| Chemical industry plays a key role in the development of ecnomy. However,it brings much pollution. The organic solvents is the main pollution source in chemical industry. Thus, many chemists have paid much attention to developt novel reactioin medium to replace the traditional organic solvents. Ionic liquids, due to their uinique properties such as good solvating ability, negligible vapor pressure, variable polarity, nonflammability and recyclability, have attracted considerable attention as green, economic, alternative reaction medium as well as high efficient catalysts.DBU(1,8-diazabicyclo[5.4.0]undec-7-ene)has some special properties and Russian scientist developed a series of inert ionic liquids based on DBU. We want to develop task-specific ionic liquids derived from DBU. We synthesized five DBU-based task-specific ionic liquids by simple neutralization reaction of DBU and five carboxyl acids, trifluoroacetic acid, acetic acid, lactic acid, propionic acid and butyric acid. The all five ionic liquids [DBU][Tfa], [DBU][Ac], [DBU][Lac], [DBU][n-Pr], and [DBU][n-Bu] are liquids at room temperature. They were characterised by NMR spectrum and elemental analysis. And also their densities, viscosities, pH values, miscibilities with different organic solvents, heat stability were studied.The paper used the five novel ionic liquids as catalysts for aza-Michael addition with aliphatic amines as donors. The reaction conditions and results are as follows: efficient catalyst is [DBU] [Ac] was the best catalyst (0.3 mmol),1 mmol aliphatic amine,1.3 mmol Michael acceptor, reaction temperature (25℃), reaction time (0.5-14 h), product yields (65-95%). with the high reaction rate and adduct yield. The Michael donors include dibenzylamine,benzylamine, morpholine, peperidine and pyarzole. Michael acceptors include various vinyl esters, acrylonitrile, and acrylamide. It is of interest to note that when imidazole as Michael donor were treated with methyl acrylate, no Michael product was detected with the formation of unknown product. However,2-isopropylimidazole could react with methyl acrylate. From the above, steric bulkiness of reagent can assist to formate the Michael adduct and is detrimental to unknown reaction. Next, the paper applied the five ionic liquids as catalysts for aza-Michael addition of aromatic amines to a,β-unsaturated ketones under solvent-free conditions. Among the five ionic liquids, [DBU][Lac] has the excellent catalytic efficiency. No bis-adduct was detected. Reaction conditions:1.0 mmol aromatic amine,1.5 mmol Michael acceptor,0.3 mmol [DBU][Lac], reaction temperature (25℃), reaction time (05-12 h), product yields (65-95%). Various aromatic amines were subjected to 2-cyclohexen-l-one,2-cyclopenten-l-one and chalcone, and good to excellent yields were obtained. This protocol also has some advantages, such as readily work-up of the reactions and excellent reaction selectivity and good recyclability of the ionic liquid (reused for 8 times without significant loss of activity). The paper also used the ionic liquids as catalysts for Michael reaction with malononitrile, ethyl cyanoacetate, ethyl acetoacetate, methyl acetoacetate, acetylacetone, dimethyl malonate, diethyl malonate, and nitromethane between active methylene compounds and chalcone. [DBU][Ac] is a suitable catalyst with good recyclability. Reaction time is 5-600 min and product yields are between 67-96%.A protocol for Knoevenagel condensation of aromatic aldehydes with methylene compounds catalyzed by task specifed ionic liquid [DBU][Ac] under solvent-free conditions has been developed. The reactions proceed at ambient temperature and the work-up procedures are very simple. The ionic liuid could be simply prepared and recycled efficiently. Reaction time is 1-300 min and product yields are between 65-95 %.The paper also studied the Knoevenagle condensation reactions with water as reaction media. The results show that [DBU][Ac] is suitable catalyst. This protocol has notable advantages, such as high product yields, aqueous reaction medium, ease of work-up, reuse of ionic liquid on large scale for 10 times without the obviously decreace in the condensation yields. Finally. The paper used the weekly acidic ionic liquid [DBU][Tfa] as reaction media for Knoevenagel condensation of aromatic aldehydes and Meldrum' acid. The paper found that the reaction could proceed smoothly without any catalyst. Reaction time is 10-80 min and product yields are between 69-97%. The ionic liquid [DBU][Tfa] remained the dual role of reaction media and efficient catalyst or promoters after reused for 5 times.In summary, the five novel task-specific ionic liquids [DBU][Tfa], [DBU][Ac], [DBU][Lac], [DBU][n-Pr], and [DBU][n-Bu] used as catalysts and/or reaction medium for Michael addition and Knoevenagel condensation have advantages such as short reaction time, high product yields, and good ablity of recyclability for comparison with traditional catalysts or organic solvents.
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