Enantioselective Total Synthesis of (+)-Lysergic Acid, (+)-Lysergol, and (+)-Isolysergol by Palladium-Catalyzed Domino Cyclization of Allenes Bearing Amino and Bromoindolyl Groups
作者:Shinsuke Inuki、Akira Iwata、Shinya Oishi、Nobutaka Fujii、Hiroaki Ohno
DOI:10.1021/jo102388e
日期:2011.4.1
Enantioselective total synthesis of the biologically important indole alkaloids (+)-lysergol, (+)-isolysergol, and (+)-lysergic acid is described. Key features of these total synthesis include (1) a facile synthesis of a chiral 1,3-amino alcohol via the Pd(0)- and In(I)-mediated reductive coupling reaction between l-serine-derived 2-ethynylaziridine and formaldehyde; (2) the Cr(II)/Ni(0)-mediated Nozaki−Hiyama−Kishi
描述了对生物重要的吲哚生物碱(+)-麦角酚,(+)-异麦角酚和(+)-麦角酸的对映选择性全合成。这些总合成的关键特征包括:(1)通过Pd(0)和In(I)介导的1-丝氨酸衍生的2-乙炔基氮丙啶与甲醛之间的还原性偶合反应轻松合成手性1,3-氨基醇; (2)吲哚-3-乙醛与碘炔的Cr(II)/ Ni(0)介导的Nozaki-Hiyama-Kishi(NHK)反应; (3)Pd(0)催化带有氨基和溴代吲哚基的丙二烯的多米诺环化反应。这种多米诺环化反应可以直接构建麦角生物碱骨架的C / D环系统,以及通过将烯丙基轴向手性转移到中心手性而创建C5立体中心。