Asymmetric Michael addition of malonates to various α,β-unsaturated aldehydes using an organocatalyst derived from trans-4-hydroxyproline in MeOH proceeds smoothly to afford the corresponding Michael adducts in high yields with high to excellent enantioselectivities.
Enantioselective organocatalytic Michael addition of malonates to α,β-unsaturated aldehydes in water
作者:Anqi Ma、Shaolin Zhu、Dawei Ma
DOI:10.1016/j.tetlet.2008.03.051
日期:2008.5
The Michaeladdition of malonates to α,β-unsaturated aldehydes catalyzed by O-TMS protected diphenylprolinols and acetic acid in water occurs at 0 °C to rt. In most cases, the reaction runs to completion in less than 24 h. A wide range of aldehydes including β-aryl, β-alkyl and β-alkenyl acroleins are found to be compatible with these conditions, providing the corresponding adducts in good yields and
Highly enantioselective and recyclable organocatalytic Michael addition of malonates to α,β-unsaturated aldehydes in aqueous media
作者:Subrata K. Ghosh、Kritanjali Dhungana、Allan D. Headley、Bukuo Ni
DOI:10.1039/c2ob26248g
日期:——
in our lab, has been found to be very effective for the Michaeladdition reaction in aqueous solvents involving a wide range of α,β-unsaturated aldehydes and malonatederivatives. For the reactions studied, good to excellent yields (73%–96%) and high to excellent enantioselectivities (up to 97%) were obtained using this catalyst. In addition, the catalyst could be recycled up to four times with gradual