Cobalt-Catalyzed Enantioselective Hydroboration of 1,1-Disubstituted Aryl Alkenes

We report the synthesis of cobalt complexes of novel iminopyridine–oxazoline (IPO) ligands and their application to the asymmetric hydroboration of 1,1-disubstituted aryl alkenes. The new catalysts afforded α-alkyl-β-pinacolatoboranes with exclusive regioselectivity in high yields with up to 99.5% ee. Furthermore, we have applied this method to an efficient synthesis of naproxen.