The homogenization of zirconium hydroxide phosphonate-supported ruthenium catalyst in asymmetric hydrogenation

A series of novel organosoluble zirconium phosphonate nanocomposites and their supported ruthenium catalysts with an organosoluble (20–142 mg mL− 1), mesoporous and layered structure were prepared. Due to organosolubilities in various organic solvents, the homogenization of the zirconium phosphonate-supported catalyst was realized in the asymmetric hydrogenation of ethyl pyruvate, in which supported ruthenium catalysts possessed higher conversion, isolated yield and enantioselectivity than corresponding homogeneous Ru(p-cymene)(S-Binap)Cl2 owing to site-isolation and confinement effect. After completing the reaction, the supported ruthenium catalyst can be recovered readily and quantitatively by addition of a poor solvent and centrifugation, and reused for five consecutive runs without significant loss in catalytic properties.

Graphical AbstractFigure optionsDownload full-size imageDownload as PowerPoint slideResearch Highlights►Organosoluble zirconium phosphonate-supported ruthenium catalysts were prepared. ►A catalytic reaction can be run under homogeneous conditions in organic solvents. ►Supported ruthenium catalyst was quantitatively recovered by solid/liquid separation. ►Better catalytic properties were observed owing to confinement effect.