离子液体催化烷基化反应的研究进展

烷基化催化剂发展至今已有多种,如浓硫酸、氢氟酸、杂多酸、分子筛和离子液体等各超强酸类催化剂.用无机酸催化烷基化反应已有较好的技术并被工业化,但存在着许多技术问题,其致命的缺点是存在着严重的设备腐蚀和环境污染等问题.20世纪90年代后期兴起的绿色化学是从源头清除污染     

离子液体超酸清洁催化苯的烷基化反应

研究了在具有Lewis酸性的离子液体体系中进行的苯与烯烃及卤代烃的烷基化反应.以氯化1-甲基-3-乙基咪唑(MEIC)、氯化1-丁基吡啶(BPC)、氯化l-甲基-3-丁基咪唑(MBIC)及盐酸三甲胺(TMHC)季铵盐分别与AlCl3原位合成法制备离子液体催化体系.结果表明:以上各种离子液体均有很高的催化活性,反应转化率在较短的时间内达到100%.其中TMHC-A1Cl3离子液体单烷基化选择性达98.6%.与AlCl3相比,催化活性显著提高,生成烷基化产物不溶于离子液体,因而易于分离,催化剂可重复使用.     

酸性离子液体催化的异丁烷/丁烯烷基化反应研究

以一系列酸性离子液体作为催化剂,考察了异丁烷/丁烯在不同离子液体中催化异丁烷与丁烯的烷基化反应,研究了离子液体在进行酸性和阴阳离子调整后对烷基化反应的影响.其中[MBSIM]OTf类离子液体催化所得目的产物三甲基戊烷含量最高可达69.8%,该类催化体系重复使用8次,催化性能没有明显下降.     

超临界条件下离子液体催化苯与丙烯烷基化的反应机理研究

用FT-IR和¹H NMR分析KOH无水乙醇溶液滴定前后的盐酸三乙胺无水乙醇溶液, 发现(C₂H₅)₃NHCl中的H具有显著的质子酸性, 且在滴定过程中有KCl生成, 滴定后的¹H NMR谱中δ 7.3处的谱峰完全消失. 将合成的(C₂H₅)₃NHCl/AlCl₃离子液体脱水, 在超临界条件下催化全氘代苯与丙烯的烷基化. 用同位素取代法, 研究了反应机理. 结果表明, 脱水后的离子液体仍然可以催化烷基化反应, 液体产物的GC-MS分析结果支持正碳离子机理. 对比反应前后离子液体的¹H NMR谱图发现, 反应后离子液体中盐酸三乙胺中与N相连H的谱峰强度较反应前降低了80.12%, 可能是引发反应消耗了这部分H.     

离子液体催化苯乙烯类化合物的氢烯基化和烷基化反应

Brnsted酸性离子液体作为反应介质和催化剂,实现了苯乙烯类化合物的氢烯基化反应和富电子芳烃参与的氢烷基化反应,取得了优秀的产率和选择性,其产率最高可达到97%,底物适应性比较好,易于放大到克量级,为反式1,3-二芳基1-丁烯化合物和1,1-二芳基乙烷类化合物的制备提供了绿色合成新途径,值得一提的是本方法能以85%的产率高效合成抗蛋白凝聚药物3i,表现出了很好的实用价值.     

改性离子液体中异丁烷与丁烯的烷基化反应

向由无水三氯化铝和盐酸三乙基胺合成的离子液体中溶入不同过渡金属（铜、铁、锌等）离子，考察它们对离子液体催化异丁烷与丁烯烷基化反应性能的影响。结果表明：过渡金属离子的加入能不同程度地影响离子液体的催化性能。溶入Cu2+和Cu+后，离子液体的催化性能有显著的改善，当Cu2+的摩尔加入量为三氯化铝的5%时，烷基化油收率达到丁烯体积的178%，对C8的选择性为75%，烷基化油辛烷值（RON）为92.2，并且离子液体可以重复使用。     

