Enzyme-Promoted Direct Asymmetric Michael Reaction by Using Protease from Streptomyces griseus
作者:Ling-Ling Wu、Ling-Po Li、Yang Xiang、Zhi Guan、Yan-Hong He
DOI:10.1007/s10562-017-2095-4
日期:2017.8
AbstractThe directasymmetric Michael addition of malonates and enones was promoted by protease from Streptomyces griseus for the first time. Yields of up to 84% with enantioselectivities of up to 98% enantiomeric excess (ee) were achieved under optimized conditions.Graphical AbstractProtease from Streptomyces griseus (SGP) was used for the first time as a biocatalyst in asymmetric Michael reaction of malonates
The Michael reaction of a dialkyl malonate to a cyclic enone using a chiral diamine/acid combination catalyst gave the desired Michael adduct in high yield with excellent enantiomeric excess in a protic solvent such as methanol and ethanol. The methanol molecule participates in a proton relay system in which the dialkyl malonate is activated through hydrogen bonding to afford the Michael adduct with
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.