Rhodium-Catalyzed Enantioselective Vinylogous Addition of Enol Ethers to Vinyldiazoacetates
作者:Austin G. Smith、Huw M. L. Davies
DOI:10.1021/ja3092399
日期:2012.11.7
A highly asymmetric vinylogous addition of acyclic silyl enol ethers to siloxyvinyldiazoacetate is described. The reaction features a diastereoselective 1,4-siloxy group migration event. Products are obtained in up to 97% ee. When more sterically crowded silyl enol ethers are employed, an enantioselective formal [3+2] cycloaddition becomes the dominant reaction pathway. Control experiments reveal the
描述了无环甲硅烷基烯醇醚与甲硅烷氧基乙烯基重氮乙酸酯的高度不对称乙烯基加成。该反应具有非对映选择性 1,4-甲硅烷氧基迁移事件。产品的 ee 高达 97%。当使用空间上更拥挤的甲硅烷基烯醇醚时,对映选择性形式的 [3+2] 环加成成为主要的反应途径。对照实验表明 (Z)-烯烃几何结构对于高水平的对映控制至关重要。