Concise Synthesis of Isocoumarins through Rh-Catalyzed Direct Vinylene Annulation: Scope and Mechanistic Insight
作者:Gen Mihara、Koushik Ghosh、Yuji Nishii、Masahiro Miura
DOI:10.1021/acs.orglett.0c02112
日期:2020.7.17
subsequent C–C bond 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 direct construction 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。