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1.
离子液体因其所独有的物理化学性质如蒸气压低、热稳定性好以及结构和性能的可调性等优点而备受关注.四羰基钴阴离子是多种重要均相催化反应的催化活性物种,含有四羰基钴阴离子的金属有机离子液体有效结合了羰基金属和离子液体各自的特点和优势,作为一类新颖而且重要的功能化离子液体,受到国内外研究者的青睐.2001年,Dyson等首次报道了一种室温下为液态的羰基钴金属有机离子液体[bmim][Co(CO)_4],为四羰基钴阴离子离子液体的研究开创了先河.此后,有关羰基钴金属有机离子液体的催化应用研究也相继报道.目前[CnPy][Co(CO)_4]以及[bmim][Co(CO)_4]在环氧化合物的羰基化反应中已有报道,但该类催化剂的催化活性特别是循环使用性能有待进一步提高.胍盐具有阳离子电荷分散程度高、热稳定性和化学稳定性高、三个氮原子上的基团可以调节等特点,使得胍盐离子液体的设计、合成和应用研究受到国内外学者关注.由于其自身结构特点,氮原子上有取代氢可以和含F,O,N底物作用形成氢键,并且氮原子上取代烷基之间作用使阳离子的平面结构发生变化,使得与三个氮原子相连的碳原子处于缺电子状态,使阳离子表现出Lewis酸性.所以其在环氧化合物氢酯基化反应中可起到稳定四羰基钴阴离子以及活化环氧化合物的作用.基于此,本文以较高收率合成了四种新型的1,1,3,3-四烷基胍羰基钴金属有机离子液体:1,1-二甲基-3,3-二乙基胍羰基钴(3a),1,1-二甲基-3,3-二正丁基胍羰基钴(3b),1,1-二甲基-3,3-四亚甲基胍羰基钴(3c),1,1-二甲基-3,3-五亚甲基胍羰基钴(3d).通过红外光谱、紫外-可见光谱、1H核磁共振谱、13C核磁共振谱、高分辨质谱、差示量热扫描仪和热重分析对该类化合物进行了结构确认及性质研究.这四种催化剂,特别是3a,在环氧化合物的氢酯基化反应中表现出优异的催化性能,在无需任何助剂的情况下具有较好的催化活性及底物适用性.此外,以不同构型的环氧丙烷为反应底物,氢酯基化反应结果显示:在该催化体系作用下,产物的构型与底物保持一致,没有发生消旋.尤其值得指出的是,催化剂3a在环氧丙烷的氢酯基化反应中表现出了优异的循环稳定性能,在循环使用6次后依然可以获得较好的转化率(91%)和选择性(94%).  相似文献   

2.
陈静  傅宏祥等 《分子催化》2001,15(2):146-148
在用于羰基合成的钴催化剂中加入适当的配合物或离子 ,可以提高其稳定性并改善反应产物的正 /异比 . Mastuda等人 [1,2 ] 首次用吡啶修饰的羰基钴催化剂体系催化丙烯和丁二烯的羰化酯基化反应 ,并提出可以用喹啉代替吡啶 . 1 980年 ,Kojima等人[3 ] 在较温和的反应条件下 ,将几种含烯醇结构的含氮杂环化合物用于乙烯的氢甲酰化反应中 ,得到了较好的结果 .同时 ,Schaefer[4 ]以辛烯为底物 ,较为详细地研究了钴 /吡啶催化剂体系对烯烃氢酯基化反应的作用 ,以及不同吡啶 /钴摩尔比对产物分布的影响 .在此期间 ,除了对吡啶作配体的钴催化剂有…  相似文献   

3.
室温离子液体中二氧化碳与环氧化合物的电催化插入反应   总被引:6,自引:0,他引:6  
杨宏洲  顾彦龙  邓友全 《有机化学》2002,22(12):995-998
在温和条件下,二氧化碳在室温离子液体中可以被电化学活化。同时,活化后 的二氧化碳在室温离子液体中与环氧化合物发生插入反应生成环状碳酸酯也得到了 较好的结果。[BMIm][BF4]离子液体为反应介质,环氧丙烷为反应底物时得到最佳 反应结果。电化学活化对反应的发生是必需的。  相似文献   

