过渡金属卟啉／高价盐体系催化分子氧对芳烃侧链氧化的研究

研究了四-全氟苯基卟啉过渡金属(TPFPPM,M=Co、Mn、Fe)/高价金属盐体系催化分子氧对烷基芳烃侧链氧化反应.结果表明,TPFPPCo催化乙苯及其衍生物的侧链氧化时,加入底物1/800的K2Cr2O7对反应有很好的促进作用,乙苯最高转化率达55.2%,苯乙酮收率为51.0%.该催化体系对于取代烷基苯,如正丙苯、正丁苯和对-溴乙苯也具有很好的催化效果.     

NHPI/Co(Salen)催化氧化取代甲苯

以分子氧为氧化剂,N-羟基邻苯二甲酰亚胺(NHPI)为引发剂,Co(Salen)配合物[NHPI/Co(Salen)]为催化剂,偶氮二异丁腈(AIBN)为助引发剂,AcOH为溶剂,催化氧化取代甲苯制备取代苯甲酸。最佳反应条件为:甲苯6mmol,q(NHPI)=10%,q[Co(Salen)]=0.5%,q(AIBN)=1%,O2(0.1MPa),AcOH10mL,于80℃反应20h,甲苯转化率92.7%,苯甲酸选择性88.9%。     

离子液体体系中离子型锰卟啉对苯乙烯的催化氧化

以单氧给体乙酰碘苯[PhI(OAc)2]为氧源, 在无需轴向配体和有机溶剂的参与下, 离子型锰卟啉[MnⅢ(BF4)T(N-Me-4-Py)P][BF4]4和离子液体 [BMIM]BF4组成的多元离子液体体系, 在温和的反应条件下对苯乙烯的催化氧化表现出较高的活性(87%)和环氧苯乙烷选择性(90％), 并且有较好的底物普适性. 构筑的锰卟啉多元离子液体体系可以一定程度上抑制卟啉聚合和氧化降解等反应.     

四羰基钴/咪唑离子液体在羰基化合成丙二酸二甲酯反应中的催化性能

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p_CO=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.     

聚合物微球固载的N-羟基邻苯二甲酰亚胺在分子氧氧化甲苯过程中的催化性能

以交联聚苯乙烯(CPS)微球为基质,经过几步大分子反应在微球表面合成与固载了N-羟基邻苯二甲酰亚胺(NHPI),形成固载有NHPI的聚合物微球CPS-NHPI。本文主要将CPS-NHPI与过渡金属盐组成共催化体系,用于分子氧氧化甲苯的反应,考察了该非均相催化剂的催化特性与催化氧化机理。结果表明,几种过渡金属盐中,Co(OAc)2的助催化效果最好;微球CPS-NHPI与Co(OAc)2所构成的共催化体系,在温和条件(80℃和常压氧气)下可有效地将甲苯深度氧化为苯甲酸,显现出高的催化活性(甲苯转化率达到57%)与优良的选择性(苯甲酸的选择性达到84%)。催化氧化反应遵循自由基链式反应机理。主催化剂CPS-NHPI固载的NHPI与助催化剂Co(OAc)2适宜的摩尔比为14∶1,主催化剂所含NHPI为底物的12(mol)%时,催化剂用量较为合适。固体催化剂CPS-NHPI具有良好的再循环使用性能。     

新型钨酸盐的合成及催化环氧化环戊烯反应

合成了新型喹啉十聚钨酸盐化合物[C3Quin]4W10O32,并对该化合物催化环氧化环戊烯的反应进行研究.考察了催化剂([C3Quin]4W10O32),氧化剂(UHP),反应溶剂([Bmim]BF4)和反应时间等因素对反应收率的影响,优化出最佳反应条件:在反应温度35℃,环戊烯1mmol,催化剂15μmol,氧化剂2.5mmol,离子液体0.4mL,反应时间8h,环氧环戊烷产率达到99%.     

不同阴离子组成的离子液体对产紫青霉生长、代谢及催化特性的影响

研究了6种不同阴离子分别与1-丁基-3-甲基咪唑阳离子[Bmim]+组成的6种离子液体对产紫青霉(Penicillium purpurogenum Li-3)细胞生长、代谢、细胞膜透性和催化活性的影响.结果表明,[Bmim]Ac和[Bmim]Tf2N对菌体细胞的生长和代谢具有明显的抑制作用;6种离子液体均改善了细胞膜透性,其中以[Bmim]Ac最明显;全细胞催化反应实验表明,在分别含25%的疏水性离子液体[Bmim]PF6和[Bmim]Tf2N的2种介质体系中,甘草酸(GL)生物转化合成单葡萄糖醛酸基甘草次酸(GAMG)的转化率分别为82.73%和89.84%,GAMG的产率分别为68.65%和76.23%,与不含离子液体的纯缓冲溶液体系相比(GL转化率和GAMG产率分别为81.82%和33.31%),GL的转化率均略有提高,而GAMG的产率则提高了2倍多,表明2种疏水性离子液体对全细胞催化反应的定向性具有明显促进作用;亲水性离子液体[Bmim]Ac,[Bmim]Cl和[Bmim]NO3对细胞的催化活性具有明显的抑制作用,而[Bmim]BF4的抑制作用则较弱.     

