Evidence That Protons Can Be the Active Catalysts in Lewis Acid Mediated Hetero-Michael Addition Reactions
作者:Tobias C. Wabnitz、Jin-Quan Yu、Jonathan B. Spencer
DOI:10.1002/chem.200305407
日期:2004.1.23
mechanism of Lewis acid catalysed hetero-Michael addition reactions of weakly basic nucleophiles to alpha,beta-unsaturated ketones was investigated. Protons, rather than metal ions, were identified as the active catalysts. Other mechanisms have been ruled out by analyses of side products and of stoichiometric enone-catalyst mixtures and by the use of radical inhibitors. No evidence for the involvement
Metal halide hydrates as lewis acid catalysts for the conjugated friedel-crafts reactions of indoles and activated olefins
作者:Cristiane S. Schwalm、Marco Antonio Ceschi、Dennis Russowsky
DOI:10.1590/s0103-50532011000400003
日期:——
CrCl2·6H2O, CoCl2·6H2O e CeCl3·7H2O were investigated as mild Lewisacidscatalysts for the conjugate Friedel-Craftsreaction between indoles and activated olefins. The reactions were carried out with aliphatic unsaturated ketones over a period of days at room temperature, while chalcones reacted only under reflux conditions. The reactions with nitrostyrenes were either performed in solvent or under
Recyclable Sulfonated Amorphous Carbon Catalyzed Friedel-Crafts Alkylation of Indoles with α,β-Unsaturated Carbonyl Compounds in Water
作者:Jimei Ma、Simon Ng、Youjun Yong、Xiao-Zhou Luo、Xin Wang、Xue-Wei Liu
DOI:10.1002/asia.200900726
日期:2010.4.1
Green practice: A sulfonatedamorphouscarbon‐based solid acid derived from D‐glucose was synthesized. It was explored for its catalytic efficiency in Friedel–Crafts reactions of indoles with various α,β‐unsaturated carbonylcompounds in H2O or H2O/THF at room temperature. Moderate to excellent yields (67–96 %) were afforded. The catalyst could be recycled up to five times without any significant loss
绿色实践:衍生自D葡萄糖的磺化无定形碳基固体酸。探索了它在室温下在H 2 O或H 2 O / THF中吲哚与各种α,β-不饱和羰基化合物的吲哚的Friedel-Crafts反应中的催化效率。可提供中等至极好的收率(67–96%)。催化剂可以循环使用多达五次,而催化活性没有任何重大损失。
A New Amphiphilic Brønsted Acid as Catalyst for the Friedel-Crafts Reactions of Indoles in Water
作者:Yuan Cheng、Xiongyu Ou、Jimei Ma、Linhao Sun、Zhong-Hua Ma
DOI:10.1002/ejoc.201801612
日期:2019.1.10
A designed Brønsted acid enables Friedel–Crafts alkylation of indoles in water, whose hydrophobic aggregations of fluorocarbon chains, along with phenyl ring, protected acid sites from bulk water and enriched the substrates. The amphiphilic structure has been proven crucial for the high catalytic efficiency.
Copper-Catalyzed Synthesis of 2-Aminocarbazoles through Cascade C-C and C-N Bond Formation and Aromatization
作者:Xinlei Liu、Jiangkun Huang、Huibei Xu、Dandan Zhang、Qiu Sun、Ling He
DOI:10.1002/ejoc.201801297
日期:2019.2.7
The one‐pot synthesis of 2‐aminocarbanoles from 1‐(1H‐indole‐3‐yl)pentan‐3‐one through cascade C–C/C–N bond formation using ammonium carbonate as a nitrogen source and copper salt as a catalysis is reported.