壳寡糖铕、铽配合物的合成、表征及抗·O-2活性

用壳寡糖分别与硝酸铕和硝酸铽反应, 制备了壳寡糖-铕、壳寡糖-铽两种配合物. 用红外光谱、紫外光谱、 荧光和X射线光电子能谱(XPS)等分析测试手段对配合物进行了表征. 以吩嗪硫酸甲酯(PMS)-还原型辅酶Ⅰ烟酰胺腺嘌呤二核苷酸(NADH)-硝基四氮唑蓝(NBT)产生超氧阴离子自由基(·O-2)来研究壳寡糖和壳寡糖稀土金属配合物对·O-2自由基的清除作用. 结果表明: 壳寡糖与Eu3 或Tb3 形成了配合物, 壳寡糖-铕、壳寡糖-铽配合物中不仅壳寡糖氨基上的N原子参与了配位, 同时仲羟基的O原子也参与了配位. 壳寡糖和壳寡糖稀土金属配合物对·O-2均具有明显的清除作用, 配合物与壳寡糖相比对·O-2具有更高的清除活性.     

离子液体型表面活性剂研究

以1-甲基咪唑为原料, 制备了6个常规离子液体: 1-正丁基-3-甲基咪唑四氟硼酸盐及六氟磷酸盐(简称[bmim][BF₄]及[bmim][PF₆])、1-正己基-3-甲基咪唑四氟硼酸盐及六氟磷酸盐(简称[hmim][BF₄]及[hmim][PF₆])、1-正十六烷基-3-甲基咪唑四氟硼酸盐及六氟磷酸盐(简称[C₁₆mim][BF₄]及[C₁₆mim][PF₆])和4个功能化离子液体: 1-(2-羟乙基)-3-甲基咪唑四氟硼酸盐及六氟磷酸盐(简称[2-hemim][BF₄]及[2-hemim][PF₆])、1-乙氧羰基甲基-3-甲基咪唑四氟硼酸盐及六氟磷酸盐(简称[eocmmim][BF₄]及[eocmmim][PF₆]). 研究了这两类离子液体的一些物理性能, 旨在挖掘离子液体在香料香精化妆品工业中的应用价值. 分别检测了它们与一般溶剂的互溶性, 并测定了它们的表面张力和发泡性能, 实验结果表明, 仅[C₁₆mim][BF₄]和[C₁₆mim][PF₆]具有发泡性能, 发泡力分别为68和120 mm.     

离子液体1-乙基-3-甲基咪唑三氟甲基磺酸盐与水之间的氢键作用(英文)

通过衰减全反射红外(ATR-IR)光谱、二维红外相关谱结合量子化学计算研究了1-乙基-3-甲基咪唑三氟甲基磺酸盐([emim][OTf])和水之间的氢键作用.结果表明,在[emim][OTf]-水体系中,当水的浓度较低时(0.1x(D2O)0.3),水分子的主要存在形式是包裹在离子液体中的没有缔合的单体.水分子优先填充到[emim][OTf]的空隙中,并且与[emim][OTf]的阴离子形成"[OTf]-…HOH…[OTf]-"结构,水分子与[emim][OTf]的阳离子的相互作用位点是烷基氢而不是芳香氢;当水分子浓度较高时,水分子倾向于自身缔合形成小团簇结构,水分子与[emim][OTf]的阳离子的相互作用位点是芳香氢而不是烷基氢.     

