Reductive Heck coupling: an efficient approach toward the iboga alkaloids. Synthesis of ibogamine, epiibogamine and iboga analogs

A mild and efficient synthetic route to the iboga scaffold by employing reductive-Heck type annulation is described. The utility of this process is demonstrated by the direct access to the ibogamine, epiibogamine and iboga-analogs. The cyclization precursors were readily obtained from 2-iodoaniline by heteroannulation reaction with suitable alkynes followed by iodination.