十八醇亲核取代反应修饰溴代多壁碳纳米管

Octadecanol modified multiple-walled carbon nanotubes, with octadecanol covalently bound to the nanotube surface, have been synthesized by bromination of the carbon nanotubes followed by nucleophilic substitution using octadecanol and sodium hydride. Scanning electron microscopy and transmission electron microscopy images show that the morphologies of the nanotubes are largely intact after functionalization. The brominated carbon nanotubes and octadecanol modified carbon nanotubes were characterized using energy-dispersive X-ray spectroscopy, Raman spectroscopy and Fourier transform infrared spectroscopy. The mechanism of nucleophilic substitution was discussed, and it is believed that the reaction occurs with an SN1 mechanism.     

过渡金属配合物催化氯代芳烃亲核取代反应的新进展

苯、萘以及各种芳香杂环的多官能化衍生物是聚合物、药物、香料、染料、炸药、杀虫剂等的重要中间体 ,从相应的卤代芳烃出发合成这些化合物是经济和合理的 .但由于卤代芳烃对亲核取代的不活泼性 ,使这一设想受到很大的限制 .近年来 ,金属有机化学的发展 ,给卤代芳烃的化学带来了勃勃生机 .以过渡金属催化碘代或溴代芳烃与各种亲核试剂反应 ,作为形成碳 -碳键、碳 -杂原子键的有效手段 ,已进行了广泛而深入的研究 .而对相应的氯代芳烃的研究起步较晚 ,这主要是受 C- Cl键强度的影响 (如氯苯的键能为 40 2 k J/mol;而溴苯、碘苯分别为 339.4…     

孕甾三醇的区域选择性乙酰化/溴代反应的研究

为合理利用剑麻皂甙元资源, 系统地考察了孕甾-3S,16S,20S-三醇和溴化氢/乙酸溶液的反应, 并且发现了孕 甾-3S,16S,20S-三醇的区域选择性乙酰化溴代反应, 从而为转化孕甾-3S,16S,20S-三醇成为16R-溴代孕甾-3S,20S-二醇二乙酸酯提供了一个有效方法.     

溴氯混合卤代羟基二苯醚抑菌剂的合成

氯代羟基二苯醚以其优越的杀菌能力,广谱性和低毒性广泛应用于化妆品,洗涤剂,医药,医疗器械等领域。     

取代1-吲酮的α-溴代反应

从取代3-苯丙酸出发,在多聚磷酸中直接环合(或先生成酰氯,再以三氯化铝催化环合)得到12个取代1-吲酮(Ⅰa~Ⅰl)。Ⅰ10 mmol溶于40 mL混合溶剂[V(乙酸乙酯)∶V(氯仿)=1∶1]中,搅拌下回流,分3批加入溴化铜(60%,24%和16%),经α-溴代反应得取代2-溴-1-吲酮(Ⅱa~Ⅱl,其中Ⅱf,Ⅱj,Ⅱk和Ⅱl未见文献报道),收率67.2%~91.5%。新化合物的结构经1H NMR确证。     

H_3PO_4/Zr(OH)_4高效促进NBS对取代烷基苯的亲电溴代

使用固体酸H3PO4/Zr(OH)4催化NBS对取代烷基苯进行苯环溴代反应.根据不同取代烷基苯的反应活性,在乙腈中,高产率(79%～96%)地得到了相应的苯环单溴代产物,同时反应体系中无苄位溴代的副产物生成.在反应过程中,固体酸催化剂可以重复使用多次.     

溴代作用对竹红菌素分子性质影响的理论研究

用AM1方法对红菌素（包插甲素和乙素）与它们的溴代物进行了量子化学对比计算,得到了生成热,前线轨道能级及偶极矩等,讨论了溴代作用对竹红菌素分子性质的影响。     

TEBABr_3对苯胺类的溴代反应

作者在三乙基苄基氯化铵和溴酸钠的水溶液中加入氢溴酸,以高产率制得 PhCH_2Et_3N~+·Br_3~-(TEBABr_3,1)。1为橙色固体,m.p.73～74℃,能在 CH_3OH-CH_2Cl_2介质中于 NaH-     

溴代作用对竹红菌乙素分子性质影响的量子化学研究

用半经验量子化学方法AM1和PM3对竹红菌乙素及其溴代物进行了对比计算,考察了溴代作用对竹红菌乙素分子性质的影响。两种方法所得结果均表明,溴代作用使分子的生成热、前线轨道能级及偶极矩等参数都有所降低,溴代作用也影响了竹红菌乙素分子内氢键的性质,并能使其对光的吸收产生红移。     

1-溴乙酰基薁-3-甲酸甲酯在离子液体中的亲核取代反应

在室温离子液体[Bm im BF4]中,亲核试剂与1-溴乙酰基薁-3-甲酸甲酯进行取代反应,高选择性、高收率地生成1-取代乙酰基薁类衍生物,其结构经1H NMR,IR和元素分析确认。     

