TBAI‐catalyzed, TBHP‐mediated Modular Three‐Component Cascade towards Highly Functionalized Pyrrole via [3+2] Annulation

A facile, one-pot sequential synthesis of highly substituted pyrrole employing TBAI/TBHP has been developed from readily available precursors. β-Enaminones generated in situ from β-ketoesters and primary amines react sequentially with electron-deficient alkynes via a radical pathway to form the penta-substituted pyrroles in moderate to good yields. This strategy for the synthesis of highly functionalized pyrroles can be scaled up and shows tolerance to a variety of amines.