功能化离子液体催化碳-杂键形成反应

离子液体独特的溶剂性能使它在合成和催化领域得到了广泛的应用。然而,离子液体的经济问题和可能的环境友好性问题使得人们逐渐把目光投向了离子液体自身的催化性能。人们通过对离子液体结构的修饰设计出了各种具有特定催化性能的功能化离子液体。近年来功能化离子液体在催化碳-杂键形成反应方面有了相当多的应用。本文以形成的碳-杂原子键类型为主线,综述了功能化离子液体在催化碳-杂键形成反应方面的最新研究进展,涉及到了酸性离子液体、碱性离子液体、金属有机功能化离子液体、酸碱双功能离子液体、手性离子液体等多种类型的功能化离子液体。     

吗啉基功能化酸性离子液体催化苯酚-叔丁醇选择性烷基化反应

研究了吗啉基磺酸功能化离子液体催化苯酚与叔丁醇的烷基化反应.考察不同的功能化离子液体、反应时间、反应温度、苯酚与叔丁醇的摩尔比以及离子液体的用量等反应条件对烷基化反应的影响,并考察了离子液体的循环使用.研究结果表明离子液体用量为20%苯酚时,在最佳优化条件下苯酚的转化率和选择性分别为92.4%和64.1%;离子液体重复使用三次,其催化活性不变.     

离子液体中异丁烷/2-丁烯烷基化反应机理研究

以复合离子液体[Et_3NH]Cl-AlCl_3-CuCl为催化剂,在连续搅拌釜式反应器中进行了异丁烷与2-丁烯烷基化反应;利用氘代异丁烷同位素示踪法研究了催化反应机理。结果表明,在离子液体中异丁烷烷基化的反应诱导期较短;三甲基戊烷产物主要源于异丁烷的自烷基化、丁烷/丁烯的直接烷基化以及C_(12)~+中间体的裂化反应,而大部分二甲基己烷是仲丁基碳正离子与丁烯加成的产物。     

[bmim]Cl/FeCl3离子液体催化苯与乙烯烷基化的反应机理

 利用FT-IR和1H NMR对KOH无水乙醇溶液滴定前后的氯化1-正丁基-3-甲基咪唑(［bmim］Cl)无水乙醇溶液进行分析发现,［bmim］Cl咪唑环上的2-H具有显著的质子酸性,滴定后的NMR谱中化学位移为9.5处的2-H信号完全消失,且在滴定过程中有KCl生成. 通过［bmim］Cl/FeCl3离子液体的1H NMR分析发现,咪唑环上的氢质子尤其是2-H的化学位移与FeCl3含量密切相关,随着FeCl3与［bmim］Cl摩尔比的增大, 2-H的化学位移向低场移动,说明其去屏蔽作用增强, 2-H更容易脱离. 将合成的［bmim］Cl/FeCl3离子液体脱水,并采用同位素置换的方法研究了离子液体催化全氘代苯与乙烯的烷基化反应机理. 结果表明,脱水后的离子液体仍然可以催化烷基化反应. 通过对反应后液体产物的GC-MS分析,提出了离子液体催化的苯与乙烯烷基化反应的正碳离子机理. 反应前后离子液体的1H NMR分析表明,反应后离子液体中咪唑环上的2-H的信号强度较反应前降低了23%,说明引发反应所需要的H+一部分是由咪唑环上的2-H提供的.     