还原温度对超细K－Co－Mo催化剂合成低碳醇性能的影响

 用溶胶－凝胶法合成了K－Co－Mo催化剂．样品经不同温度还原后，用于低碳醇的合成．XRD和HRTEM结果表明，样品是超细粒子，粒子尺寸为2～5nm．考察了催化剂的还原温度和反应条件对催化剂性能的影响．实验结果表明，还原温度对催化剂的活性有较大的影响，最佳还原温度为500℃．最佳反应温度范围为310～330℃．升高压力和空速可以提高醇的收率和选择性．在空速14400h－1，压力6．0MPa和温度310℃的条件下，醇的选择性为55．8％，收率为520．0g／（kg·h），MeOH／C2＋OH为0．27．催化剂稳定性良好，在200h的寿命实验中，活性基本不变．与文献中催化剂相比，超细K－Co－Mo催化剂对合成醇具有较高的活性和选择性，尤其是对C2＋OH的合成明显高于其他合成醇催化剂体系．     

Reaction of Nucleophilic Polyhalogenalkylation in Two and Three-Component Systems

Abstract

The halophilic reactions of the derivatives of P^III R₃ P (R = R2N, Alk, Ar) with CCl₄, having preparative signifi-cance, are studied thoroughly. As far as the compounds of R₂PHlg type are concerned, at the beginning of our re-searches there was was an opinion that the interaction of R₂PHlg with CC14 cannot be possible because of the low nucleophility of phosphorus. We determined for the first time that diamidochlorophosphites 1 react with CC14 at the temperature 20°C and form the compounds 2, 3.¹      

Synthesis,Structure, and Photophysical Properties of Yellow-Green and Blue Photoluminescent Dinuclear and Octanuclear Copper(I) Iodide Complexes with a Disilanylene-Bridged Bispyridine Ligand

The synthesis, structural, and photophysical investigations of CuI complexes with a disilanylene-bridged bispyridine ligand 1 are herein presented. Dinuclear (2) and ladder-like (3) octanuclear copper(I) complexes were straightforwardly prepared by exactly controlling the ratio of CuI/ligand 1. Single-crystal X-ray analysis confirmed that dinuclear complex 2 had no apparent π…π stacking whereas octanuclear complex 3 had π…π stacking in the crystal packing. In the solid state, the complexes display yellow-green (λ_em = 519 nm, Φ = 0.60, τ = 11 µs, 2) and blue (λ_em = 478 nm, Φ = 0.04, τ = 2.6 µs, 3) phosphorescence, respectively. The density functional theory calculations validate the differences in their optical properties. The difference in the luminescence efficiency between 2 and 3 is attributed to the presence of π…π stacking and the different luminescence processes.     

3,5-二烷基-1,2,4-三唑衍生物构筑的两个Cu4I4簇配合物的合成、结构和荧光性质

以3,5-二甲（丙）基-4-氨基-1,2,4-三唑为配体,与CuI在H₂O/MeCN混合溶剂热合成了2个构型不同的Cu₄I₄超分子化合物{[Cu₂（aadmtrz）I₂]·CH₃CN}_n （1）和[Cu₂（dptrz）I]_n （2）（aadmtrz=4-（（1-氨乙基）-氨基）-3,5-二甲基-1,2,4-三唑,dptrz=3,5-二丙基-1,2,4-三唑）,并进行了元素分析,红外,X射线粉末衍射及单晶衍射等表征。2个配合物中Cu₄I₄构型不同,配合物1中,Cu₄I₄簇连结成一个8环椅式-椅式结构,通过配体连接成（4,4）二维菱形格子结构;而配合物2中,Cu₄I₄簇呈畸变的立方烷结构,构成了含有19.5%孔隙率三维孔洞聚合物,其结构可简化为（3,4）-连接的拓朴结构。同时,在常温下研究了2个配合物的固体荧光性质。     

脱水催化剂的改性对浆态床一步法合成二甲醚的影响

 以Cu(NO3)2为前驱体,以水、丙酮或乙二醇为溶剂,以γ-Al2O3为载体,采用等体积浸渍法制备了用于合成气一步法制二甲醚的脱水-变换双功能催化剂,并对其还原性能、晶态分布、还原态的酸性及催化性能进行了研究. H2-TPR结果表明,以乙二醇为溶剂制备的催化剂上可还原氧化铜的量最多. XRD结果表明,以水为溶剂制备的催化剂上,氧化铜并未完全均匀地分散在氧化铝表面,而是有一部分以单质铜或铜铝化合物的形式存在; 而以丙酮或乙二醇为溶剂制备催化剂时,氧化铜分布均匀. 还原态催化剂NH3-TPD结果表明,以乙二醇为溶剂制备的催化剂上,酸性中心主要集中在弱酸位上. 浆态床搅拌釜中合成反应的结果表明,用氧化铜对脱水催化剂进行改性,能改善催化剂的催化性能,提高CO转化率和产物中二甲醚的选择性,抑制副反应的发生. 非水溶剂的使用对CO转化率没有明显的影响,但可改变催化剂上酸中心的分布,提高二甲醚的选择性,并抑制副反应的发生.     

