Iridium‐Catalyzed Enantioselective Hydrogenation of Alkenylboronic Esters

Choose the right ligand: An iridium complex derived from a phosphino–imidazoline ligand is a highly efficient catalyst for the asymmetric hydrogenation of terminal vinyl boronic esters (see scheme). On the other hand, trisubstituted alkenyl-boronates can be reduced with high activity and good to excellent enantioselectivity employing a pyridine–phosphinite ligand.