二苯乙烯氨基酸的合成及其性能研究

以4-碘-L-苯丙氨酸为初始原料，先将羧基和氨基进行保护、后与苯乙烯进行Heck反应，最后在碱性和酸性条件下脱除保护合成二苯乙烯氨基酸，即(E)-2-氨基-3-(4-苯乙烯基苯基)丙酸的盐酸盐（4），产率53.7%，其结构经¹H NMR、 IR和HR-MS(ESI-TOF)表征。光学性质研究结果表明：4的激发波长为312 nm，发射波长为357 nm，斯托克斯位移为45 nm，荧光量子产率为0.09。 4在甲醇溶液中存在光致顺反异构现象，反式→顺式结构转变速率常数为0.046 min^-1。     

新型吲哚衍生物的合成及其光学性质

以吲哚为原料,经Vilsmeier-Haack, Ullmannhe和Witting-Hornor反应合成了两个新型的含吲哚环共轭化合物--1,4-二(3-苯乙烯基吲哚基)苯（4a）和1,4-二(3-萘乙烯基吲哚基)苯（4b）,其结构经¹H NMR, ¹³C NMR, IR和ESI-MS表征。光学性能研究结果表明,4a和4b的λ_max分别位于330 nm和348 nm;在330 nm波长激发下,λ_em分别位于410 nm和425 nm。     

一种二苯乙烯羟胺类化合物的合成及其在糖类检测中的应用研究

以4-溴苯丙醇为初始原料,与苯乙烯经Heck反应得化合物2a;化合物2a在邻碘酰基苯甲酸的氧化作用下生成化合物3a;化合物3a在酸性条件下进行肟化反应得化合物4a;化合物4a在酸性条件下被氰基硼氢化钠还原,合成了一种二苯乙烯类羟胺化合物(5a, 20.0%),其结构经~1H NMR,~(13)C NMR, IR和LC-MS(ESI)表征。化合物5a的光学性质研究结果表明:激发波长为312 nm,发射波长为357 nm,斯托克斯位移为45 nm,荧光量子产率为0.11。以类似方法合成了氘代标记的化合物5b,化合物5a和5b能在温和条件下与聚糖类物质快速发生衍生化反应,得到高强度质谱信号的衍生产物。通过比较"轻"、"重"同位素标记的聚糖衍生物相应的质谱峰强度,可以获得具有相同化学特征的聚糖的相对含量,实现聚糖的定量分析。     

新型2-取代氨基-3-氟-4-吡啶氟硼酸钾盐的合成

以2,3-二氟-5-氯吡啶为原料,依次经取代和还原反应制得2-取代氨基-3-氟吡啶化合物(2a~2g); 2a~2g与正丁基锂及硼酸三异丙酯经有机锂化法制得相应的硼酸化合物(3a~3g); 3a~3g分别与氟化氢钾经取代反应合成了7个新型的2-取代氨基-3-氟-4-吡啶氟硼酸钾盐,其结构经¹H NMR, ¹³C NMR, IR, ESI-MS和元素分析表征。     

新型硫酮基哌嗪荧光探针的合成及其对铜(Ⅱ)的识别性能

以苯胺和三氟乙酰乙酸乙酯为原料,经环合反应制得4-三氟甲基-2(1H)喹啉酮(1);1与劳森试剂反应生成4-(三氟甲基)喹啉-2(1H)-硫酮(2);2与间隔基反应合成中间体2-[(3-氯丙基)硫基]-4-(三氟甲基)喹啉(3);将3连接到识别基团哌嗪上合成了一个新型的双荧光侧臂的探针化合物——1,4-二【3-{2-[4-(三氟甲基)喹啉]硫基}丙基】哌嗪(4),其结构经1H NMR和LC-MS表征。UV-Vis和FL研究结果表明,4的发射波长在396 nm;对Cu2+具有良好的识别作用,在1.0×10-7mol·L-1~1.0×10-4mol·L-1内可定量检测Cu2+含量。     

天然stilbene导向的取代苯乙烯基噻唑化合物的合成和生物活性

为了寻找新型结构的药物先导化合物,基于天然stilbenes骨架结构,将含氟苯基噻唑环结构与其相杂合,设计合成了一系列新型取代苯乙烯基噻唑类化合物.所有目标化合物结构均经1H NMR、13C NMR和ESI-HRMS表征确证.离体真菌抑制活性结果表明,在100 mg/L浓度下部分化合物对小麦赤霉病菌、玉米小斑病菌和黄瓜蔓枯病菌表现出中等抑制活性,其中(E)-5-溴-4-(2,6-二氟苯基)-2-(4-三氟甲基苯乙烯基)噻唑(6p)对小麦赤霉病菌的抑制率达到86.7%;采用Top1介导的DNA松散实验测试了化合物对拓扑异构酶I (Top1)的抑制活性,结果表明在50μmol·L-1浓度下,所有化合物对Top1均表现出一定程度的抑制活性,其中(E)-5-溴-4-(2,6-二氟苯基)-2-(2-氯苯乙烯基)噻唑(6k)的抑制活性较好,其在0.2μmol·L~(-1)浓度下仍对Top1呈现出一定程度的抑制活性.     

