Bisoxazoline-Lewis Acid-Catalyzed Direct-Electron Demand <i>oxo</i>-Hetero-Diels−Alder Reactions of <i>N</i>-Oxy-pyridine Aldehyde and Ketone Derivatives

Abstract

A general catalytic oxo-hetero-Diels-Alder reaction for pro-chiral aldehyde and ketone N-oxy-pyridines is presented. The catalytic and asymmetric oxo-hetero-Diels-Alder reaction of electron-rich dienes with N-oxy-pyridine-2-carbaldehyde and ketone derivatives, catalyzed by chiral copper(II)-bisoxazoline complexes, gives optically active six-membered oxygen heterocycles in moderate to good yields and with excellent enantioselectivities.