Organocatalytic asymmetric conjugate addition of α-substituted cyanoacetates to maleimides
作者:Jin-Jia Wang、Xue-Jiao Dong、Wen-Tao Wei、Ming Yan
DOI:10.1016/j.tetasy.2011.04.009
日期:2011.3
The asymmetric conjugateaddition of α-substitutedcyanoacetates to N-substituted maleimides has been developed. A number of cinchona alkaloids and amine thioureas were evaluated as catalysts. Takemoto’s catalyst was found to be the most efficient for the transformation. Chiral succinimides with two adjacent quaternary and tertiary stereogenic carbon centers were obtained in good yields, enantioselectivities
Thiourea-Catalyzed Highly Diastereo- and Enantioselective Conjugate Additions of α-Substituted Cyanoacetates to Maleimides: Efficient Construction of Vicinal Quaternary- Tertiary Stereocenters
A highly diastereo‐ and enantioselective conjugateaddition of α‐substituted cyanoacetates to maleimides in the presence of a chiral bifunctional thiourea‐tertiary amine catalyst has been investigated for the first time. The procedure was capable of tolerating a relatively wide range of substrates with respect to α‐substituted cyanoacetates and maleimides, providing a series of substituted succinimidates