Cyclopropenimine-Enabled Redox Control in Copper-Catalyzed Radical Cyclization to 3,3-Disubstituted Oxindoles.
Radical-mediated construction of all-carbon quaternary centers offers a powerful approach, yet its application to tertiary alkyl halides under mild conditions remains challenging, often due to the need to orchestrate multiple redox events within a single catalytic cycle. Herein, we report a cyclopropenimine-enabled cop...