4.
运用核磁共振手段, 研究了室温离子液体1-辛基-3-甲基咪唑四氟硼酸盐([C8mim][BF4])在不同比例的离子液体/丙酮混合体系中1H和13C的化学位移及13C的自旋-晶格弛豫时间(T1). 结果表明, 离子液体[C8mim][BF4]的阳离子芳环上的氢原子, 以及与氮原子直接相连的甲基和亚甲基上的氢原子都与丙酮羰基上的氧原子有相互作用, 从而减弱了离子液体阴阳离子间的强相互作用, 使离子液体的运动加快, 黏度降低.  相似文献   

5.
改进了1-丁基-3-甲基咪唑L-脯氨酸([bmim][Pro])功能化离子液体的合成路线,并将该离子液体用于催化含活泼亚甲基化合物与醛或酮的Knoevenagel缩合反应.在水介质中,室温下,该离子液体可快速催化上述Knoevenagel缩合反应,并选择性生成α,β-不饱和羰基化合物且分离收率可达到88%~97%.该脯氨酸离子液体循环重复使用6次后,催化活性没有明显的下降.此外,初步探讨了其催化过程机理.  相似文献   

6.
采用原位法合成了不同类型的四羰基钴/咪唑离子液体催化剂, 并考察了其在氯乙酸甲酯羰基化反应中的催化性能. 研究了咪唑环上不同支链对催化活性的影响. 结果表明, 1-丁基-3-甲基咪唑羰基钴离子液体[Bmim][Co(Co)4]不仅催化活性高, 选择性好, 而且对空气和水有较好的稳定性能. 在pCO=2.0 MPa, 85 ℃, 反应3 h的条件下, [Bmim][Co(Co)4]催化剂循环使用4次, 氯乙酸甲酯的平均转化率为94.3%, 丙二酸二甲酯的平均选择性和平均产率分别为98.5%和92.9%. 与传统的Na[Co(Co)4]催化剂相比, [Bmim][Co(Co)4]催化剂在保证高活性的条件下可以实现羰基钴催化剂的直接循环使用.  相似文献   

7.
杨秉勤  白银娟  高波  张秉林 《化学学报》2010,68(16):1629-1634
以二茂铁为原料, 通过合成1,1'-二乙酰基二茂铁、1,1'-二茂铁二甲酸、1,1'-二茂铁二甲酰氯, 在高度稀释条件下与4种二羟乙基苯胺进行酯化反应得到了1,9-二羰基-2,8-二氧-5-(4-氟)苯基氮[9]二茂铁酯环蕃a, 1,9-二羰基-2,8-二氧-5-(4-甲基)苯基氮[9]二茂铁酯环蕃b, 1,9-二羰基-2,8-二氧-5-(4-甲氧基)苯基氮[9]二茂铁酯环蕃c, 1,9-二羰基-2,8-二氧-5-(4-硝基)苯基氮[9]二茂铁酯环蕃d. 用UV、1H NMR、FT-IR、元素分析和基质辅助激光解析电离-飞行时间质谱(MALDI-TOF)对这些化合物进行了表征. 培养了二茂铁酯环蕃a的单晶, 并对其结构进行了解析.  相似文献   

8.
魏荣宝  李洪波  梁娅 《化学学报》2007,65(19):2151-2154
以1,4-环己二酮、丙二酸二乙酯及多元醇等为原料, 经过两次“一锅煮”法合成了六种二代螺环树形化合物1,2,3,4,5,6,7,8,9,10,11,12-十二氢-2,2;6,6;10,10-三[3,3-二(烷氧羰基)-1,1-环亚丁基二甲氧基]三亚苯基螺环树形化合物, 其中烷氧基为异戊氧基、三羟甲基甲氧基、2,2-二溴甲基-3-羟丙氧基、2,2-二羟甲基丙氧基、二羟甲基膦甲氧基和(N-羟甲基-N-二羟甲基氨基乙基)甲氧基. 利用IR, NMR, MS和元素分析对合成的化合物进行了结构认证, 对影响反应的因素进行了讨论.  相似文献   

