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.