Total Synthesis and Structural Refinement of the Cyclic Tripyrrole Pigment Nonylprodigiosin
作者:Alois Fürstner、Jaroslaw Grabowski、Christian W. Lehmann
DOI:10.1021/jo991021i
日期:1999.10.1
total synthesis of the cyclic prodigiosin derivative 4 is described, which constitutes a potential lead compound for the development of immunosuppressive agents. The key steps of this approach comprise a palladium-catalyzed Suzuki cross coupling reaction of the rather unstable pyrrole boronic acid derivative 17 with the electron rich pyrrolyl triflate 15 followed by a ring-closing metathesis reaction
描述了环状prodigiosin衍生物4的第一个全合成,它构成了开发免疫抑制剂的潜在先导化合物。该方法的关键步骤包括相当不稳定的吡咯硼酸衍生物17与富电子吡咯基三氟甲磺酸酯15的钯催化Suzuki交叉偶联反应,然后是所得二烯的闭环易位反应(RCM),形成大环靶分子环。通过使用茚基钌配合物21作为预催化剂可以最好地实现这种转化。如此形成的产物18.HCl的X射线数据表明,互变异构体形式B正确描述了该生物碱杂芳族链段内的电子分布,