Asymmetric Hydrogenation of Pyridines: Enantioselective Synthesis of Nipecotic Acid Derivatives

An asymmetric hydrogenation process of 3‐substituted pyridine derivatives has been developed with the use of a Rh‐TangPhos complex as the catalyst. The whole process consists of an efficient partial hydrogenation of nicotinate and a subsequent highly enantioselective, Rh‐catalyzed, homogeneous hydrogenation. A series of chiral nipecotic acid derivatives have been synthesized. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)