B(C ₆ F ₅ ) ₃ ‐Catalyzed Reductive CC Bond Cleavage of Bisindolylmethanes

In this study, B(C 6 F 5 ) 3 ‐catalyzed reductive CC bond cleavage of bisindolylmethanes (BIMs) is reported as an efficient strategy for preparing C3‐alkylated indoles. In the presence of silane, B(C 6 F 5 ) 3 selectively activates Csp 2 ‐Csp 3 bonds of BIMs under mild conditions. Moreover, this sustainable process exhibits a broad substrate scope, highly functional group tolerance, and excellent regioselectivity. Preliminary mechanistic studies disclose that the formation of stabilized ion‐pair intermediates is crucial to achieving the desired transformation. Notably, the strategy provides a metal‐free alternative to transition metal catalysis, enabling the sustainable synthesis of valuable indole derivatives.