Ag-Catalyzed Switchable Synthesis of Site-Specifically Functionalized Pyrroles via Azafulvenium Intermediates.

Here, we present a versatile, silver-catalyzed multi-auto-tandem reaction involving enamines, alkynals, and nucleophiles, utilizing the highly reactive intermediate azafulvenium. This method allows for flexible and switchable regiodivergent reactions through either intermolecular or intramolecular nucleophilic attacks, which can be controlled by adjusting the catalytic conditions. A range of site-specific functionalized or polycyclic fused pyrrole products were efficiently produced with a high level of chemocontrol.