the presence of freshly prepared MgBr₂·Et₂O and dipolarophiles can lead to improved cycloaddition yields, with inverse diastereo- and regioselection compared to the corresponding uncatalysed reactions.