固相混合氧化物催化剂用于温和条件下醇液相氧化的研究

在氧化反应的研究过程中, 利用清洁的氧化剂, 借助于可循环使用的固相材料为催化剂, 使用对环境友好的溶剂体系, 是绿色氧化反应的一个研究方向. 本工作以混合氧化物Ru-Mn-Fe-Cu-O为催化剂, 分子氧为氧化剂, 甲苯为溶剂, 各类醇均可在温和的条件下迅速地转化成相应的羰基化合物. 发现在有表面活性剂存在情况下, 以水为溶剂该催化剂也可将各类醇实现有效氧化转化, 阳离子表面活性剂比其他类型表面活性剂更可促进催化剂-水-表面活性剂所组成的催化氧化性能.     

CuI/PPh3‐catalyzed Sonogashira coupling reaction of aryl iodides with terminal alkynes in water in the absence of palladium

The Sonogashira cross‐coupling of aryl iodides with terminal alkynes catalyzed by a simple and inexpensive catalyst system of CuI/PPh₃ in water as the sole solvent has been reported. In the presence of CuI/PPh₃, with KOH used as a base, a number of aryl iodides were treated with alkynes to afford the corresponding products in moderate to excellent yields. Copyright © 2008 John Wiley & Sons, Ltd.     

Computational Study of Benzosultam Formation through Gold(I)-Catalyzed Ammoniumation/Nucleophilic Substitution Reaction

The Au(I)-catalyzed reactions of (2-alkynyl)phenylsulfonyl azetidines bearing terminal and non-terminal alkynes in the presence of methanol as protic nucleophile to form benzosultams derivatives were studied by density functional theory (DFT) calculations. Our study highlights that gold(I) catalyzed nucleophilic addition of the nitrogen on the alkyne is favored over the direct ring opening of the azetidine by methanol, confirming the ammonium-based mechanism. In addition, the reverse regioselectivity observed experimentally where non-terminal alkynes favors the formation of 6-endo-dig-benzosultams while terminal alkynes favor 5-exo-dig products is also explored through two different scenarios. The first one embraces the classical activation of the alkyne by a single Au(I) species while the second one tackles the formation of a σ,π-digold acetylide complex. Calculations identify both pathways as competitive although only mono Au(I) complexes can lead to final products, in good agreement with experimental observation. Further details on the importance of the presence of an excess of the protic nucleophile on the protodemetallation step and the final aminal formation is also discussed.     

Copper (I) Iodide-Catalyzed Solvent-Free Synthesis of α-Aminophosphonates

Abstract

A method for the synthesis of α-aminophosphonates through the three-component coupling reaction of aldehydes, amines, and diisopropyl phosphite using copper (I) iodide salt catalyst is demonstrated, The reaction is highly efficient, economic, and also environment friendly.

[Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Table S1, Figures S1–S9.]

GRAPHICAL ABSTRACT      

Alkali Cation Ligating Chains and Sheets of the Macrocycle 1, 7‐Dithia‐18‐Crown‐6 with Bridging Iodo‐ and Thiocyanatocuprate(I) Units

Treatment of an acetonitrile solution of CuI with 1, 7‐dithia‐18‐crown‐6 (1, 7‐DT18C6) at 100°C affords the coordination polymer ¹[(CuI)₂(1, 7‐DT18C6)₂] ( 1 ) in which 1, 7‐DT18C6 ligands bridge (CuI)₂ rings into double chains. 1D polymers of the type ¹[M{(Cu₃I₄)(1, 7‐DT18C6)}] (M = K, 2 ; M = Cs, 3 ) can be isolated under similar conditions in the presence of respectively KI and CsI. Both contain bridging heptacyclic [Cu₆I₈]^2— units but crystallise in different space groups, namely P1 and C2/m. The cesium cation of 3 is markedly displaced from the best plane through the thiacrown ether donor atoms. Reaction of 1, 7‐DT18C6 with CuSCN in the presence of NaSCN yields ²[{Na(CH₃CN)₂} {(CuSCN)₂(1, 7‐DT18C6)}][Cu(SCN)₂] ( 4 ), in which ¹[(CuSCN)₂] double chains are linked through macrocycles into sheets. Infinite ¹[{Cu(SCN)₂}^—] chains compensate the charge of the Na⁺ cations. Complex 1 can imbibe 0.90 mol CsNO₃ per mol of 1, 7‐DT18C6 pairs.