Half-Sandwich Ru(II) Complexes Featuring Metal-Centered Chirality: Configurational Stabilization by Ligand Design, Preparation via Kinetic Resolution, and Application in Asymmetric Catalysis
Abstract
While it is well established that half-sandwich Ru(II) complexes possess metal-centered chirality, effective strategies to leverage their metal-centered chirality toward asymmetric synthesis have been challenging due to the configurational lability of the metal stereocenters. The metal-centered chirality is typically mediated by enantiopure ligands, which occupy a relatively narrow chemical space compared to their achiral counterparts. We demonstrate that achiral ligands can be used to access chiral-at-ruthenium half-sandwich complexes with exceptionally high configurational stability. Key to success is the introduction of a rigid bidentate ligand with a minimized dihedral angle between the pyridyl and phenolic moieties, which proved effective for preventing racemization. Computational studies revealed the energetic factors contributing to the exceptional configurational stability enabled by the rigid and planar structure of the successful ligand design. These optically active chiral-at-ruthenium complexes incorporating aldehyde moieties were obtained by NHC-catalyzed kinetic resolution with excellent selectivities (s-factor up to >200, ee up to 99%). We further demonstrate that they are highly effective chiral aldehyde catalysts for the asymmetric 1,6-conjugate addition of glycine ester and para-quinone methide.
Repository Citation
Liang, Hui, Gabriel N. Morais, Gang Chen, et al. 2025. "Half-Sandwich Ru(II) Complexes Featuring Metal-Centered Chirality: Configurational Stabilization by Ligand Design, Preparation via Kinetic Resolution, and Application in Asymmetric Catalysis." Journal of the American Chemical Society 147(8): 6825-6834.
Publisher
American Chemical Society
Publication Date
2-12-2025
Publication Title
Journal of the American Chemical Society
Department
Chemistry and Biochemistry
Document Type
Article
DOI
https://doi.org/10.1021/jacs.4c16928
Keywords
Chelating diphosphines, Transfer hydrogenation, Amino-alcohols, CP ligands, Aldehydes, Ketones, Stereocenter, Backbone, Family
Language
English
Format
text
