Photoredox-Catalyzed Carbamoyl Radical-Initiated Dearomative Spirocyclization To Access Spiro-Cyclohexadiene Oxindoles.

The sustainable construction of spirocyclic compounds is important to the scientific community and the pharmaceutical industries. Herein, we demonstrate a carbamoyl radical-initiated intramolecular dearomative spirocyclization to access the spiro-cyclohexadiene oxindoles under visible light irradiation, which constitutes the first example of accessing the I-substituted derivatives that facilitate diversified transformations. Additionally, the scalability, late-stage modification of drugs, and significant antitumor activity of the products demonstrate the novel spirocyclic synthesis platform for expediting drug development.