Cu对离子液体异丁烷/丁烯烷基化反应选择性的影响研究

合成并表征了[BMIm]Cl-1.8AlCl3-0.5CuCl、[Et3NH]Cl-1.8AlCl3/CuAlCl4等离子液体,考察了含Cu离子液体等酸性催化剂中的异丁烷/丁烯烷基化反应,研究了Cu对离子液体烷基化选择性的影响。结果表明,Cu的引入对离子液体酸性的影响较小,不是反应选择性提高的主要原因,而烷基化过程中CuAlCl5-/CuAlCl4等配合物的存在,以及它们对2-丁烯的络合吸附是改善离子液体催化选择性的关键因素。相同反应条件下,[Et3NH]Cl-1.8AlCl3/CuAlCl4、[BMIm]Cl-1.8AlCl3/CuAlCl4等催化剂的三甲基戊烷选择性最高可达87.5%(质量分数),产物辛烷值100.5,明显优于硫酸、常规氯铝酸离子液体和复合离子液体等烷基化汽油辛烷值。     

Chlorogallate(III) ionic liquids: Synthesis, acidity determination and their catalytic performances for isobutane alkylation

A series of triethylammonium-based chlorogallate(Ⅲ) ionic liquids with varied Lewis acidity was synthesized, characterized, and firstly applied to isobutane alkylation. The [Et3NHCl]-GaCl3 with χGaCl3 = 0.65 displayed a potential catalytic activity for the alkylation. The addition of copper halide into the chlorogallate(Ⅲ) ionic liquids dramatically enhanced the alkylation reaction. Up to 70.1% C8 selectivity and 91.3 RON were achieved with the [Et3NHCl]-GaCl3-CuCl (χGaCl3 = 0.65, CuCl = 5% mol) under 0.5 MPa, 900 r/min, 15 min, 288 K using the industrial C4 cut (isobutane/butene = 10). These results indicate that the chlorogallate(Ⅲ) system may be used as a promising catalyst for the C4 alkylation.     

吡啶离子液体催化作用下的FCC汽油烷基化脱硫

合成一种Brønsted酸性离子液体[BPY]HSO₄,采用红外光谱和核磁共振对其进行表征。以[BPY]HSO₄为催化剂,对FCC汽油进行烷基化脱硫,考察反应温度、反应时间和剂油质量比对脱硫效果的影响及脱硫前后FCC汽油性质的变化,并对[BPY]HSO₄进行了再生。结果表明,在反应温度为65 ℃、反应时间为90 min和剂油质量比为0.09的条件下,FCC汽油的硫含量从580.0 μg/g降至6.4 μg/g,脱硫率为98.90%,满足中国国Ⅴ车用汽油硫含量标准(<10 μg/g);脱硫前后硫分布变化表明,在[BPY]HSO₄的催化作用下,前170 ℃馏分油中硫化物大部分转移到后170 ℃重馏分中,重馏分中硫化物可采用加氢方法进行脱除;PONA组成变化表明,烷基化脱硫过程对FCC汽油的烃类组成影响较小,且脱硫前后辛烷值变化不大;[BPY]HSO₄经萃取再生后可循环使用。     

Cyclotrimerization of an aliphatic aldehyde catalyzed by acidic ionic liquid

Without any additional organic solvent, the cyclotrimerization of aliphatic aldehyde could be catalyzed by acidic ionic liquid. Under optimum reaction conditions (298 K, 1 h, a molar ratio of 60:1 of isobutyraldehyde to ionic liquid), the conversion rate and selectivity for cyclotrimerization of isobutyraldehyde were 93.0 and 100%, respectively. The liquid product formed a separate phase that was decanted and the solid product could be separated by extraction. The ionic liquid could be easily reused after removal of water under vacuum.     

Coke precursor as an intermediate during the alkylation of isobutane/butene over a solid superacid

Alkylation of isobutane/butene was conducted on a Brønsted-Lewis conjugated solid superacid. It is found that some hydrocarbons accumulated on the catalyst surface. These hydrocarbons, as called coke precursor, played an intermediate role at the initial stage of the alkylation before they lead the catalyst to lose its activity. The presence of the intermediate is beneficial to the alkylation between isobutane and butene, while increase the TMP content and TMP/DMH ratio in the products     

