Direct regioisomer analysis of crude reaction mixtures <i>via</i> molecular rotational resonance (MRR) spectroscopy
作者:Leo A. Joyce、Danielle M. Schultz、Edward C. Sherer、Justin L. Neill、Reilly E. Sonstrom、Brooks H. Pate
DOI:10.1039/d0sc01853h
日期:——
Direct analyses of crude reaction mixtures have been carried out using molecularrotationalresonance (MRR) spectroscopy. Two examples are presented, a demonstration application in photocatalytic CH-arylation as well as generation of an intermediate in a natural product synthesis. In both cases, the reaction can proceed at more than one site, leading to a mixture of regioisomers that can be challenging
Cyclopropene Cycloadditions with Annulated Furans: Total Synthesis of (+)- and (−)-Frondosin B and (+)-Frondosin A
作者:E.Zachary Oblak、Michael D. VanHeyst、Jin Li、Andrew J. Wiemer、Dennis L. Wright
DOI:10.1021/ja413106t
日期:2014.3.19
The asymmetric total syntheses of the natural products (+)- and (-)-frondosin B and (+)-frondosin A are reported based on a diastereoselective cycloaddition between tetrabromocyclopropene and an annulated furan to provide a highly functionalized common building block. The bridged bicyclic intermediate could be stereo- and chemoselectively manipulated to produce the two structurally distinct members
天然产物 (+)- 和 (-)-frondosin B 和 (+)-frondosin A 的不对称全合成报告基于四溴环丙烯和环状呋喃之间的非对映选择性环加成,以提供高度功能化的通用构建块。可以对桥接双环中间体进行立体选择性和化学选择性操作,以产生 frodosins 的两个结构不同的成员。两种合成都具有区域选择性钯偶联反应和前所未有的膦介导的醚桥裂解。令人惊讶的是,计划中的 frondosin B 的对映选择性合成导致了天然产物的相反差向异构体,表明在 C8 处发生了不寻常的晚期立体反转。Frondosin A,而不是 frondosin B,被证明对几种 B 细胞系具有选择性的抗增殖活性。
Palladium-catalyzed couplings to nucleophilic heteroarenes: the total synthesis of (−)-frondosin B
作者:Chambers C. Hughes、Dirk Trauner
DOI:10.1016/j.tet.2004.07.041
日期:2004.10
The total synthesis of (-)-frondosin B, the enantiomer of naturally-occuring (+)-frondosin B, is described, wherein a palladium-catalyzed cyclization is used to establish the tetracyclic ring system of the natural product. (C) 2004 Elsevier Ltd. All rights reserved.