Helical peptide foldamer catalyzed Michael addition reactions of nitroalkane or dialkyl malonate to α,β-unsaturated ketones are reported along with the mechanistic considerations of the enantio-induction. A wide variety of α,β-unsaturated ketones, including β-aryl, β-alkyl enones, and cyclic enones, were found to be catalyzed by the helical peptide to give Michael adducts with high enantioselectivities
Highly enantioselective catalytic Michael reaction of α-substituted malonates using La-linked-BINOL complex in the presence of HFIP (1,1,1,3,3,3-hexafluoroisopropanol)
作者:Ryo Takita、Takashi Ohshima、Masakatsu Shibasaki
DOI:10.1016/s0040-4039(02)00882-1
日期:2002.5
conditions, the catalyticasymmetricMichaelreaction of a variety of α-substituted malonates proceeded successfully in high yield (up to 93%) and excellent enantiomeric excess (up to 99% ee). The addition of HFIP was also effective for the reaction of nonsubstituted malonates. In this case, 5 mol% of the La-linked-BINOLcomplex was sufficient for completion of the reaction in approximately 24 h. Moreover
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
Catalysis of the Michael Addition Reaction by Late Transition Metal Complexes of BINOL-Derived Salens
作者:Venkatachalam Annamalai、Erin F. DiMauro、Patrick J. Carroll、Marisa C. Kozlowski
DOI:10.1021/jo025993t
日期:2003.3.1
basic sites. These unique complexes have been shown to catalyze the Michael reaction of dibenzyl malonate and cyclohexenone with good selectivity (up to 90% ee) and moderate yield (up to 79% yield). These catalysts are also effective in the Michael reaction between other enones and malonates. Kinetic data show that the reaction is first order in the Ni*Cs-BINOL-salen catalyst. Further experiments probed