Cerium(III) Chloride Heptahydrate (CeCl3 · 7H2O) as an Efficient Enamination Catalyst in Aqueous Media
作者:M. M. Khodaei、A. R. Khosropour、M. Kookhazadeh
DOI:10.1007/s11178-005-0363-z
日期:2005.10
Cerium(III) chloride heptahydrate CeCl3 · H2O catalyzes enamination of β-dicarbonyl compounds with primary amines in aqueous medium at room temperature to afford the corresponding β-enamino ketones with high chemoselectivity.
The role of a Lewis acid in the Nenitzescu indole synthesis
作者:Valeriya S. Velezheva、Andrey I. Sokolov、Albert G. Kornienko、Konstantin A. Lyssenko、Yulia V. Nelyubina、Ivan A. Godovikov、Alexander S. Peregudov、Andrey F. Mironov
DOI:10.1016/j.tetlet.2008.09.087
日期:2008.12
A highly efficient Lewis acid-catalyzed method for the Nenitzescusynthesis of 5-hydroxyindoles with a range of substituents at N-1 and C-3 and symmetric 5,5′-dihydroxydiindoles has been developed. The amount of the catalyst (10–100 mol %) required depended on the nature of the enaminone component. It has been shown that Lewis acid plays a role in enaminone component activation through an enamine-ZnC12
Enamination of a wide various primary amines was successfully carried out in the presence of catalytic amounts of cerium chloride heptahydrate in ionic liquid and solvent-free conditions as 'green' media under mild reaction conditions.
2-Functionalized 4-nitroanilines were readily synthesized by ringtransformation using 3,5-dinitro-2-pyridone and enaminones prepared from 1,3-dicarbonyl compounds and amines. Modification of the amino group and the ortho-position could be achieved by simply changing the enaminones. Using this strategy, functional groups such as acetyl, benzoyl, and ethoxycarbonyl groups could be introduced into the
A novel and efficient methodology for the synthesis of 1,2,3-trisubstituted pyrroles by one-pot two-step reaction has been developed. The iodocyclization of a series of β-enamino esters followed by dehydroiodination, led to the formation of corresponding pyrroles. This approach provides an easy access to a wide range of 1,2,3-trisubstituted pyrroles.