An efficient method to synthesize TNAD by the nitration of 1,4,5,8- tetraazabicyclo-[4,4,0]-decane with N20s and acidic ionic liquids

An experimental study was carried out on the direct nitration of 1,4,5,8-tetraaza-bicyclo-[4,4,0]-decane to synthesize 1,4,5,8-tetranitro-1,4,5,8-tetraazabicyclo-[4,4,0]-decane(TNAD) with N2O5 catalyzed by acidic ionic liquids. Various ionic liquids, such as [HMim]X, [(CH2)4SO3HMim]X and [Capl]X(X = pTSO, NO3, HSO4), and various parameters such as equivalents of ionic liquid, molar ratio of N2O5 to the starting material, reaction time and temperature, and solvent were investigated. Ionic liquid [(CH2)4SO3HMim]HSO4 showed better catalytic activity. In the presence of 3% molar ratio of [(CH2)4SO3HMim]HSO4 ionic liquid to the staring material, the yield of 1,4,5,8-tetranitro-1,4,5,8-tetraazabicyclo-[4,4,0]-decane was improved by 6.2% compared to the system without ionic liquid.     

离子液体中卤素交换氟化合成七氟醚

在离子液体作为反应介质的条件下,以六氟异丙基氯甲基醚的氟代反应合成了七氟醚。 探讨了氟代反应机理,考察了[bpy]BF4、[bmim]BF4、[bepy]BF4、[bmim]PF6对反应产率的影响,研究了氟化剂、水和温度对反应产率的影响。 结果表明,以[bepy]BF4为反应介质,高比表面积的KF和微量的水有利于固态KF的部分离解进入有机相形成高活性的F-从而减少副产物,收率达到94.6%。 离子液体可重复使用3次以上,其活性没有明显下降。     

呋喃类化合物在离子液体和硅胶负载离子液体中的Diels-Alder反应研

以1-丁基3-甲基咪唑盐作为离子液体阳离子,与三种不同阴离子BF4、PF6、Tf2N组成性质不同的三种离子液体,催化呋喃类和丁炔二羧酸酯之间发生的Diels-Alder反应,合成了一系列化合物,研究了离子液体的催化效果。研究表明,呋喃类化合物的极性越低, Diels-Alder 反应的活性越高。在含硫的呋喃类化合物的反应中,当以 [Bmim]PF6 作为离子液体时,Diels-Alder 反应的产率可达到53%。另外,当 [Bmim]PF6 离子液体被吸附在硅胶表面上时,Diels-Alder的反应产率有所提高。     

DABCO离子液体催化Knoevenagel缩合反应

以三乙烯二胺(DABCO)为原料,通过两步法制备了离子液体[DABCO-PDO][PF6];将其用于催化芳香醛与多种活性亚甲基化合物(丙二腈,氰基乙酸乙酯,苯并噻唑乙腈,苯乙腈)的Knoevenagel缩合反应;讨论了可能的反应机理,并基于催化剂的双重催化作用阐述了反应的高效性.结果表明,该反应体系无需任何溶剂,在室温(25℃)下就能进行,催化剂用量小,反应时间短,收率高,反应后处理简单,反应普适性较高;且催化剂重复使用5次后仍保持很高的催化活性.     

Direct analysis of catalysts immobilised in ionic liquids using electrospray ionisation ion trap mass spectrometry

Catalysts immobilised in ionic liquids have been analysed using electrospray ionisation ion trap mass spectrometry, which allows identification of the catalyst without contamination from the ionic liquid; additionally, a new ionic liquid containing the Monsanto catalyst as the anionic component, [Rh(CO)2I2]-, has been characterised using the same method.     

[4+2] Annulation of 3-(2,2-diethoxyethyl)-1,3-dicarbonyl compounds with indoles catalyzed by Brønsted acid ionic liquid for the synthesis of carbazoles

Various carbazoles were synthesized via [4+2] annulation of 3-(2,2-diethoxyethyl)-1,3-dicarbonyl compounds with indoles. A Brønsted acid ionic liquid, [BPy]HSO₄, was proven to be effective catalyst for this reaction. The ionic liquid catalyst can be recycled three times without significant loss of its catalytic activity.     

