Total synthesis of coriandrin and 7-demethylcoriandrin via a new synthesis of isocoumarins
摘要:
Indenone epoxides 8, prepared from the corresponding indenones, have been shown to undergo clean thermal rearrangement to give isocoumarins 10 in high yields. This synthesis of isocoumarins, when applied to oxaindacenone 7, resulted in the total synthesis of coriandrin (1). (C) 2000 Elsevier Science Ltd. All rights reserved.
Rhodium-Catalyzed Annulative Coupling Using Vinylene Carbonate as an Oxidizing Acetylene Surrogate
作者:Koushik Ghosh、Yuji Nishii、Masahiro Miura
DOI:10.1021/acscatal.9b04254
日期:2019.12.6
Transition-metal-catalyzed C–Hactivation and subsequent oxidative cyclization with alkynes has been a powerful tool for the synthesis of polycyclic aromatic compounds. Despite the substantial progress in this field, it is still a significant challenge to establish synthetic methodologies for the construction of nonsubstituted vinylene-fused aromatics. We herein report a Rh(III)-catalyzed C–H/N–H annulation with vinylene
subsequent C–Cbond formation have emerged as powerful synthetic tools for the synthesis of elaborate cyclic molecules. In this report, we introduce an efficient synthetic method of 3,4-unsubstituted isocoumarins adopting an electron-deficient CpERh complex as the catalyst. The use of vinylene carbonate as a vinylene transfer reagent enables the directconstruction of isocoumarins from readily available
惰性C–H键的过渡金属催化活化和随后的C–C键形成已成为合成精细环状分子的有力合成工具。在本报告中,我们介绍了一种有效的合成方法,该方法采用缺电子的Cp E Rh络合物作为催化剂来合成3,4-未取代的异香豆素。碳酸亚乙烯酯作为亚乙烯基转移试剂的使用使得可以从容易获得的苯甲酸直接构建异香豆素,而无需任何外部氧化剂和碱。通过计算分析评估反应机理,以发现催化循环内前所未有的“铑转移”事件。
Rhodium‐Catalyzed Direct Vinylene Annulation of Sulfoxonium Ylides and <i>N</i>‐carbamoylindoles with Vinylene Carbonate
作者:Jia‐Lin Song、Lin Xiao、Shao‐Yong Chen、Yi‐Chuan Zheng、Yan‐Zhi Liu、Shang‐Shi Zhang、Bing Shu
DOI:10.1002/adsc.202300135
日期:2023.5.12
In this study, Rh(III)-catalyzed C−H bifunctionalization and direct vinylene annulation of sulfoxonium ylides and N-carbamoylindoles with vinylenecarbonate was accomplished, which afforded a series of naphthalenones containing a β-ketosulfoxonium ylide moiety, isocoumarins, and pyrimidones. This protocol featured mild conditions, broad substrate scope, and functional-groups compatibility. In addition