新型含氯(氟)的A_2B型咔咯化合物的合成及其光学性质

meso-(3-硝基苯基)二吡咯甲烷分别与2,6-二氯(或氟)苯甲醛经酸催化偶联反应和氧化反应合成了两个新型的A2B型咔咯化合物——10-(2,6-二氯苯基)-5,15-二(3-硝基苯基)-咔咯(3a)和10-(2,6-二氟苯基)-5,15-二(3-硝基苯基)-咔咯(3b),其结构经1H NMR,13C NMR,IR和MALDI-TOF-MS表征。采用UV-Vis和荧光光谱研究3的光学性质。结果表明:3a和3b的λmax均位于414 nm,575 nm,610 nm和642 nm附近;λem位于661 nm附近(λex=430 nm)。     

(S)-2,2,2-三氟-1-(2-甲基-1H-1-吲哚基)乙胺的不对称合成

以2-甲基吲哚为原料,在碱性条件下与α-三氟甲基醛亚胺经加成反应合成了关键中间体——含三氟甲基的(S)-叔丁基亚磺酰胺(3),收率95%,d/r99/1;3脱除保护基得(S)-2,2,2-三氟-1-(2-甲基-1H-1-吲哚基)乙胺(4),收率97%,其结构经1H NMR,13C NMR,19F NMR,FT-IR,EI-MS和HR-EI-MS确证。     

一种二苯乙烯羟胺类化合物的合成及其在糖类检测中的应用研究

以4-溴苯丙醇为初始原料,与苯乙烯经Heck反应得化合物2a;化合物2a在邻碘酰基苯甲酸的氧化作用下生成化合物3a;化合物3a在酸性条件下进行肟化反应得化合物4a;化合物4a在酸性条件下被氰基硼氢化钠还原,合成了一种二苯乙烯类羟胺化合物（5a, 20.0%）,其结构经¹H NMR, ¹³C NMR, IR和LC-MS（ESI）表征。化合物5a的光学性质研究结果表明：激发波长为312 nm,发射波长为357 nm,斯托克斯位移为45 nm,荧光量子产率为0.11。以类似方法合成了氘代标记的化合物5b,化合物5a和5b能在温和条件下与聚糖类物质快速发生衍生化反应,得到高强度质谱信号的衍生产物。通过比较“轻”、“重”同位素标记的聚糖衍生物相应的质谱峰强度,可以获得具有相同化学特征的聚糖的相对含量,实现聚糖的定量分析。     

含氟8-羟基喹啉锌配合物的合成与发光性能

设计合成了2种含三氟甲基的8-羟基喹啉衍生物配体:(E)-2-[2-(3-三氟甲基苯基)乙烯基]-8-羟基喹啉(3a)、(E)-2-[2-(4-三氟甲基苯基)乙烯基]-8-羟基喹啉(3b)及其相应的锌配合物(4a)、(4b),并由1H NMR、IR、MS、元素分析确认了其结构。通过紫外滴定观察了金属锌与配体的配合过程,测定了它们在DMF溶液中的荧光性质;荧光光谱显示化合物3a、3b在DMF溶液中的λmax分别是491nm和513nm,4a、4b的λmax分别是585nm和599nm,而且改变三氟甲基的位置可以调节配合物的发光性能。     

Switching of molecular insertion in a cyclic molecule via photo- and thermal isomerization

