- Double A3-Coupling of Primary Amines Catalysed by Gold Complexes
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A novel family of dipropargylamines has been synthesised in one pot through a double catalytic A3-coupling of five components. Cationic [AuI-L][SbF6] complexes (L=JohnPhos) are extremely active catalysts for the double A3-coupling of primary amines (aliphatic or aromatic), formaldehyde and trimethylsilylacetylene. Several reactions of LAu-amine complexes with organic reagents were studied and followed by NMR and HRMS (ESI) analyses, providing information about the reaction mechanism. Specifically, the role of the π-gold(I) acetylide complexes as active catalyst species was firmly confirmed. Most of the intermediates of this five-component coupling were identified by GC-MS spectrometry, lending support to the mechanistic proposal. In some cases, cationic amine-gold(I)-L complexes corresponding to the activated reagent or intermediate were isolated and characterised by single-crystal X-ray diffraction analysis, their spectroscopic properties were recorded, and their catalytic activity evaluated. Protic solvents influence the course of the reaction by effecting the double deprotection of dipropargylamines, providing a convenient route to dipropargylamines with double-deprotected silyl moieties. When NaOH is present in the reaction media, formation of cationic acetylide-dipropargylamine gold(I) and neutral hydroxide LAuOH complexes, respectively, as high and less active intermediate catalyst forms occur.
- Grirrane, Abdessamad,álvarez, Eleuterio,García, Hermenegildo,Corma, Avelino
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- Supported copper (I) catalyst from fish bone waste: An efficient, green and reusable catalyst for the click reaction toward N-substituted 1,2,3-TRIAZOLES
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An eco-efficient, green, and multi-gram procedure is presented for one-pot multicomponent synthesis of N-substituted 1,2,3-triazoles by using waste fishbone powders supported CuBr (FBPs-CuBr) as catalyst. FBPs-CuBr is found to be an efficient heterogeneous catalyst and a series of 1,2,3-triazoles are obtained in moderate to excellent yields in water under MW irradiation (70–98%). It can be separated conveniently by a simple filtration and reused at least seven consecutive runs with a slight drop in the product yields. Furthermore, the desired product still could be obtained in 80% yield when the scale of the reaction was increased to 40.0 mmol.
- Xiong, Xingquan,Tang, Zhongke,Sun, Zhaohong,Meng, Xiaoqing,Song, Sida,Quan, Zhilong
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