Synthesis of 1H‐Pyrrolo[1,2‐a]indoles via Lewis Acid‐Catalyzed Annulation of Propargylic Alcohols with 2‐Ethynylanilines

A novel highly efficient, environmentally benign Lewis acid‐catalyzed, and protection‐free protocol for the construction of valuable polycyclic products bearing a 1H‐pyrrolo[1,2‐a]indole scaffold is described, starting from readily available propargylic alcohols and 2‐ethynylanilines. The one‐pot transformation entails the cleavage of one C−O bond, and the construction of two C−N bonds and one C−C double bond. This unique operationally simple method is performed under mild conditions and in air, producing water as the only byproduct; it is scalable and demonstrates good functional group compatibility and broad scope.