Ag(I)-Fesulphos-Catalyzed Enantioselective Synthesis of 3-Silylproline Derivatives
作者:Raghunath Chowdhury、Akhil K. Dubey、Sunil K. Ghosh
DOI:10.1021/acs.joc.8b02412
日期:2019.3.1
An efficient catalytic asymmetric 1,3-dipolar cycloaddition of N-benzylidineiminoglycinate-derived azomethine ylides to β-silylmethylene malonates catalyzed by a Ag(I)-Fesulphos complex has been developed, affording fully substituted 3-silylproline derivatives with an all carbon quaternary center. The silylproline derivatives were obtained in moderate-to-good yields (up to 81%) in high diastereoselectivities
已开发出由Ag(I)-Fesulphos配合物催化的N-苄基亚氨基次甘氨酸酯衍生的甲亚氨酸基团向β-甲硅烷基丙二酸酯的高效催化不对称1,3-偶极环加成反应,提供具有全碳季中心的完全取代的3-甲硅烷基脯氨酸衍生物。 。甲硅烷基脯氨酸衍生物以高至非对映选择性和对映选择性(dr高达95:5; er高达96:4)以中等至良好的产率(高达81%)获得。选定的3-甲硅烷基脯氨酸衍生物的Tamao-Fleming氧化不仅提供了一条有效的途径,而且提供了一条3-羟脯氨酸衍生物的最短途径,而偶氮甲胺内酯与常用的亚芳基/亚烷基丙二酸酯直接进行1,3-偶极环加成则无法获得。