Photoredox-Catalyzed\nCarbamoyl Radical-Initiated Dearomative\nSpirocyclization To Access Spiro-Cyclohexadiene Oxindoles

The sustainable construction of spirocyclic compounds\nis important\nto the scientific community and the pharmaceutical industries. Herein,\nwe demonstrate a carbamoyl radical-initiated intramolecular dearomative\nspirocyclization to access the spiro-cyclohexadiene oxindoles under\nvisible light irradiation, which constitutes the first example of\naccessing the I-substituted derivatives that facilitate diversified\ntransformations. Additionally, the scalability, late-stage modification\nof drugs, and significant antitumor activity of the products demonstrate\nthe novel spirocyclic synthesis platform for expediting drug development.