The biomimetic engineering of metal–organic frameworks with single-chiral-site precision for asymmetric hydrogenation†
Abstract
Asymmetric hydrogenation based on heterogeneous metal nanoparticles (NPs) has attracted extensive attention for the production of chiral chemicals due to its high conversion efficiency, simple product separation, and convenient catalyst regeneration. Nevertheless, its further practical application is still impeded by the leaching of expensive chiral ligands and by the associated extra purification costs that are caused by the weak absorption of the chiral ligands on the metal NPs. In contrast, chiral metal–organic frameworks (CMOFs) have been proposed to serve as metal NP supports and chirality inducers via biomimicry of the configuration of privileged natural cinchona alkaloids on the single-chiral-site level. Among the presented engineered isoreticular valine (Val)-, serine (Ser)-, and threonine (Thr)-derived CMOFs, the Thr-MOF-supported Pt nanoparticles (NPs) exhibit impressive enantioselectivity in the asymmetric hydrogenation of ethyl pyruvate (EP) in addition to inherently robust catalytic recyclability without the need to add either fresh chiral ligands or Pt NPs.