Catalytic, Enantioselective Bifunctional Inverse Electron Demand Hetero-Diels−Alder Reactions of Ketene Enolates and <i>o</i>-Benzoquinone Diimides

Abstract

In this Communication, we report a system in which an achiral Lewis acid (activating the diene) works in concert with a chiral nucleophile (dienophile) to effect the first highly enantio- and regioselective catalytic inverse electron demand Diels-Alder [4 + 2] cycloaddition reaction to form biologically active quinoxalinones from ketene enolates and o-benzoquinone diimides in good to excellent yields with >99% ee.