9.
配体1,1-双(四甲基环戊二烯基)二茂铁1,1-Fc(Me4Cp)2(Ⅰ)与五羰基铁在二甲苯中回流反应, 得二茂铁桥连双(四甲基环戊二烯基)四羰基二铁1,1-Fc[(Me4Cp)Fe(CO)(μ-CO)]2(1). 化合物1在氯仿中与单质碘反应, Fe_Fe键断裂, 生成二茂铁桥连双铁碘化合物1,1-Fc[(Me4Cp)Fe(CO)2I]2(2). 配体Ⅰ与正丁基锂作用生成二茂铁桥连双(四甲基环戊二烯基负离子盐), 后者随即与三乙腈三羰基钼反应形成1,1-二茂铁双(四甲基环戊二烯基负离子盐)1,1-Fc[(Me4Cp)Mo(CO)3-Li+]2(Ⅱ). 钼负离子Ⅱ与CH3I作用在钼原子上发生甲基化, 得到产物1,1-Fc[(Me4Cp)Mo(CO)3Me]2(3). Ⅱ与BrCH2CH2Br反应, 未得到预期的Mo_Mo键化合物, 相反却得到少量亲核取代-消除的双钼-溴化合物1,1-Fc[(Me4Cp)Mo(CO)3Br]2(4). 经元素分析、 IR及1H NMR表征化合物1-4的结构, 并用X射线衍射测定了化合物1的晶体结构.  相似文献   

10.
Brφnsted酸性离子液体催化合成长链脂肪酸甲酯   总被引:2,自引:0,他引:2  
本文合成了以1-丁基-3-甲基咪唑为阳离子,HSO4-、H2PO4-和BF4-为阴离子的Brφnsted酸性离子液体,并以长链脂肪酸与甲醇的酯化反应考察了这些Brφnsted酸性离子液体的催化性能。实验结果表明,1-丁基-3-甲基咪唑硫酸氢根鎓盐([bmim][HSO4])离子液体具有很高的催化活性,当n(醇)∶n(酸)∶n(离子液体)=6∶1∶0.25,反应温度为70℃,不分水酯化反应2h,长链脂肪酸甲酯的产率可达到93.4%以上,选择性达到100%;且产物酯与离子液体分离容易;离子液体经干燥处理后可以循环使用5次以上,催化活性没有明显降低。  相似文献   

11.
Through an optimized synthetic strategy, a series of novel alkylpyridinium cobalt tetracarbonyl salts, [C(1)Py][Co(CO)(4)] (), [C(4)Py][Co(CO)(4)] () and [C(16)Py][Co(CO)(4)] () (C(n)Py = N-C(n)H(2n+1)-pyridinium), were successfully prepared in good yields, using a water-organic biphasic system. All the three compounds melt well below 100 degrees C and could be classified as ionic liquids. The compounds were fully characterized using IR, UV-Vis, (1)H NMR, (13)C NMR, ESI-MS and elemental analysis, and was structurally characterized by X-ray single crystal analysis. Compound has been found to be an efficient and reusable catalyst for the alkoxycarbonylation of propylene oxide without the aid of a base additive.  相似文献   