离子液体/乙烯-醋酸乙烯共聚物复合材料的制备与性能

分别将离子液体三正丁基甲铵(双三氟甲磺酰)亚胺盐([TBMA][NTf₂])和1-乙基-3-甲基咪唑四氟硼酸盐([EMIM][BF₄])与乙烯-醋酸乙烯共聚物弹性体(EVM)熔融共混制备复合材料,研究了离子液体与EVM的相容性及抗静电性能。 样品宏观透明性和SEM测试结果显示,[TBMA][NTf₂]与EVM具有较好的相容性,相应的EVM/[TBMA][NTf₂]复合材料的抗静电效果更好;热重分析(TGA)结果表明,[TBMA][NTf₂]促进EVM热解,而[EMIM][BF₄]对EVM的热稳定影响较小。 室温下在EVM中填加[TBMA][NTf₂]的共混物表现出较好的柔性,当[TBMA][NTf₂]质量分数为20%时,EVM/[TBMA][NTf₂]复合材料的模量为0.58 MPa,断裂伸长率可达到2997%。     

一维[Pd(mnt)2]-自旋体系磁交换作用的密度泛函理论(DFT)分析

4个一维磁链化合物[R-BzPy][Pd(mnt)2](R-BzPy+=对位取代苄基吡啶阳离子;R=Cl(化合物1),Br(化合物2),I(化合物3)和NO2(化合物4))具有相似的晶体堆积结构,即,[Pd(mnt)2]-和R-BzPy+分别形成完全分列的柱状堆积。这一结构特征与其类似化合物[R-BzPy][Ni(mnt)2]相似。但是,[Pd(mnt)2]-和[Ni(mnt)2]-2个系列化合物结构之间存在明显差异:(1)室温下,[R-BzPy][Ni(mnt)2]晶体中[Ni(mnt)2]-和R-BzPy+堆积柱是均匀的;而[R-BzPy][Pd(mnt)2]晶体中[Pd(mnt)2]-和R-BzPy+堆积柱是不均匀的。(2)在两个系列化合物阴离子堆积柱内,相邻[Pd(mnt)2]-分子平面之间距离比相邻[Ni(mnt)2]-分子平面之间距离短。在[Pd(mnt)2]-堆积柱内,[Pd(mnt)2]-离子之间反铁磁交换作用非常强,导致了化合物几乎呈抗磁性。在密度泛函理论框架下,利用对称性破损方法,我们计算了[Pd(mnt)2]-离子之间磁交换常数。在svwn/lanl2dz和bpw91/lanl2dz水平上的计算结果与磁化率拟合结果一致。理论分析揭示,在[Pd(mnt)2]-堆积柱内,[Pd(mnt)2]-离子之间强反铁磁交换与其π-型前线轨道有效重叠密切相关。     

含1H-苯并[d]咪唑或1H-苯并[d][1,2,3]三唑结构的新型查尔酮衍生物的合成及PTP1B抑制活性研究

蛋白酪氨酸磷酸酶1B(PTP1B)作为胰岛素和瘦素信号转导通路的负调节因子,PTP1B抑制剂有希望成为治疗II型糖尿病和肥胖症的候选药物.为了寻找非酸类PTP1B抑制剂,设计、合成了一系列含1H-苯并[d]咪唑或1H-苯并[d][1,2,3]三唑的查尔酮类化合物,并对化合物进行了PTP1B抑制活性测定.结果显示,所有化合物对PTP1B均显示出较强的抑制活性,其中2-(1H-苯并[d][1,2,3]三唑-1-基)-N'-(4-(3-(2'-萘基)-3-氧亚基-丙-1-烯基)苯亚甲基)乙酰肼(10i)活性最佳,IC_(50)为(2.98±0.04)μmol·L~(-1).更重要的是,2-(1H-苯并[d][1,2,3]三唑-1-基)-N'-(4-(3-(4-甲基苯基)-3-氧亚基-丙-1-烯基)苯亚甲基)乙酰肼(10h)在20μg/m L的浓度下对T细胞蛋白酪氨酸磷酸酶(TCPTP)没有活性,显示了较好的选择性.     

