Asymmetric Synthesis of β-Hydroxy Amino Acids via Aldol Reactions Catalyzed by Chiral Ammonium Salts
作者:Sashikumar Mettath、G. S. C. Srikanth、Benjamin S. Dangerfield、Steven L. Castle
DOI:10.1021/jo049283u
日期:2004.9.1
an effective catalyst for the synthesis of β-hydroxy α-amino acids via asymmetric aldol reactions under homogeneous conditions. The syn diastereomers are obtained in good ee, and aryl-substituted aliphatic aldehydes are the best substrates for the reaction. These results represent the highest ee's obtained to date in direct aldol reactions of glycine equivalents catalyzed by inexpensive, readily prepared
由Park and Jew开发的Cinchona生物碱衍生的手性铵盐可作为在均相条件下通过不对称羟醛反应合成β-羟基α-氨基酸的有效催化剂。顺式非对映异构体的收率很好,芳基取代的脂族醛是反应的最佳底物。这些结果代表了迄今为止由廉价,易于制备的手性铵盐催化的甘氨酸当量的直接羟醛直接醛醇缩合反应获得的最高ee值。