离子液体中酮肟O-烷基化反应的研究

以[Bmim]PF6,[Bmim]BF4,[Bmim]OH为介质,以NaOH为缚酸剂,由酮肟与卤烷、硫酸酯等烷基化剂在20～40℃反应1～2h,以52%～94%的收率制备了酮肟醚衍生物,产物结构经1HNMR,GC-MS表征.结果表明,该方法简便易操作,所用离子液体对环境友好,并可循环使用.     

新型离子液体介质中长链烯烃氢甲酰化反应

合成和表征了离子液体[Rmim][p-CH3C6H4SO3](R=CH3(CH2)n—, n=3, 7, 11, 15), 并以所合成的离子液体为反应介质, 考察了水溶性铑膦络合物HRh(CO)(TPPTS)3[TPPTS: P(m-C6H4SO3Na)3]对长链烯烃氢甲酰化反应的催化性能. 结果表明, 离子液体[Rmim][p-CH3C6H4SO3]中R基团链长的变化对催化活性具有重要的影响；而在相同离子液体中, 氢甲酰化反应活性随着烯烃链长的增加明显下降. 与文献报道中广泛使用的离子液体[Bmim]BF4、[Bmim]PF6相比, 该催化体系对长链烯烃氢甲酰化反应具有更好的活性和化学选择性, 在3.0 MPa, 100 ℃的条件下, 1-己烯氢甲酰化反应转化频率(TOF)高达2736 h-1. 反应完成后, 水溶性铑膦络合物能很好地溶解在离子液体中, 与有机物自动分层, 催化剂的循环使用易于实现.     

先锋褐煤在离子液体1-丁基-3-甲基咪唑三氟甲磺酸盐作用下热溶解聚及其产物分析

考察了先锋褐煤(XL)在高温稳定性很好的离子液体1-丁基-3-甲基咪唑三氟甲磺酸盐([Bmim]OTf)中的解聚性能,并对其在不同热溶条件下解聚所得热溶物和残煤进行了分析表征。结果表明,[Bmim]OTf对XL具有较好的解聚性能。在280℃,[Bmim]OTf/XL为3.5下解聚4h,[Bmim]OTf对XL的萃取率(以四氢呋喃可溶物计)为20.1%。四氢萘(THN)、H₂和催化剂ZnCl₂的加入可显著促进XL在[Bmim]OTf中的解聚,相比于XL在[Bmim]OTf作用下的萃取率,THN、H₂和催化剂ZnCl₂的加入使可溶物的收率分别提高到30.0%、36.9%和46.8%。产物分析结果表明,在[Bmim]OTf热溶解聚XL的过程中THN的加入使得XL经离子液体[Bmim]OTf解聚所得热溶物中氢键的数量明显增加;H₂和ZnCl₂的添加分别增加了产物中脂肪烃和芳烃的含量。     

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。     

Alkane Oxidation with Molecular Oxygen Using a New Efficient Catalytic System: N-Hydroxyphthalimide (NHPI) Combined with Co(acac)(n)() (n = 2 or 3)

A novel class of catalysts for alkane oxidation with molecular oxygen was examined. N-Hydroxyphthalimide (NHPI) combined with Co(acac)(n)() (n = 2 or 3) was found to be an efficient catalytic system for the aerobic oxidation of cycloalkanes and alkylbenzenes under mild conditions. Cycloalkanes were successfully oxidized with molecular oxygen in the presence of a catalytic amount of NHPI and Co(acac)(2) in acetic acid at 100 degrees C to give the corresponding cycloalkanones and dicarboxylic acids. Alkylbenzenes were also oxidized with dioxygen using this catalytic system. For example, toluene was converted into benzoic acid in excellent yield under these conditions. Ethyl- and butylbenzenes were selectively oxidized at their alpha-positions to form the corresponding ketones, acetophenone, and 1-phenyl-1-butanone, respectively, in good yields. A key intermediate in this oxidation is believed to be the phthalimide N-oxyl radical generated from NHPI and molecular oxygen using a Co(II) species. The isotope effect (k(H)/k(D)) in the oxidation of ethylbenzene and ethylbenzene-d(10) with dioxygen using NHPI/Co(acac)(2) was 3.8.     

