Efficient heterogeneous asymmetric transfer hydrogenation of ketones using highly recyclable and accessible silica-immobilized Ru-TsDPEN catalysts.
[reaction: see text] Chiral Ru-TsDPEN [N-(p-toluenesulfonyl)-1,2-diphenylethylenediamine]-derived catalysts were first successfully immobilized onto amorphous silica gel and mesoporous silicas of MCM-41 and SBA-15 by an easily accessible approach. The catalyst immobilized on silica gel demonstrated remarkably high catalytic activities and excellent enantioselectivities (up to >99% ee) for the heterogeneous asymmetric transfer hydrogenation of various ketones. Particularly, the catalyst could be readily recovered and reused in multiple consecutive catalytic runs (up to 10 uses) with the completely maintained enantioselectivity.
Liu
Pei Nian
PN
Department of Chemistry and State Key Laboratory of Applied Organic Chemistry Lanzhou University, Lanzhou 730000, PR China.
Gu
Pei Ming
PM
Wang
Fei
F
Tu
Yong Qiang
YQ