Photocatalytic (3+3) cycloaddition of arylaminocyclopropanes with nitrones: highly diastereoselective synthesis of 1,2-oxazinan-6-amine derivatives

Herein, we present an eosin Y-catalyzed visible-light-driven (3+3) cycloaddition of arylaminocyclopropanes with nitrones, enabling the highly diastereoselective synthesis of 1,2-oxazinan-6-amine derivatives under mild conditions. The reaction proceeds through a cyclopropane single-electron transfer (SET)-induced ring-opening to generate a carbon radical iminium intermediate that undergoes a subsequent (3+3) cycloaddition with nitrone. This protocol features high diastereoselectivity, accommodation of diversely substituted aryl cyclopropanes, and good functional group tolerance.