Br(o)nsted酸性离子液体在醛醇缩合反应中的应用

合成了一系列Br(o)nsted酸性离子液体并将其应用在醛醇缩合反应中.醛醇缩合产物由于极好的溶剂性质等被广泛用作溶剂和试剂.离子液体[BSmim][OTf]在甲醛和乙二醇缩合生成1,3-二氧五环的反应中表现出了极好的催化活性,甲醛转化率和主产物1,3-二氧五环选择性分别可以达到96.1％和92.4％.对影响离子液体催化性能的因素进行了探索,并对催化反应中的离子液体的用量、反应温度、反应时间以及反应物料比进行了考察.通过Hammett酸度函数法测定了所用到离子液体的酸性,结果表明离子液体酸性与其在缩合反应中的催化活性顺序完全一致,酸性越强催化性能越好.结合实验给出了离子液体[BSmim][OTf]催化甲醛和乙二醇缩合反应的可能的反应机理.该催化剂体系具有良好的催化性能,反应可以在较温和的条件下进行,实现了高活性和高选择性的目标,产物易分离,催化剂重复使用7次,其催化活性基本不变.并将该Br(o)nsted酸性离子液体进一步应用到其他醛(酮)醇缩合反应中.     

功能离子液体复合体系中钯催化的Heck偶联反应

在[BMIM][TPPMS]离子型膦配体和碱性离子液体 [BMIM][OAc] 组成的功能离子液体复合体系中, PdCl2(CH3CN)2可以有效地催化溴苯和丙烯酸乙酯的交叉偶联(Heck)反应, 产物肉桂酸乙酯(反式)的收率达到60%. 锚定在功能离子液体复合体系中的Pd催化剂循环使用11次后仍保持良好的活性和稳定性. 该催化剂体系的良好活性和稳定性可归因于三个方面: [BMIM][TPPMS]和[BMIM][OAc]间的协同配位效应; 以[BMIM][OAc]作为Heck反应的缚酸剂, 避免了无机盐粘稠物的形成; 生成的副产物[BMIM]Br可以有效溶解钯黑, 避免了钯黑的析出. 该离子液体催化体系对不同底物的Heck偶联反应也表现出良好的普适性.     

Mono- and multi-layer adsorption of an ionic liquid on Au(110)

Ultraviolet photoelectron spectroscopy (UPS), work function measurements, low energy electron diffraction (LEED) and scanning tunnelling microscopy (STM) have been used to study the adsorption and desorption of 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide, [C(2)C(1)Im][Tf(2)N], on the (1×2) clean surface reconstruction of Au(110) in the temperature range 100-674 K. The ionic liquid adsorbed without decomposition, and desorbed without leaving any residue on the surface. For adsorption at room temperature a monolayer of strongly bound ionic liquid was formed with four interface states visible in UP spectra. STM at 100 K showed that the monolayer consisted of well-ordered rows of adsorbed ionic liquid aligned parallel to the close packed rows of surface gold atoms (the [110] direction) with a separation of ×2 (the same as the clean surface reconstruction) between the rows in the orthogonal [001] direction. Multilayer adsorption at room temperature occurred by droplet formation followed by smoothing of the droplets to a layered morphology with time. Heating caused multilayer desorption at temperatures in the 363-383 K range, followed by partial monolayer desorption at 548 K to produce a Au(110)-(1×3) reconstructed surface with sub-monolayer domains of ionic liquid. Desorption of the remaining ionic liquid at 600 K caused the gold surface to reconstruct back to the clean (1×2) reconstruction.     