新型2-取代苯基-1H-咪唑[4,5-f][1,10]邻菲啰啉基Ru(II)配合物的光电性质

为获取具有活性官能团的接枝型、高性能荧光传感配合物,合成了2-(4-氨基苯基)-1H-咪唑[4,5-f][1,10]邻菲啰啉(CImPB-NH2)、2-(4-羟基苯基)-1H-咪唑[4,5-f][1,10]邻菲啰啉(CImPB-OH)、2-(4-羧基苯基)-1H-咪唑[4,5-f][1,10]邻菲啰啉(CImPB-COOH)和2-(4-硝基苯基)-1H-咪唑[4,5-f][1,10]邻菲啰啉(CImPB-NO2)四种配体,借助紫外-可见(UV-Vis)吸收光谱、荧光(PL)光谱、循环伏安法(CV)和含时密度泛函理论(TD-DFT)对上述四种配体与过渡金属元素钌(Ru)所形成的配合物的光电性能进行研究.结果表明:四种配合物均在可见光区域有较强吸收,发光范围覆盖绿色到红色光波段.在极性溶剂N,N-二甲基甲酰胺(DMF)中,以2-(4-氨基苯基)-1H-咪唑[4,5-f][1,10]邻菲啰啉为配体所构建的钌配合物([Ru(CImPB-NH2)(bpy)2]2+的荧光量子产率(Φ)较不含咪唑环的5-氨基邻菲啰啉合钌([Ru(phen-NH2)(bpy)2]2+)的提高了67%,以2-(4-羧基苯基)-1H-咪唑[4,5-f][1,10]邻菲啰啉所构建的钌配合物([Ru(CImPB-COOH)(bpy)2]2+)的Φ可达29.8%,是[Ru(phen-NH2)(bpy)2]2+的18倍.理论计算表明:配体中取代苯环、咪唑环和邻菲啰啉的稠环共平面,形成共价大π体系,其有效共轭长度较邻菲啰啉母体有显著增加,配合物是以Ru为中心的近似八面体构型,理论计算的电子吸收光谱和跃迁性质与实验结果相一致.上述研究有可能为接枝型、高性能荧光传感配合物的设计和筛选提供实验依据.     

1-乙胺基-3-甲基咪唑四氟硼酸盐吸收CO_2的理论研究

采用密度泛函理论(DFT)对离子液体1-乙胺基-3-甲基咪唑四氟硼酸盐([NH2e-mim][BF4])吸收CO_2的反应机理进行了研究.在B3LYP/6-311++G(d,p)计算水平下,对离子液体[NH2e-mim][BF4]的结构及与CO_2反应的中间体、过渡态和产物进行了全优化,获得了优化结构的构型参数、振动频率和热力学数据.利用自然键轨道(NBO)分析了离子液体[NH2e-mim][BF4]和CO_2的自然电荷布居.计算结果表明,通过阳离子[NH2e-mim]+自偶解离产生的阳离子[NH3e-mim]2+能与阴离子[BF4]-结合形成更强的离子键.根据反应吉布斯自由能变(ΔG0—)和焓变(ΔH0—)的计算结果,判断离子液体[NH2e-mim][BF4]吸收CO_2按理论摩尔比2∶1分步进行反应,吸收过程中质子的转移需克服52.51 k J/mol的能垒.     

具有生物活性的金属配合物的研究 VI: 3,6-二(二甲氨基)-二苯并碘六环镧反式-1,2-环己烷二胺四乙酸配合物的合成, 性质及抗肿瘤活性

本文在完成了[C17H20N2I][RE(EDTA)]·nH2O, [C17H20N2I]3[RE(Cit)2].nH2O及[C17H20N2I]3[RE(NTA)2].nH2O等多种配合物的合成及性质研究的基础上, 合成了3,6-二(二甲氨基)-二苯并碘六环镧反式-1,2-环己烷二胺四乙酸配合物并对其结构, 性质及抗肿瘤活性进行了研究。     

以2-(2-吡啶基)苯并噻吩为主配体的两种蓝紫光二价铂配合物的合成与性质

以2-(2-吡啶基)苯并噻吩(2-(2-pyridyl)benzothiophene,btp)作为主配体,分别以邻二氮菲[1,10]并咪唑联苯酚(2-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)phenol,ipap)和3-甲基-6-苯基咪唑[2,1-6]噻唑(3-Methyl...     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.