Enantioselective [3+2] annulation of 3-hydroxymaleimides with quinone monoimines

Enantioselective [3 + 2] annulation of 3-hydroxymaleimides with quinone monoimines was realized using a chiral phosphoric acid as a catalyst. Various novel succinimide fused dihydrobenzofurans bearing two continuous quaternary stereocenters were obtained in moderate to excellent yields (up to 99%) with moderate to excellent enantioselectivities (up to 99% ee). The absolute configuration of one product was assigned by X-ray crystal structural analysis and a plausible reaction mechanism was proposed.

Automated summary

In this study, enantioselective [3 + 2] annulation of 3-hydroxymaleimides with quinone monoimines was achieved using a chiral phosphoric acid catalyst. Various novel succinimide fused dihydrobenzofurans with two continuous quaternary stereocenters were obtained in moderate to excellent yields and enantioselectivities, with the absolute configuration of one product confirmed by X-ray crystal structural analysis.