Room Temperature Ionic Liquid： a Powerful Additive of Mn（Salen） Catalyzed Oxidation of sec-Alcohols

A simple, mild, efficient Mn(salen)-catalyzed oxidation system of secondary alcohols, in which the ionic liquid [bmim]PF6 acts as a powerful additive, has been described. The reaction proceeded with higher efficiency. The catalyst was more easier to recycle in ionic liquid [bmim]PF6 with a well-proportioned CH2Cl2 than in the single CH2Cl2 or ionic liquid.     

Masked mercapto acid-driven MCR in task-specific ionic liquid: a new sterocontrolled entry into bicyclic 1,3-thiazines

An unprecedented multi-component reaction for the synthesis of thiosugar-annulated 1,3-thiazines is reported. The envisaged synthetic strategy involves the reaction of d-glucose/d-xylose and 2-methyl-2-phenyl-1,3-oxathiolan-5-one with AcONH₄/RNH₂ in task specific ionic liquid (TSIL), [bmim]SCN which afforded thiosugar annulated 1,3-thiazines in excellent yields (83–93%). The reaction is effected via ionic liquid promoted Michael addition followed by mercaptoacetylative ring transformation in a one-pot procedure and the ionic liquid, [bmim]OH could be easily recycled for further use without any loss of efficiency and be used for the synthesis of [bmim]SCN, thus allowing recycling of the TSIL for further use.     

Brønsted酸性离子液体在醛醇缩合反应中的应用

合成了一系列Brønsted酸性离子液体并将其应用在醛醇缩合反应中.醛醇缩合产物由于极好的溶剂性质等被广泛用作溶剂和试剂.离子液体[BSmim][OTf]在甲醛和乙二醇缩合生成1,3-二氧五环的反应中表现出了极好的催化活性,甲醛转化率和主产物1,3-二氧五环选择性分别可以达到96.1%和92.4%.对影响离子液体催化性能的因素进行了探索,并对催化反应中的离子液体的用量、反应温度、反应时间以及反应物料比进行了考察.通过Hammett酸度函数法测定了所用到离子液体的酸性,结果表明离子液体酸性与其在缩合反应中的催化活性顺序完全一致,酸性越强催化性能越好.结合实验给出了离子液体[BSmim][OTf]催化甲醛和乙二醇缩合反应的可能的反应机理.该催化剂体系具有良好的催化性能,反应可以在较温和的条件下进行,实现了高活性和高选择性的目标,产物易分离,催化剂重复使用7次,其催化活性基本不变.并将该Brønsted酸性离子液体进一步应用到其他醛（酮）醇缩合反应中.     

Uranium halide complexes in ionic liquids: an electrochemical and structural study

The electrochemistry of the salts, [emim]2[UBr6] and [emim]2[UO2Br4] ([emim] = 1-ethyl-3-methylimidazolium), has been investigated in both a basic and an acidic bromoaluminate(III) ionic liquid. In the basic ionic liquid, the hexabromo salt undergoes a one-electron reversible reduction process at a stationary glassy carbon disc electrode, while the tetrabromodioxo salt was reduced to a uranium(IV) species by an irreversible two-electron process with the simultaneous transfer of oxide to the ionic liquid. On the other hand, dissolution of either of the salts in an acidic bromoaluminate(III) ionic liquid resulted in the formation of the same electroactive species. The solid state structures of the uranium chloride salts, [emim]2[UCl6] and [emim]2[UO2Cl4], have previously been reported, but have now been re-evaluated using a new statistical model developed in our group, to determine the presence or absence of weak hydrogen bonding interactions in the crystalline state.     

Efficient and Green Protocol for the Synthesis of thioamides in C6(mim)2Cl2 as a dicationic ionic liquid

A simple, efficient, facile and eco-friendly process for the synthesis of thioamides from nitriles using 1,6-bis(3- methylimidazolium-1-yl)hexane chloride [C₆(mim)₂Cl₂] as a dicationic ionic liquid (DIL) was developed. The ionic liquid was easily separated from the reaction mixture and was recycled at least four times without any loss of its activity.     

