A catalyst and method for performing a Michael addition reaction between a &bgr;-dicarbonyl compound with a cyclic or acyclic enone, where the catalyst comprises a substituted or unsubstituted lanthanum-linked BINOL complex, e.g. a (R,R)-La-linked-BINOL complex (1), are described.
1
The catalyst is stable in air, is readily separated from the reaction mixtures and may be reused if desired.
Polymer-supported linked-BINOL was synthesized to immobilize asymmetric catalysts with two BINOL units. The advantage of the polymer-supported linked-BINOL over randomly polymer-supported BINOL was confirmed by asymmetric Michael reaction. A novel polymer-supported La-Zn-linked-BINOL complex afforded the Michael adduct in good yield and moderate ee. (C) 2000 Elsevier Science Ltd. All rights reserved.