抄録
Mersicarpine was isolated from Kopsia fruticosa in 2004 by Kam and coworkers. Its unique structure, such as a seven-membered cyclic imine and an intricately oxidized indole moiety, attracted us to initiate synthetic studies on mersicarpine. To date, two racemic total syntheses of this natural product have been reported, though neither of which is applicable to an enantioselective synthesis. Herein, we report the first asymmetric total synthesis of mersicarpine. Our synthesis features Eschenmoser-Tanabe fragmentation via semicarbazone, Au-catalyzed indole synthesis, introduction of a nitrogen group by diazo coupling and construction of the seven-membered cyclic imine by intramolecular SN2 reaction and by following auto oxidation.
