Iridium-Catalyzed Asymmetric Hydrogenation of a-Fluoro Ketones via a Dynamic Kinetic Resolution Strategy

The discrimination of a fluorine atom from a hydrogen atom has been challenging in asymmetric catalysis. We herein report iridium-catalyzed hydrogenation of a-fluoro ketones using a strategy of dynamic kinetic resolution. Both enantiomeric and diastereomeric selectivities were satisfactory in the preparation of beta-fluoro alcohols. The DFT calculation revealed a C-F center dot center dot center dot Na charge-dipole interaction in the transition state of hydride transfer. This noncovalent interaction would be responsible for the diastereomeric control.