Two new cyclic ligands were synthesized: a ligand with two trans-azobenzene moieties and one bipyridine moiety, trans(2)-oAB-O13, and a ligand with two trans-azobenzene moieties and two bipyridine moieties, trans(2)-oAB-bpy. Both ligands underwent reversible trans-cis isomerization at the azobenzene moieties. The mole ratios of the trans(2) form:trans-cis form:cis(2) form, evaluated by (1)H NMR spectroscopy of the photostationary states prepared by 1 h illumination, were 0.13:0.27:0.60 (365 nm irradiation) and 0.41:0.47:0.12 (436 nm irradiation) for oAB-O13, and 0.18:0.12:0.70 (365 nm irradiation) and 0.36:0.43:0.21 (436 nm irradiation) for oAB-bpy. When trans(2)-oAB-O13 was mixed with Cu(I), both the bipyridine units and the polyether chains coordinated to the copper center. Addition of a noncyclic bipyridine ligand, trans(2)-oAB-2OH, afforded a bis(bipyridine)copper(I) complex, [Cu(trans(2)-oAB-O13)(trans(2)-oAB-2OH)]BF(4). The bis(bipyridine) ligand, trans(2)-oAB-bpy, formed a 1:1 complex with Cu(I), [Cu(trans(2)-oAB-bpy)]BF(4). [Cu(cis(2)-oAB-bpy)]BF(4) did not undergo the ligand substitution reaction with a noncyclic ligand with two azobenzene moieties and one bipyridine moiety, oAB, whereas its thermal isomerization in the presence of oAB caused the formation of [Cu(trans(2)-oAB-bpy)(trans(2)-oAB)]BF(4), indicating that the isomerization and ligand exchange reactions synchronized via a conformational change of the cyclic ligand.     

“哑铃状”偶氮化合物的合成与表征

从分子设计的角度出发, 合成了末端含有两个庞大基团的哑铃状偶氮化合物. 其大的末端基团一方面可以增加顺、反两种异构体之间的能垒, 有利于两种异构体的稳定存在, 另一方面由于大的末端基团的存在, 为采用AFM或高分辨STM直接观测两种异构体分子相的相互转变降低了难度.     

Theoretical Study of Halogen Effect in Isomerization of 2-Halo-[9]-annulen Anion at the DFT Level

Cis-trans isomerization of [9]-annulenanion(1) and its 2-fluoro-,2-chloro-and 2-bromo-derivatives(2,3 and 4,respectively) were investigated at the HF/6-31G* and B3LYP/6-311++G** levels of theory.Cis,cis,cis,cis structures appear more stable than their corresponding cis,cis,cis,trans-isomers.The relative height of energy barriers for cis-trans isomerization is:2cis > 1cis > 3cis > 4cis.This trend for the reverse trans-cis isomerization follows the electronegativity of the substituent at C-2(2trans > 3trans > 4trans > 1trans).     

Tetrathiafulvalenenaphthalenophanes: planar chirality and cis/trans photoisomerization

A cyclophane incorporating one 1,5-dioxynaphthalene ring system and one tetrathiafulvalene (TTF) unit bridged by [SCH(2)CH(2)O] linkages has been synthesized. In this cyclophane, the TTF unit can adopt either cis or trans configurations. In addition, the 1, 5-dioxynaphthalene ring system imposes one element of planar chirality on this cyclophane. A second element of planar chirality is introduced by the trans form of the TTF unit. Thus, the cyclophane exists in diastereoisomeric forms as three pairs of enantiomers. The enantiomeric pairs associated with the cis form of the TTF unit, as well as one of those associated with the trans form, have been isolated by crystallization, and their structures assigned in the solid state by single-crystal X-ray analyses. In solution, cis/trans isomerization occurs when either the cis or the trans form of the cyclophane is exposed to light. The photoisomerization reaction can be followed by (1)H NMR and UV-vis spectroscopies, as well as by HPLC. The photoisomerization quantum yield has been measured at two different excitation wavelengths (406 and 313 nm). In both cases, the trans --> cis process (Phi = 0.20 at 406 nm) is much more efficient than the reverse cis --> trans process (Phi = 0.030 at 406 nm). Since the absorption spectra of the trans and cis isomers are different and the quantum yield of the trans --> cis photoisomerization reaction depends on the excitation wavelength, the mole fraction of the two diastereoisomers present at the photostationary state depends on the wavelength of the exciting light. No isomerization occurs when the solutions, regardless of the mole fraction of the two diastereoisomers, are stored in the dark.     

NMR and theoretical calculations: a unified view of the cis/trans isomerization of 2-substituted thiazolidines containing peptides

The cis/trans isomerization of peptides containing the pseudoproline (4R)-thiazolidine-4-carboxylic acid Cys(Psi (R1,R2) pro) is investigated from both an experimental and a theoretical point of view by NMR and DFT calculations. A series of Ac-Cys(Psi(R1,R2) pro)-OCH3 and Ac-Cys(Psi(R1,R2) pro)-NHCH3 peptides were prepared to assess the influence of the substitution at the C2 position as well as of the amide following the thiazolidine residue. For each compound, the cis/trans ratio along with free energy, the puckering of the thiazolidine ring and the free rotational energy barrier are reported and discussed. We observe there is a pronounced effect of the C2 substituents and of the chirality upon the cis/trans ratio with the population of the cis content in the order (2R)-Cys(Psi(CH3,H) pro)<(2S)-Cys(Psi(H,CH3) pro)相似文献   

