Abstract The cycloheptabindole scaffold is a privileged motif embedded in structures of many biologically active natural products. Herein, we report for the first time the assembly of this tricyclic system via a gold-catalyzed 7-exo-dig cyclization of acyclic 3-(5-hexynyl)indoles. This efficient transformation proceeds under very mild, neutral conditions and may serve as a key step in the synthesis of cycloheptabindole alkaloids. Further redox manipulations demonstrate the potential of this approach for application in the total synthesis of various indole alkaloids.
Trmcic et al. (Mon,) studied this question.