Immobilization of Heterobimetallic Multifunctional Asymmetric Catalyst

Abstract
Immobilization of an asymmetric AlLibis(binaphthoxide) catalyst (ALB) is described. The immobilized ALBs (poly-ALBs) are readily prepared from polymeric BINOL derivatives and LiAlH4. 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.