Highly diastereo- and enantioselective reactions of enecarbamates with an aldehyde
作者:Ryosuke Matsubara、Paulo Vital、Yoshitaka Nakamura、Hiroshi Kiyohara、Shū Kobayashi
DOI:10.1016/j.tet.2004.07.045
日期:2004.10
Catalytic asymmetric addition reactions of enecarbamates with ethyl glyoxylate have been developed using CuClO4·4CH3CN and a diimine ligand as the catalyst. Highly diastereo- and enantioselective addition reactions of α-mono-substituted enecarbamates have been also achieved. These reactions afforded the corresponding adducts with high selectivity; that is, syn adducts from Z-enecarbamates and anti
使用CuClO 4 ·4CH 3 CN和二亚胺配体作为催化剂,开发了氨基甲酸酯与乙醛酸乙酯的催化不对称加成反应。还已经实现了α-单取代的烯甲酰胺的高度非对映和对映选择性的加成反应。这些反应提供了具有高选择性的相应的加合物。即,顺式从加合物ž -enecarbamates和反从加合物Ë-烯氨基甲酸酯。提出的反应机理是氮杂-烯类途径,其中烯甲氨基甲酸酯的NH基团的质子起着重要作用,不仅对于加速反应而且对于提供适合于高选择性手性诱导的过渡态都是重要的。