Exploring Symmetry-Based Logic for a Synthesis of Palau’amine
作者:Qingyi Li、Paul Hurley、Hui Ding、Andrew G. Roberts、Radha Akella、Patrick G. Harran
DOI:10.1021/jo900755r
日期:2009.8.21
to palau’amine is described that exploits veiled symmetry in the structure. Bis-alkylidenes i have been prepared and found susceptible to halogenative desymmetrization using t-BuOCl. This oxidation forms the imbedded spirocyclopentane motif observed in the natural product. A host of atypical reactions and processes developed during these studies are discussed, as are plans for completing total syntheses
A bottom-up synthesis of lamellarinsG, J, L, and Z was achieved via one-pot halogen dance/Negishi coupling of a lithiated dibromopyrrole derivative. The easily accessible dibromopyrrole bearing an ester moiety underwent halogen dance smoothly at −78 °C within 10 min. The resultant α-pyrrolyllithium was transmetalated to the corresponding organozinc species, which was then coupled with an aryl iodide
层状蛋白 G、J、L 和 Z 的自下而上合成是通过锂化二溴吡咯衍生物的一锅卤素舞蹈/Negishi 偶联实现的。易于获得的带有酯部分的二溴吡咯在-78°C 下10 分钟内顺利进行了卤素舞蹈。得到的 α-吡咯锂被金属转移到相应的有机锌物质上,然后在催化钯的存在下与芳基碘化物偶联以提供完全取代的吡咯。随后进行卤素 - 锂交换以仅在靠近酯部分的 β 位置掺入硼酸酯基团。这种合成中间体允许逐步二芳基化,用于层状蛋白 G、J、L 和 Z 的全合成。