Chiralbisphosphazides complexed with lithium salts efficiently catalyze the direct enantioselective 1,4-addition of dialkyl malonates to acyclic enones. Spectroscopic studies on the stoichiometry of the bisphosphazide and lithium salt have indicated the formation of a 1:1 species as the active enantioselectivecatalyst. It is suggested that the catalyst generates a complex of the protonated phosphazide
Michael Addition of Active Methylene Compounds to α,β-Unsaturated Carbonyl Compounds under the Influence of Molecular Sieves in Dimethyl Sulfoxide
作者:Tomoko Kakinuma、Ryoichi Chiba、Takeshi Oriyama
DOI:10.1246/cl.2008.1204
日期:2008.12.5
The Michael addition of active methylene compounds to α,β-unsaturated carbonyl compounds in the presence of MS 4A in dimethyl sulfoxide proceeds smoothly to afford the corresponding 1,4-addition pr...