Palladium-Catalyzed Three-Component Reaction of Propargyl Carbonates, Isocyanides, and Alcohols or Water: Switchable Synthesis of Pyrroles and Its Bicyclic Analogues
详细信息 查看全文
- 作者：Guanyinsheng Qiu ; Qian Wang ; Jieping Zhu
- 刊名：Organic Letters
- 出版年：2017
- 出版时间：January 6, 2017
- 年：2017
- 卷：19
- 期：1
- 页码：270-273
- 全文大小：398K
- ISSN：1523-7052
文摘
In the presence of a catalytic amount of Pd(OAc)2 and a stoichiometric amount of tert-butylamine, the reaction of propargyl carbonates, isocyanides, and alcohols afforded polysubstituted aminopyrroles in good yields. Using water as a nucleophile instead of alcohol, the same reaction provided 1,4-dihydro-6H-furo[3,4-b]pyrrol-6-imines. A triple isocyanide insertion to the hypothetic (σ-allenyl)palladium(II) intermediate was involved in these ABC3-type multicomponent reactions. The key role of tert-butylamine was accounted for by its reaction with in situ generated carbon dioxide to form the carbamic acid, which in turn served as a nucleophile to trap the nitrilium intermediate.