离子液体降低FCC汽油烯烃体积分数的研究

向FCC汽油中分别加入两种与FCC汽油不互溶的Lewis超强酸性离子液体\[Bmim\]Cl-AlCl3 和 \[R4N\]Cl-AlCl3形成液-液两相催化降烯烃体系。结果表明：在汽油辛烷值基本保持不变的基础上,FCC汽油的烯烃体积分数分别下降14.7%和13.1%, 均达到我国新配方汽油规定的烯烃体积分数v<35%的新标准。对离子液体降低FCC汽油的机理及影响因素进行了详细研究。结果表明,正是由于具备Lewis超强酸性的离子液体催化的烯烃与烷烃的烷基化、烯烃与芳烃的烷基化以及烯烃的二聚反应使得FCC汽油中烯烃体积分数显著下降。     

Functional mesoporous poly (ionic liquid) derived from P123: From synthesis to catalysis and alkylation of styrene and o‐xylene

A novel strategy was proposed for the fabrication of high‐performance acidic mesoporous poly ionic liquids catalyst. In this work, mesoporous poly ionic liquids (MPILs) were synthesized with P123 (PEO₂₀PPO₇₀PEO₂₀) served as pore‐forming agent. Then, MPILs were treated with PW^3? anion exchange, thereby fabricating PW/MPIL‐S(x). MPIL and PW/MPIL‐S(x) were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), Thermogravimetric analysis (TA), N₂ adsorption–desorption and Fourier transform infrared (FT‐IR) spectra and X‐ray photoelectron spectroscopy (XPS) spectra. The effect of solvent and concentration of P123 on the morphology and mesoporous structure of MPILs were investigated systematically. And the results show that MPILs were featured with mesoporous channel structure, high surface area (up to 737 m²/g) and large pore volumes (1.16 cm³/g), which benefit heterogeneous phase reaction (such as, alkylation of styrene with o‐xylene). In the alkylation reaction, under optimal reaction conditions, the catalyst PW/MPIL‐THF (4.0 g) shows high conversion of styrene (100%) and PXE yield (96.21%), demonstrating the excellent catalytic activities. Furthermore, PW/MPIL‐S(x) are easy to be separated from the catalytic system by filtration and show no obvious decrease in catalytic activity after 6 cycle runs. The obtained PW/MPIL‐S(x) catalyst exhibit high thermal and mechanical stability as well, indicating extensive application in high temperature acidic catalysis. This work might open up a new method for the synthesizing of porous polymer catalysts in the future.     

Extraction and determination of hormones in cosmetics by homogeneous ionic liquid microextraction high-performance liquid chromatography

The homogeneous ionic liquid microextraction was applied to the extraction of hormones from cosmetics and the hormones were determined by high-performance liquid chromatography. 1-Hexyl-3-methylimidazolium tetrafluoroborate was used as extraction solvent. Ammonium hexafluorophosphate as used as ion-pairing agent. Several experimental parameters, including the volume of 1-hexyl-3-methylimidazolium tetrafluoroborate, amount of ammonium hexafluorophosphate and sodium chloride, extraction and centrifuge time, and the pH value, were optimized. The limits of detection and quantification for the analytes ranged from 0.03 to 0.24 ng/mL and from 0.10 to 0.79 ng/mL, respectively. The precision for determining the hormones was lower than 5.2%. The proposed method was successfully developed for the determination of hormones in real cosmetic samples.     

新型碱性离子液体催化酯交换合成生物柴油

两步法合成了吗啉阴离子型碱性离子液体1-丁基-3-甲基吗啉盐Im,经 ¹H-NMR和FT-IR分析确认了离子液体中间体的结构,并通过阴离子交换得到碱性离子液体,对该离子液体在酯交换制备生物柴油反应中的催化性能进行了研究。结果表明,该碱性离子液体Im具有较高的酯交换催化活性,在60 ℃、催化剂用量为3%、醇油物质的量比为6.5：1.0、反应2 h的条件下,产物脂肪酸甲酯（FAME）含量可达95.80%。而且该离子液体的催化稳定性较好,重复使用5次后仍有较高的催化活性。