Kinetic Resolution of Ferrocenyl Halide Racemates via Palladium/Chiral Norbornene Cooperative Catalysis

Planar-chiral ferrocenes are privileged scaffolds in asymmetric catalysis, pharmaceutical chemistry, and functional materials. However, their enantioselective preparation remains a formidable challenge. Herein, we report a highly efficient kinetic resolution of racemic ferrocenyl halides enabled by palladium/chiral norbornene cooperative catalysis. This approach utilizes simple aryl iodides and olefins as resolution reagents to access both enantioenriched ferrocenyl iodides/bromides and arylferrocene derivatives with high enantioselectivities (up to 99% and 97% ee, respectively). The retained C–X bond in the recovered planar-chiral ferrocenyl halides serves as a versatile handle for downstream transformations, providing rapid access to a broad array of structurally diverse planar-chiral ferrocenes. Notably, the derived planar-chiral ferrocenyl phosphine ligands exhibit good performance in the Cu-catalyzed asymmetric [3 + 2] cycloaddition reaction. DFT calculations are performed to uncover the origin of enantiodiscrimination in the KR process.