Palladium-Catalyzed Cascade Heck Cyclization To Access Bisindoles.

A novel strategy for intercepting the σ-alkylpalladium species generated via a Heck reaction, enabling a palladium-catalyzed cyclization of o-ethynylanilines, has been described. This direct and operationally simple protocol provided a fundamental platform to synthesize bisindoles with high efficiency, involving one C-N bond and two C-C bond formations.