Towards Total Synthesis of Communesins and Perophoramidine: Unexpected Cascade Reaction of Michael-Mannich-Mannich Additions
作者:Yong Qin、Haoxing Wu、Xue Xiao
DOI:10.1055/s-0030-1259705
日期:2011.4
A new type of chiral amidinobenzodiene 5 was prepared from isatin in ten steps. While attempting to prepare the core structure from 5 and tryptamine derivative 17 via a hetero Diels-Alder reaction for the total synthesis of communesin and perophoramidine, we observed an unexpected three-step, one-pot cascade reaction of Michael-Manich-Manich additions. The cascade reaction between 5 and 17 yielded diasteromers 21a and 21b with a complex polycyclic skeleton of 2,3,4,5-diindolinohexahydropyrrole in 76% yield and a ratio of 3:1. The stereochemistry of 21a was confirmed by X-ray crystal-structural analysis.
通过十步反应,从靛红制备了一种新型的手性脒基苯并二烯5。在尝试通过异构Diels-Alder反应从5和色胺衍生物17制备核心结构,以实现共苷素和perophoramidine的全合成时,我们观察到了一种意外的Michael-Manich-Manich加成三步一锅级联反应。5和17之间的级联反应产生了具有2,3,4,5-二吲哚六氢吡咯复杂多环骨架的21a和21b非对映异构体,产率为76%,比例为3:1。21a的立体化学结构通过X射线晶体结构分析得到了证实。