Assembly of C3a-Peroxylated Pyrroloindolines via Interrupted Witkop Oxidation

The first synthetically useful interrupted Witkop oxidation has been disclosed through a radical triggered oxidative peroxycyclization of tryptamine derivatives, using a TBAI/TBHP catalytic system. This differs from known tryptophan oxidations, which typically cleave the 2,3-double bond. Upon one-pot reduction, this system renders an easy access to structurally distinct peroxypyrroloindoles, which are demonstrated to be useful precursors in various downstream synthetic elaborations.