Photoisomerization and photochemistry of matrix-isolated 3-furaldehyde

3-Furaldehyde (3FA) was isolated in an argon matrix at 12 K and studied using FTIR spectroscopy and quantum chemistry. The molecule has two conformers, with trans and cis orientation of the O=C-C=C dihedral angle. At the B3LYP/6-311++G(d,p) level of theory, the trans form was computed to be ca. 4 kJ mol(-1) more stable than the cis form. The relative stability of the two conformers was explained using the natural bond orbital (NBO) method. In fair agreement with their calculated relative energies and the high barrier of rotamerization (ca. 34 kJ mol(-1) from trans to cis), the trans and cis conformers were trapped in an argon matrix from the compound room temperature gas phase in proportion ~7:1. The experimentally observed vibrational signatures of the two forms are in a good agreement with the theoretically calculated spectra. Broad-band UV-irradiation (λ > 234 nm) of the matrix-isolated compound resulted in partial trans → cis isomerization, which ended at a photostationary state with the trans/cis ratio being ca. 1.85:1. This result was interpreted based on results of time-dependent DFT calculations. Irradiation at higher energies (λ > 200 nm) led to decarbonylation of the compound, yielding furan, cyclopropene-3-carbaldehyde, and two C(3)H(4) isomers: cyclopropene and propadiene.     

含不同基团偶氮苯化合物的合成及其光致异构化性质

以苯胺或对硝基苯胺为起始原料,通过重氮偶合法合成了4种分别含有硝基、氨基和不同数目偶氮基的偶氮苯化合物(1~4),其结构经¹H NMR和FT-IR确证。研究了1~4在紫外灯(12 W)照射下随时间变化的UV-Vis谱图。结果表明：含有给电子基团(NH₂)偶氮苯的光致异构化速率较含有吸电子基团（NO₂）时更快,NO₂对分子的异构化有一定抑制作用;分子中偶氮基的数目增加时,顺反异构化过程也受到影响。     

Synthesis,characterization, and photoresponsive studies on lignin modified with (E)‐4‐(naphthalene‐1‐yl diazenyl)benzoic acid

In the present work, chromophoric system (E)‐4‐(naphthalen‐1‐yl diazenyl)benzoic acid was synthesized and incorporated into lignin core. The end hydroxyl group of lignin was modified with the free carboxyl group of the chromophoric systems by dicyclohexylcarbodiimide coupling. The products were characterized by means of UV–visible, fluorescence, FT‐IR, and NMR spectroscopic methods and subjected to photoresponsive studies. The results show that modification enhances the light absorption and light fastening properties of the chromophoric system. The photoinduced trans–cis isomerization on the newly developed photosensitive biopolymeric system and the chromophoric system were investigated. Results also show that the trans–cis photoisomerization and the reverse cis–trans thermal conversions of the photoactive groups were also assisted by the incorporation onto biopolymeric core. Copyright © 2014 John Wiley & Sons, Ltd.     

含偶氮苯生色团的短梗霉多糖衍生物的制备及性质研究

短梗霉多糖(Pullulan)是由出芽短梗霉(Aureobacidium pullulans)合成的一种细胞外水溶性大分子中性多糖。该多糖具有独特的物理化学和生物学特性,因此被广泛用于医药制造、食品包装和化妆品工业等众多领域,由于偶氮苯及其衍生物在紫外光的照射下会发生反式-顺式结构变化,而经可     

Assessment for the light-induced cis-trans isomerization of rhapontigenin and its glucoside rhaponticin by capillary electrophoresis and spectrometric methods

The light-induced cis-trans isomerization of rhapontigenin (RHA) and its glucoside rhaponticin (RHA-Glc) were evaluated under ultraviolet (UV) light irradiation. A simple and rapid capillary electrophoresis method was developed for the kinetic study of four stilbenes (both cis and trans form of RHA and RHA-Glc). These analyses were achieved by using β-cyclodextrin (β-CD) modified capillary zone electrophoresis with diode array detector (CZE-DAD). The method provided reliable separations with a short analysis time of 3 min. The purity of individual compound was checked by UV spectral comparisons with known standards, and further confirmed by (1)H and (13)C nuclear magnetic resonance (NMR) spectroscopy. Furthermore, the UV absorbance and the molar absoptivity (ε) values were determined by UV-vis spectrophotometer to be 36824 L mol(-1) cm(-1) at λ(max) 324.5 nm for trans-RHA and 43894 L mol(-1) cm(-1) at λ(max) 325 nm for trans-RHA-Glc in methanol/water mixture solution (50%, v:v), respectively. CZE, UV-vis and NMR spectroscopy studies provided similar conclusions by considering the influence of irradiation time and the influence of irradiation wavelength.