A tetradentate ligand enables iron-catalyzed asymmetric hydrogenation of ketones in a CO- or isocyanide-free fashion.

Abstract

We herein reported the design and synthesis of a ferrocene-based tetradentate ligand that is featured with modular synthesis and rigid skeleton. Its iron(II) complex facilitates asymmetric hydrogenation of ketones without the participation of extra strong-field ligand such as CO and isocyanide. Hydride donor LAH converted non-reactive Fe(II) species to reactive Fe(II) hydride species. With this catalyst, various chiral alcohols including the intermediate for montelukast could be prepared with satisfactory yields and enantioinduction.