Gram-Scale Total Synthesis of (±)-Ibogamine

Abstract

We describe the gram-scale total synthesis of (±)-ibogamine in nine steps and 24% overall yield. The approach features a Mitsunobu fragment coupling and macrocyclic Friedel-Crafts alkylation to establish the nitrogen-containing core of ibogamine. A regio- and diastereoselective hydroboration allows for simultaneous formation of the tetrahydroazepine and isoquinuclidine ring systems via sulfonamide deprotection and concomitant intramolecular cyclization.