Cobalt-Catalyzed Asymmetric Markovnikov Hydroboration of Styrenes

A cobalt-catalyzed asymmetric hydroboration of styrenes using an imidazoline phenyl picoliamide (ImPPA) ligand was first reported to deliver the valuable chiral secondary organoboronates with good functional tolerance and high enantioselectivity (up to >99% ee). This protocol is operationally simple without any activator. Particularly, this method can be applied in the asymmetric hydroboration of allylamine to afford 1,3-amino alcohol, which is a key intermediate for the synthesis of fluoxetine and atomoxetine. Furthermore, control experiments, isotopic labeling experiments, and qualitative and quantitative kinetic studies were also conducted to figure out the primary mechanism.