12.
In this work, 3,3′-(((1E,1′E)-(H,12H-5,11-methanodibenzo[b,f][1,5]diazocine-2,8-diyl)bis(ethene-2,1-diyl))bis(1,1-dimethyl-1H-benzo[e]indole-3-ium-2,3-diyl))bis(propane-1-sulfonate) (1), 3,3’-(((1E,1′E)-(6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine-2,8-diyl)bis(ethene-2,1-diyl))bis(3,3-dimethyl-3H-indole-1-ium-2,1-diyl))bis(propane-1-sulfonate) (2), 2,2’-((1E,1′E)-(6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine-2,8-diyl)bis(ethene-2,1-diyl))bis(1,3,3-trimethyl-3H-indol-1-ium) iodide (3) and 2,2’-((1E,1′E)-(6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine-2,8-diyl)bis(ethene-2,1-diyl))bis(1,1,3-trimethyl-1H-benzo[e]indol-3-ium) iodide (4) were designed and synthesized by ethylene bridging of the N-substituted indolium salts and the Tröger’s Base (TB) framework. The probes exhibited a longer absorption and emission wavelength and the emission wavelength of them in dichloromethane (DCM) was more than 600 nm, performed a red fluorescence. All of the probes could work on the extreme acidic and the extreme alkaline environments and showed a good liner response in the working pH range. Especially, 2 and 4 were soluble in water and manifested a good pH sensing in a water system. Also, 1H NMR analysis illustrated how these dyes worked as the pH-sensitive fluorescence probes. In addition, they performed excellent reversibility, high selectivity and good photostability.  相似文献   

13.
In this paper, synthesis of 1,3-propanediol (1,3-PDO) through coupling of hydroesterification-hydrogenation from ethylene oxide (EO) catalyzed by 1-butyl-3-methylimidazolium cobalt tetracarbonyl [Bmim][Co(CO)4] functional ionic liquid which was prepared by metathesis reaction between [Bmim]Cl and KCo(CO)4 has been studied. The structure of [Bmim][Co(CO)4] was characterized by FT-IR and 1H NMR. Using [Bmim][Co(CO)4] as catalyst and [Bmim]PF6 as solvent, 1,3-PDO was prepared for the first time by coupling of hydroesterifaction of EO and hydrogenation of methyl 3-hydroxypropionate (3-HPM). The yield of 3-HPM can reach 90.8%, while the yield of 1,3-PDO up to 82.9%. The catalyst can be separated from the product mixture by extraction with deionized water and recycled several times without significant loss of catalytic efficiency. A possible reaction mechanism has also been proposed.  相似文献   

14.
The development of a highly active and selective porphyrin-based epoxide carbonylation catalyst, [(OEP)Cr(THF)2][Co(CO)4] (1; OEP = octaethylporphyrinato; THF = tetrahydrofuran), is detailed. Complex 1 is a separated ion pair composed of a tetracarbonylcobaltate anion and an octahedral chromium porphyrin complex axially ligated by two THF ligands. Regarding the carbonylation of epoxides to beta-lactones, catalyst 1 exhibits excellent turnover numbers (up to 10,000) and turnover frequencies (up to 1670 h(-1)), with regioselective carbonyl insertion occurring between the oxygen and the sterically less hindered carbon of the epoxide substrate. Complex 1 is highly tolerant of nonprotic functional groups, carbonylating an array of aliphatic and cycloaliphatic epoxides, as well as epoxides with pendant ethers, esters, and amides. With careful control of reaction conditions in the carbonylation of glycidyl esters, the exclusive production of either the beta- or gamma-lactone isomer was achieved. Through analysis of reaction stereochemistry, a mechanism for the formation of gamma-lactone products was proposed. Overall, a broad array of synthetically useful lactones has been synthesized in a rapid and selective fashion by catalytic carbonylation using [(OEP)Cr(THF)2][Co(CO)4].  相似文献   

15.
A new highly active and selective catalyst for the synthesis of beta-lactones from CO and epoxides is reported. The catalyst, [(N,N'-bis(3,5-di-tert-butylsalicylidene) phenylenediamino)Al(THF)2][Co(CO)4] ([(salph)Al(THF)2][Co(CO)4]) is easily prepared from the corresponding (salph)AlCl and NaCo(CO)4. At 50 degrees C and 880 psi of CO, the catalyst (1 mol %) carbonylates epoxides such as propylene oxide, 1-butene oxide, epichlorohydrin, and isobutylene oxide to the lactones beta-butyrolactone, beta-valerolactone, gamma-chloro-beta-butyrolactone, and beta-methyl-beta-butyrolactone in high yield. (R)-Propylene oxide was carbonylated to (R)-beta-butyrolactone with retention of stereochemistry.  相似文献   

