Immobilization of heterobimetallic multifunctional asymmetric catalyst
Immobilization of an asymmetric AlLibis(binaphthoxide) catalyst (ALB) is described. The immobilized ALBs (poly-ALBs) are readily prepared from polymeric BINOL derivatives and LiAlH(4). The combined use of 9 mol % of BuLi with ca. 10 mol % (as a monomeric catalyst) of 6,6'-aryl-tethered poly-ALB gave the Michael adducts with up to 93% ee. After completion of the reaction, the insoluble catalyst was recovered in air and is reusable.
Arai
T
The Institute of Scientific and Industrial Research (ISIR), Osaka University, Ibaraki, Osaka 567-0047, Japan, and Department of Chemistry, University of Virginia, Charlottesville, Virginia 22901, USA.
Hu
QS
Zheng
XF
Pu
L
Sasai
H