An efficient iron-promoted alkylation of indoles with enamides has been accomplished under mild reaction conditions. The reaction proceeded with remarkable regioselectivity leading exclusively to substitution by indoles at α-position of enamides.
Friedel-Crafts Alkylation of Indoles by tert-Enamides in Acetic Acid
作者:Xiao-Ping Xu、Shun-Jun Ji、Ying Zhang、Jing Jiang、Xue-Qiang Chu、Ran Jiang、Dan-Hua Li
DOI:10.1055/s-0031-1290605
日期:2012.3
In acetic acid, Friedel-Crafts alkylation of indoles by tert-enamides proceeded effectively in the absence of any catalyst to afford the pharmacologically and biologically active 2-oxo-1-pyrrolidine derivatives in moderate to good yields. The mechanistic study based on the NMR and HRMS analysis shows that the reaction was promoted by acid catalysis. The hydrogen-bond interaction between tert-enamides and AcOH may also be responsible for the reaction.
Recyclable NaHSO4 catalyzed alkylation of tert-enamides with indoles or amines in water: facile construction of pharmaceutically analogous bis-alkaloid scaffolds
作者:Xue-Qiang Chu、Shun-Yi Wang、Shun-Jun Ji
DOI:10.1039/c3ra40833g
日期:——
An efficient sodium hydrogen sulfate catalyzed alkylation of indoles or amines with tertiary enamides has been accomplished in water, affording the pharmacologically and biologically active 2-oxo-1-pyrrolidine derivatives in moderate to excellent yields. The key to our success is the use of NaHSO4 as a low loading, inexpensive, green and recyclable catalyst and the reactions could be scaled up to gram level.
Ferric(III) Nitrate: An Efficient Catalyst for the Regioselective Friedel-Crafts Reactions of Indoles and tert-Enamides in Water
作者:Ran Jiang、Xiao-Jin Wu、Xu Zhu、Xiao-Ping Xu、Shun-Jun Ji
DOI:10.1002/ejoc.201000994
日期:2010.11
The ferric nitrate catalyzed Friedel–Crafts reactions of various indoles and tertiary enamides, which proceed in water at room temperature, are demonstrated for an efficient, atom-economical and environmentally friendly route to produce indole derivatives under mild conditions. Based on experimental data and mechanistic studies, the iron(III) ion was found to activate the electron-rich C=C bond with
Direct alkylation of indoles and amines by tert-enamides: facile access to pharmaceutically active 2-oxo-1-pyrrolidine analogues
作者:Ran Jiang、Hai-Yan Xu、Xiao-Ping Xu、Xue-Qiang Chu、Shun-Jun Ji
DOI:10.1039/c1ob05546a
日期:——
Direct alkylation of indoles and amines by tertiary enamides for the synthesis of pharmaceutically active 2-oxo-1-pyrrolidine analogues was described. With only a 0.5 mol% catalyst loading, molecular iodine was demonstrated to be efficiently enough to promote the reaction under neat condition. Only Markovnikov addition product was obtained indicating that the reactions proceeded with excellent regioselectivity.