화학공학소재연구정보센터
Applied Catalysis A: General, Vol.425, 28-34, 2012
Recyclable copper catalysts based on ionic-tagged C-2-symmetric Indabox ligands and their application in asymmetric Henry reactions
New imidazolium/pyrrolidinium-tagged Indabox ligands were designed and prepared. Catalysts based on these ligands with Cu(OAc)(2)center dot H2O were applied to the asymmetric Henry reaction using various aldehydes and CH3NO2, the products were obtained in high enantioselectivity. Specifically, (R)-1-(2-methoxylphenyl)-2-nitroethanol was obtained in 94% ee in MeOH. Furthermore, the catalyst based on 7 could be recycled at least 12 times by simple wash without an obvious loss of activity or enantioselectivity. This catalytic procedure demonstrated the potential for catalyst recyclability in the asymmetric Henry reaction. Additionally, a theoretical mechanistic study was conducted to explain the origin of the enantioselectivity. (C) 2012 Elsevier B.V. All rights reserved.