Birds of a Feather—Asymmetric Organocatalysis Meets Asymmetric Transition Metal Catalysis

Ilya D Gridnev

doi:10.3390/catal12020214

Abstract

The results of recent studies on the mechanism of stereoinduction in asymmetric hydrogenation catalyzed by transition metal complexes suggest that hydrogen activation by metal atoms and the generation of enantioselectivity by organic ligands proceed independently. Hence, these reactions can be considered as variants of a cooperative organocatalytic reaction. This conclusion opens a broader view on rational catalyst design, suggesting that the structural ideas from different fields can be exploited reciprocally.

Highlights

More recent research actively carried out in the last 20 years brought extensive evidence that suggested instead that the role of transition metals in this process is restricted to the hydrogen activation, whereas the chiral ligand takes the responsibility for the stereoinduction [19,20]
The most striking example demonstrating the actual closeness of transition metals and organocatalysis is the Pd-catalyzed hydrogenation of the C=O bond with a heavily substituted SEGPHOS catalyst [38]
The above analysis of recent effective asymmetric hydrogenations demonstrates that metal atoms and chiral ligands work more or less independently in the processes of hydrogen activation and stereoinduction

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. The purpose of this essay is to illuminate experimental evidence that allows transitionmetal-catalyzed asymmetric catalytic reactions to be considered as a kind of cooperation catalysis, where the functions of chemical bonds’ activation by transition metals and stereoinduction effectuated by the organic ligand are separated in space and time. This viewpoint gives reasons for a more productive exchange of ideas on rational catalyst design in a broad area of asymmetric catalysis

Rh-Catalyzed Asymmetric Hydrogenation

Low-Temperature Reactions of Solvate Dihydrides with Prochiral Substrates

Computational Evidence

Artificial Catalysis Mimics Enzymatic Behavior

Conclusions