16.
Organozinc compounds prepared from dialkyl dibromomalonates and zinc react with 2-arylmethyl-eneindan-4,6-diones, 5-arylmethylene-2,2-dimethyl-1,3-dioxane-4,6-diones, as well as with 2-[4-(1,3-dioxoindan-2-ylidenemethyl)phenyl]methyleneindan-1,3-dione and 5-[4-(2,2-dimethyl-4,6-dioxo-1,3-dioxane-2-ylidenemethyl)phenyl]methylene-2,2-dimethyl-1,3-dioxane-4,6-diones to form dialkyl 3-aryl-1′3′-dioxaspiro(cyclopropane-2,2′-indan)-1,1-dicarboxylates, dimethyl 3-aryl-6,6-dimethyl-5,7-dioxa-4,8-dioxaspiro[2,5]octan-2,2-dicarboxylates, dialkyl 2-{4-[3,3-bis (alkoxycarbonyl)-1′,3′-dioxaspiro(cyclopropane-2,2′-indan)-1-yl]phenyl}-1′,3′-dioxaspiro[cyclopropane-2,2′-indan]-1,1-dicarboxylates, and dialkyl 2-{4-[2,2-bis(alkoxycarbonyl)-6,6′-dimethyl-4,8-dioxo-5,7-dioxaspiro[2,5]oct-1-yl]phenyl}-6,6-dimethyl-4,8-dioxo-5,7-dioxaspiro[2,5]octan-1,1-dicarboxylate respectively.  相似文献   

17.
The microwave reactions of InX3 with [Q]Y produce a series of tetrahaloindate(III)-based ionic liquids (ILs) with a general formula of [Q][InX3Y] (Q = imidazolium, phosphonium, ammonium, and pyridinium; X = Cl, Br, I; Y = Cl, Br). The reaction of CO2 with a variety of epoxides has been examined in the presence of these ILs wherein tetrahaloindate(III)-based ILs are found to exhibit high catalytic activities and evidence is presented that supports the significant role of H-bonding interactions in the [Q][InX3Y]-catalyzed coupling reactions. The effects of various parameters such as temperature, pressure, and molar ratio of propylene oxide to catalyst have been investigated, and the plausible reaction mechanism based on the 1H and 13C NMR studies is presented for the formation of propylene carbonate.  相似文献   

18.
以L-色氨酸为原料合成了5个伯酰胺结构的轴手性双咔啉N—O催化剂N2,N2'-二氧-9,9'-二甲基-3,3'-取代甲酰胺-β-双咔啉(4A~4E),并用于不对称催化酮亚胺的还原反应.结果表明,催化剂的催化转化率较高(80%~98%),立体选择性(e.e.值)较好,其中催化剂N2,N2'-二氧-9,9'-二甲基-3,3'-环己基甲酰胺-β-双咔啉(4B)的催化转化率达到了98%,e.e.值达68%.  相似文献   

19.
In this paper, functional ionic liquid 1-butyl-3-methylimidazolium cobalt tetracarbonyl [Bmim][Co(CO)4] is prepared in a metathesis reaction between [Bmim]Cl and KCo(CO)4. The structure of [Bmim]+ is illustrated by 1H NMR, while [Co(CO)4] is confirmed by IR(νCO) spectrum. Methyl 3-hydroxypropionate(3-HPM), an intermediate to 1,3-propanediol (1,3-PDO), can be prepared in high yield by hydroesterification of ethylene oxide in the presence of a [Bmim][Co(CO)4] catalyst. Under a pressure of 3.7 MPa and at a temperature of 75 °C, the yield of 3-HPM can reach 90.8% in 10 h. Even after the catalyst is recycled three times, a yield of more than 80% can be obtained. A possible reaction mechanism has also been proposed.  相似文献   

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