无溶剂条件下新型功能离子液体催化活性亚甲基化合物与查尔酮的Michael加成研究

以基于DBU(1,8-diazabicyclo[5.4.0]undec-7-ene)的新型功能离子液体[DBU][Ac],[DBU][Lac],[DBU][Tfa],[DBU][n-Pr]和[DBU][n-Bu]为催化剂,研究了无溶剂条件下活性亚甲基化合物与查尔酮的Michael加成反应.反应时间短、收率高、后处理简单、离子液体重复使用6次而活性未发现明显下降.     

Preparation of fructone catalyzed by water-soluble Brφnsted acid ionic liquids

Fructone(2-methyl-2-ethylacetoacetate-1,3-dioxolane),a flavouring material,has been synthesized from ethyl acetoacetate and glycol using five water-soluble Br(?)nsted acid ionic liquids as catalysts for the first time.The used Br(?)nsted acid ionic liquids include [Hmim]Tfa,[Hmim]Tsa,[Hmim]BF_4,[Bmim]HSO4,[Bmim]H_2PO_4,and[Hmim]BF_4 showed the highest catalytic activity for the preparation of fructone.After reaction,the product could be isolated from the reaction system automatically,and the ionic liquid could be directly reused without dehydration.     

离子液体介质中一锅法合成2-氨基-4-苯基-6-(苯基硫基)-3,5-二氰基吡啶衍生物

考察了各种不同介质中,芳醛、丙二腈和苯硫酚为原料的一锅反应,发现在离子液体1-正丁基-3-甲基咪唑四氟硼酸盐([bmim]BF4)介质中,反应能够在较短时间内高产率地生成2-氨基-4-苯基-6-(苯基硫基)-3,5-二氰基吡啶衍生物,且没有1,4-二氢吡啶副产物的生成.该方法具有反应条件温和、产率高、选择性好和环境友好等优点,且离子液体容易回收,可循环使用.     

室温离子液体中水溶性铑膦配合物催化1-己烯氢甲酰化反应的研究

研究了水溶性膦配体铑配合物在若干离子液体中的1-己烯氢甲酰化反应性能．通过改变离子液体的阴阳离子结构，可使水溶性TPPTS-铑配合物在离子液体中表现出较高的卜己烯氢甲酰化反应活性和选择性；在[BMI]BF4离子液体中加入适量的水，可提高TPPTS-铑配合物的催化活性；在[BMI]BF4离子液体中，水／有机两亲性膦配体与铑形成的配合物，反应后催化剂与产物自动分层，实现催化剂的循环使用．本文结果表明，水溶性膦配体铑配合物的催化活性与其在离子液体中的溶解度密切相关．     

Brønsted acidic ionic liquids promoted cyclocondensation reaction: Synthesis of 1,8-dioxo-octahydroxanthene

A new functionalized basic ionic liquid, 4-amino-1-(2,3-dihydroxy propyl) pyridinium hydroxide [ADPPY] [OH], has been introduced as a catalyst for the synthesis of tetrahydrobenzo[b]pyrans under mild conditions. The desired products can be separated directly from the reaction mixture with high purity. Only 10 mol% catalyst was needed with a sequestration time of 10 min. In addition, the ionic liquid used can be regenerated and recycled several times without significant loss of activity.     

[Omim][NO3], a Green and Base-Free Medium for One-Pot Synthesis of Benzothiazinones at Room Temperature

A general and efficient room-temperature procedure is developed for high-yield synthesis of 2H-benzo[b][1,4]thiazin-3(4H)-one derivatives in one pot from the reaction of 2-aminothiophenols with 2-bromoalkanoates in ionic liquid [bmim]NO₃ without the use of any catalyst, base, or additive. Products were obtained in good yields by simple extraction with Et₂O followed by evaporation of the volatile contents and recrystallization from Et₂O. The ionic liquid was recycled and reused in the next reaction without the loss of its activity.