A new strategy for alkane oxidation with O2 using N‐hydroxyphthalimide (NHPI) as a radical catalyst

A practical catalytic method to convert alkanes into the corresponding oxygen‐containing compounds with O₂ under mild conditions using N‐hydroxyphthalimide (NHPI) in the presence or absence of a transition metal was developed. Thus, cyclohexane was successfully converted into adipic acid in good conversion and selectivity by a combined catalytic system consisting of NHPI and Mn(acac)₂. Lower alkane such as isobutane was converted into t‐butyl alcohol (83%) under 10 atm of air by NHPI‐Co(OAc)₂ system. Alkylbenzene such as toluene was oxidized to benzoic acid in high yield (81%) under normal temperature and pressure of dioxygen in the presence of a catalytic amount of NHPI and Co(OAc)₂. ESR measurements showed that phthalimide‐N‐oxyl generated from NHPI under dioxygen atmosphere is a key species in this oxidation and functions as a radical catalyst.     

甲苯氧化制苯甲酸的新催化体系

以分子氧为氧化剂,探索了甲苯氧化制苯甲酸的新催化体系,第一次把N-羟基邻苯二甲酰亚胺(NHPI)与钴盐组成的催化剂用于甲苯氧化反应.实验揭示:以NHPI/Co(acac)2(乙酰丙酮酸钴)和NHPI/Co(OAc)2(醋酸钴)为催化剂时,苯甲酸的收率可分别为55.5%与41.2%,文中还对氧气压力、反应温度与时间等对反应的影响进行了讨论,同时提出了可能的反应机理.     

Significantly Enhanced Reactivities of the Nucleophilic Substitution Reactions Induced by Microwaves in Ionic Liquid

The reaction rate of nucleophilic substitution can be dramatically enhanced by microwave irradiation using the ionic liquid [Bmim]BF4 as a solvent. Nucleophilic reagents (anilines, thiophenol) react with ethoxymethylene isopropylidene malonate to give corresponding products in 5–10 min in good yields.     

Doebner condensation in ionic liquids [Bmim]BF_4 and [Bpy]BF_4 to synthesize α,β-unsaturated carboxylic acid

Ionic liquids[Bmim]BF_4 and[Bpy]BF_4 were employed as environmentally benign media in Doebner condensation to synthesizeαβ-unsaturated carboxylic acid.The good results showed that[Bmim]BF_4 and[Bpy]BF_4 were efficient media for Doebner condensation,which could be recycled easily.The highest yields could reach 93%and 90%in[Bmim]BF_4 and[Bpy]BF_4,respectively.     

Ionic liquid-promoted ring-closure reactions between 1,4-dihydroxyanthraquinone and diamines

The reaction of 1,4-Dihydroxyanthraquinone with diamines was carried out in the presence of CuCl(2), CuCl in the ionic liquid [Bmim]PF(6), [Bmim]BF(4) or [Bmim]Cl x CuCl.     

Efficient oxidation of alcohols to carbonyl compounds with molecular oxygen catalyzed by N-hydroxyphthalimide combined with a Co species

Highly efficient catalytic oxidation of alcohols with molecular oxygen by N-hydroxyphthalimide (NHPI) combined with a Co species was developed. The oxidation of 2-octanol in the presence of catalytic amounts of NHPI and Co(OAc)2 under atmospheric dioxygen in AcOEt at 70 degrees C gave 2-octanone in 93% yield. The oxidation was significantly enhanced by adding a small amount of benzoic acid to proceed smoothly even at room temperature. Primary alcohols were oxidized by NHPI in the absence of any metal catalyst to form the corresponding carboxylic acids in good yields. In the oxidation of terminal vic-diols such as 1,2-butanediol, carbon-carbon bond cleavage was induced to give one carbon less carboxylic acids such as propionic acid, while internal vic-diols were selectively oxidized to 1,2-diketones.     

Homocoupling of Aryl Iodides Catalyzed by Cyclopalladated Complexes of Tertiary Arylamines

Homocoupling of aryl iodides catalyzed by cyclopalladated complexes of tertiary arylamines gives symmetric biaryls with good yields in DMA or ionic liquid [Bmim]BF4. This catalytic alternative of the Ullmann reaction has proved to be sensitive to both electronic and steric factors of substrates.     

吡咯烷酮酸性离子液体中硼酸酯的催化合成

研究了硼酸与频哪醇和环己醇在离子液体1-甲基-2-吡咯烷酮硫酸氢盐（[Hnmp]HSO4）、1-丁基-3-甲基咪唑四氟硼酸盐（[Bmim]BF4）及1-丁基-3-甲基咪唑六氟磷酸盐([Bmim]PF6)中生成2-环己氧基-4,4,5,5-四甲基-1,3,2-二氧硼烷的酯化反应。 考察了不同离子液体、反应温度、反应时间和离子液体与反应物物质的量比等对反应的影响。 结果表明,当n(硼酸)∶n(频哪醇)∶n(环己醇)∶n([Hnmp]HSO4)=1∶1∶1∶1,反应温度为70 ℃和反应时间为4 h时,硼酸酯的产率为72.5%,离子液体重复使用4次,催化活性无明显降低。