Evolution of two routes for asymmetric total synthesis of tetrahydroprotoberberine alkaloids

Abstract

Two synthetic routes have been developed for the asymmetric synthesis of tetrahydroprotoberberines, featuring installation of the asymmetry at an early stage of asymmetric redox-A³ reaction and the late stage of asymmetric Noyori asymmetric transfer hydrogenation, respectively. This work is filling the gap between racemic and asymmetric syntheses of tetrahydroprotoberberines enabled by redox-A³ reaction.