Diazoenals as 4[C]‐Reagents Toward Direct Synthesis of 2,2′‐Bis(indolyl)methanes From 2,2′‐Dipyrromethanes

Herein, we report a Rh(II)‐catalyzed double [4 + 2] benzannulation of diazoenals with 2,2′‐dipyrromethanes, providing direct access to biologically relevant 2,2′‐bis(indolyl)methanes. The transformation proceeds through an in situ generated Rh‐enalcarbenoid intermediate that serves as a 4[C] synthon, enabling regioselective C2‐functionalization of the pyrrole ring followed by intramolecular cyclization. This strategy represents the first example of 2,2′‐bis(indolyl)methanes synthesis that does not rely on indole precursors. By exploiting the unique reactivity of Rh‐enalcarbenoids, this methodology expands the synthetic toolbox for constructing indole‐based heterocyclic frameworks with potential applications in medicinal chemistry. The synthetic importance of double [4 + 2] benzannulation has been demonstrated by the one‐step synthesis of the biologically relevant 2,2′‐bis(indolyl)methane scaffold.