Ru-Catalyzed Deoxygenative Aromatization of Succinimides and Oxindoles to Pyrroles and Indoles

Abstract

Deoxygenative aromatization of cyclic amides offers a distinct retrosynthetic strategy for accessing nitrogen-containing heteroarenes, yet the practical and efficient conversion of abundant amides remains a significant challenge. Herein, we report a ruthenium-catalyzed deoxygenative aromatization protocol for the streamlined transformation of succinimides and oxindoles into pyrroles and indoles. Employing Ru3(CO)12 (0.05‒0.1 mol%) and 1,1,3,3-tetramethyldisiloxane (TMDSO), this protocol enables direct access to the corresponding heteroarenes in good to high yields under mild reaction conditions. The method exhibits broad functional group tolerance and is applicable to late-stage modification of biologically relevant molecules. A gram-scale synthesis (10 g, TON up to 1900) and integration with Diels–Alder chemistry demonstrate the practicality of the method and its utility for constructing fused polycyclic pyrrole architectures.