Dearomatization of Electron-Deficient Nitrogen Heterocycles via Cobalt-Catalyzed Asymmetric Cyclopropanation

The dearomatization of a series of electron-deficient nitrogen heterocycles has been achieved through a cobalt-catalyzed asymmetric cyclopropanation reaction. This reaction proceeds with high levels of enantio- and diastereo­selectivity to afford unique cyclopropanes that can be further functionalized to provide complex heterocyclic building blocks.