3‑Alkylperoxy-3-cyano-oxindoles from 2‑Cyano-2-diazo‑N‑phenyl-acetamides via Cyclizing Carbene Insertion and Subsequent Radical Oxidation

A transition-metal-free one-pot sequence for the synthesis of 3-peroxy-substituted oxindoles from readily prepared 2-cyano-2-diazo-acetamides is reported. The two-step tandem process includes a highly efficient thermal intramolecular C–H-carbene insertion followed by a tetrabutyl­ammonium iodide (TBAI) catalyzed radical C3-peroxy-functionalization. The protocol provides easy access to a new class of 3-cyano-3-peroxy-disubstituted oxindoles. Useful transformations to amides and alcohols are demonstrated.