Iridium-Catalyzed Asymmetric Hydrogenation of 2‑Pyridyl Cyclic Imines: A Highly Enantioselective Approach to Nicotine Derivatives

A highly efficient asymmetric hydrogenation
of cyclic imines containing
a pyridyl moiety was established by using iridium catalysts with chiral
spiro phosphine-oxazoline ligands. This process will facilitate the
development of new nicotine-related pharmaceuticals. The introduction
of a substituent at the ortho position of the pyridyl
ring to reduce its coordinating ability ensures the success of the
hydrogenation and excellent enantioselectivity.