Access to Enantioenriched β‐Hydroxy gem‐Difluorinated Heterocyclic and Acyclic Derivatives through Rh(III)‐Catalyzed Asymmetric Transfer Hydrogenation

Abstract

AbstractWe report a process to access a variety of enantioenriched α‐gem‐difluorinated alcohols. A Rh(III)‐catalyzed asymmetric transfer hydrogenation method was developed in 85–98% yields and enantiomeric excesses ranging from 52% to >99%. The reduction proceeds under mild conditions with a range of difluorinated molecules including 3,3‐difluorochromanone, 3,3‐difluorothiochromanone, 3,3‐difluoro‐dihydroquinolinone and α‐difluorinated β‐ketosulfone derivatives to provide the desired enantioenriched difluorinated alcohols which are valuable fluorinated building blocks.