Palladium-Catalyzed Arylation of Trimethylsilyl Enolates of Esters and Imides. High Functional Group Tolerance and Stereoselective Synthesis of α-Aryl Carboxylic Acid Derivatives
作者:Xiaoxiang Liu、John F. Hartwig
DOI:10.1021/ja031544e
日期:2004.4.28
palladium-catalyzed arylation of trimethylsilyl enolates of esters and imides is reported. In the presence of ZnF2 or Zn(O-t-Bu)2 as an additive, the trimethylsilyl enolates of esters, including those bearing α-alkoxy derivatives, underwent arylation in high yield with high functional group tolerance. This arylation chemistry was extended to ester derivatives bearing chiral auxiliaries to form new tertiary stereocenters
报道了酯和酰亚胺的三甲基甲硅烷基烯醇化物的钯催化芳基化的一般程序。在 ZnF2 或 Zn(Ot-Bu)2 作为添加剂的存在下,酯的三甲基甲硅烷基烯醇化物,包括那些带有 α-烷氧基衍生物的酯,以高收率和高官能团耐受性进行芳基化。这种芳基化化学被扩展到带有手性助剂的酯衍生物以形成新的三级立体中心。带有 Evans 助剂的酰亚胺的芳基化以高达 90% de 的选择性进行。此外,Ley 开发的缩酮芳基化提供了具有优异非对映选择性(90 至 >98% de)的 α-芳基乙醇酸酯。该反应为合成对映纯 α-芳基-α-羟基酯提供了一条便利的途径。以 Zn(Ot-Bu)2 作为添加剂进行的反应在室温下进行,以提高与两种手性试剂的非对映选择性。机理研究表明,反应条件足够中性,可以观察到...