of fire: A highly efficient totalsynthesis of the title compounds features a novel benzyne‐mediated one‐pot indoline formation/cross‐coupling sequence for the construction of a highly substituted key indoline intermediate. The peripheral substituents were then introduced onto the intermediate in a modular fashion to complete the total syntheses of dictyodendrin A and B.
In total and formal syntheses of dictyodendrins B, C, E, and F, the key step involved the direct construction of the pyrrolo[2,3‐c]carbazole core by the gold‐catalyzed annulation of a conjugated diyne with a pyrrole to form three bonds and two aromatic rings. The subsequent introduction of substituents at the C1 (Suzuki–Miyaura coupling), C2 (addition to an aldehyde), N3 (alkylation), and C5 positions
在双脱硫木糖醇B,C,E和F的全部和形式合成中,关键步骤涉及通过金催化的共轭二炔与吡咯的环化反应直接构建吡咯并[2,3- c ]咔唑核三个键和两个芳香环。随后在C1(Suzuki-Miyaura偶联),C2(加成醛),N3(烷基化)和C5位置(乌尔曼偶联)处引入取代基提供了不同的途径获得十碳五苯醚。
Total Synthesis of Dictyodendrins A–F by the Gold‐Catalyzed Cascade Cyclization of Conjugated Diyne with Pyrrole
The total synthesis of dictyodendrins A–F was achieved by using the gold(I)‐catalyzed annulation of a conjugated diyne with N‐Boc‐pyrrole for direct construction of the pyrrolo[2,3‐c]carbazole scaffold. Late‐stage functionalization of the resulting pyrrolo[2,3‐c]carbazole to introduce various substituents provided divergent access to dictyodendrins. Some dictyodendrin analogues exhibited inhibitory
dictyodendrins A-F的总合成是通过金(I)催化的共轭二炔与N -Boc-吡咯的环化反应直接构建吡咯并[2,3- c ]咔唑支架而实现的。所得吡咯并[2,3– c ]咔唑的后期官能化引入各种取代基提供了对十二碳四烯联苯醚的不同途径。一些双齿豆蔻甙类似物对CDK2 / CycA2和GSK3表现出抑制活性。
A Concise and Scalable Strategy for the Total Synthesis of Dictyodendrin B Based on Sequential CH Functionalization
作者:Andrew K. Pitts、Fionn O'Hara、Robert H. Snell、Matthew J. Gaunt
DOI:10.1002/anie.201500067
日期:2015.4.27
A sequentialCHfunctionalizationstrategy for the synthesis of the marine alkaloid dictyodendrinB is reported. Our synthesis begins from commercially available 4‐bromoindole and involves six direct functionalizations around the heteroarene core as part of a gram‐scalestrategy towards the natural product.