Heterogeneous asymmetric hydrogenation of aromatic ketones enhanced by silanols on highly monodispersed silica spheres

• The asymmetric hydrogenation of aromatic ketones was enhanced by silanols.
• > 99.9% ee and > 99% conversion were obtained.
• A proposed H-bonding was speculated and proved by FTIR.
• With the silanols increasing, the activity of hydrogenation increased.

A triphenylphosphine-stabilized Ir/SiO2 catalyst modified by a chiral diamine was synthesized with four silica spheres as support for the asymmetric hydrogenation of aromatic ketones. The H-bond between substrate and silanols and the interaction between substrate and modifier commonly affected the steric configuration of asymmetric hydrogenation of aromatic ketones. With the silanols increasing, the activity of asymmetric hydrogenation significantly increased. This is the first report of heterogeneous asymmetric hydrogenation of aromatic ketones enhanced by silanols on highly monodispersed silica spheres with > 99.9% ee and > 99% conversion.

This is the first report of the heterogeneous asymmetric hydrogenation of simple aromatic ketones enhanced by silanols. With the silanols increasing, the enantioselectivity and activity increased. > 99.9% ee and > 99% conversion were obtained.Figure optionsDownload as PowerPoint slide