Rapid Synthesis of Fused N-Heterocycles by Transition-Metal-Free Electrophilic Amination of Arene CH Bonds
作者:Hongyin Gao、Qing-Long Xu、Muhammed Yousufuddin、Daniel H. Ess、László Kürti
DOI:10.1002/anie.201309973
日期:2014.3.3
disclose an efficient and operationally simple protocol for the preparation of fused N‐heterocycles starting from readily available 2‐nitrobiaryls and PhMgBr under mild conditions. More than two dozen N‐heterocycles, including two bioactive natural products, have been synthesized using this method. A stepwise electrophilic aromatic cyclization mechanism was proposed by DFT calculations.
Solvent-free synthesis of δ-carbolines/carbazoles from 3-nitro-2-phenylpyridines/2-nitrobiphenyl derivatives using DPPE as a reducing agent
作者:Haixia Peng、Xuxing Chen、Yanhong Chen、Qian He、Yuyuan Xie、Chunhao Yang
DOI:10.1016/j.tet.2011.06.027
日期:2011.8
A green and efficient preparation of functionalized delta-carbolines/carbazoles via reductive ring closure by 1,2-bis(dipenylphosphino)ethane under solvent-free conditions is described. The starting materials 3-nitro-2-phenylpyridines/2-nitrobiphenyl derivatives are readily prepared through Suzuki-Miyaura cross-coupling reaction from commercially available compounds. And the polar by-product ethane-1,2-diylbis(diphenylphosphine oxide) is easily removed from the relatively polar reaction mixture. Various substituted delta-carbolines/carbazoles are obtained in acceptable yields. It is particularly worth mentioning that substrates with electron-withdrawing groups (EWG) also give the desired products in good yield. (C) 2011 Elsevier Ltd. All rights reserved.