Synthetic Studies of 7‑Oxygenated Aporphine Alkaloids: Preparation of (−)-Oliveroline, (−)-Nornuciferidine, and Derivatives

Abstract

7-Oxygenated aporphines <b>1</b>–<b>6</b> possessing anti-configurations have previously been reported. In order to explore their bioactivities, a synthesis was established by utilizing a diastereoselective reductive acid-mediated cyclization followed by palladium-catalyzed ortho-arylations. Moderate XPhos precatalyst loading (10 mol %) and short reaction times (30 min) were sufficient to mediate the arylations. Alkaloids <b>1</b>–<b>5</b> were successfully prepared, while (−)-artabonatine A was revised to syn-isomer <b>30</b>. Consequently, (−)-artabonatine E likely also has a syn-configuration (<b>31</b>)