Seven-membered vibsane-type diterpenes with a 5,10-cis relationship from Viburnum awabuki

New five seven-membered vibsane-type diterpenes named 5-epi-vibsanin C, 5-epi-vibsanin H, 5-epi-vibsanin K, 18-O-methyl-5-epi-vibsanin K and 5-epi-vibsanin E have been isolated from the leaves of Viburnum awabuki (Caplifoliaceae). Their structures have been elucidated by analyses of spectroscopic data and comparison of their spectral data with those of the previously known seven-membered vibsane-type diterpenes. The occurrence of these seven-membered vibsane-type diterpenes with a cis relationship on the C-5 and C-10 positions in nature have been predicted by conformational analysis of vibsanin B, an eleven-membered vibsane-type diterpene. Vibsanin C, 5-epi-vibsanin C and 5-epi-vibsanin H exhibited moderate cytotoxic activities on KB cells.     

含二茂铁基的硫代碳酰腙和缩氨基硫脲的合成

硫代碳酰腙和氨基硫脲衍生物具有一定的生理活性,可作为某些金属离子的特效试剂,本文报道在乙醇-醋酸介质中通过取代氨基硫脲,硫代碳酰腙与不同的二茂铁衍生物缩合,合成了新的缩氨基硫脲和硫代碳酰腙衍生物.     

Tuning the selectivity/specificity of fluorescent metal ion sensors based on N2S2 pyridine-containing macrocyclic ligands by changing the fluorogenic subunit: spectrofluorimetric and metal ion binding studies

Two new fluorescent chemosensors for metal ions have been synthesized and characterized, and their photophysical properties have been explored; they are the macrocycles 5-(2-quinolinylmethyl)-2,8-dithia-5-aza-2,6-pyridinophane (L5) and 5-(5-chloro-8-hydroxyquinolinylmethyl)-2,8-dithia-5-aza-2,6-pyridinophane (L6). Both systems have a pyridyl-thioether-containing 12-membered macrocycle as a binding site. The coordination properties of these two ligands toward CuII, ZnII, CdII, HgII, and PbII have been studied in MeCN/H2O (1:1 v/v) and MeCN solutions and in the solid state. The stoichiometry of the species formed at 25 degrees C have been determined from absorption, fluorescence, and potentiometric titrations. The complexes [CuL5](ClO4)(2).1/2MeCN, [ZnL5(H2O)](ClO4)2, [HgL5(MeCN)](ClO4)2, [PbL5(ClO4)2], [Cu3(5-Cl-8-HDQH-1)(L6H-1)2](ClO4)(3).7.5H2O (HDQ=hydroxyquinoline), and [Cu(L6)2](BF4)(2).2MeNO2 have also been characterized by X-ray crystallography. A specific CHEF-type response of L5 and L6 to the presence of ZnII and CdII, respectively, has been observed at about pH 7.0 in MeCN/H2O (1:1 v/v) solutions.     

Skeletal diverse synthesis of N-fused polycyclic heterocycles via the sequence of Ugi-type MCR and CuI-catalyzed coupling/tandem Pictet-Spengler reaction

Several diversity-oriented syntheses of N-fused polycyclic heterocycles have been demonstrated but most of them are based on point diversity within the same library and usually involve time-consuming sequential multistep syntheses, which also suffer from low yields and/or poor precursor scopes. We have developed a new strategy for the syntheses of skeletal diverse N-fused polycyclic compounds via an Ugi-type MCR followed by a CuI-catalyzed coupling reaction or tandem Pictet-Spengler reaction. This two-step sequence provides eight distinct skeleton of fused {6-5-5-6}, {5-5-5-6}, {6-5-6-6}, and {5-5-6-6} ring systems that have applications in medicinal chemistry and chemical genetics too.     

铁双(双戊二烯巯基)环戊二烯基钛(Ⅳ), 锆(Ⅳ)的合成和结构表征

1, 1'-二巯基二茂铁分别和二氯二茂钛(Ⅳ), 二氯二茂锆(Ⅳ)在无水苯中在氨基钠存在下反应, 合成了两个未见报道的化合物Fe(η^5-C5H4S)2M(η^5-C5H5)Cl[M=Ti, Zr]。它们的组成和结构经元素分析,IR和^1H NMR得到证实。     

Mono(dinitrogen) and carbon monoxide adducts of bis(cyclopentadienyl) titanium sandwiches

The silyl-substituted titanocene complex, (eta5-C5Me4SiMe2Ph)2Ti, coordinates dinitrogen upon cooling to -35 degrees C to yield an unprecedented example of a mono(dinitrogen) complex of a substituted bis(cyclopentadienyl) titanium compound, (eta5-C5Me4SiMe2Ph)2Ti(N2). Analogous monocarbonyl derivatives, (eta5-C5Me4R)2Ti(CO) (R = SiMe3, SiMe2Ph, CHMe2), have been prepared by mixing the dicarbonyl compounds with the corresponding sandwiches. Both (eta5-C5Me4SiMe2Ph)2Ti(N2) and (eta5-C5Me4SiMe2Ph)2Ti(CO) have been characterized by X-ray diffraction, and mixed N2-CO titanocene complexes have also been observed by in situ IR spectroscopy.     

Structure and stability of B5C and C5B clusters

Geometry optimizations and vibrational frequencies of B5C and C5B clusters were calculated with the Becke-3LYP method using the 6-311+G(d) basis set and some stable configurations of B5C and C5B clusters have been found. The most stable structure of B5C is a planar six-membered ring. However, for C5B clusters, the most stable structure is linear with a boron atom in position 3. Various configurations of B5C clusters containing three-membered boron rings have predominance in energy, whereas various configurations of C5B clusters containing three-membered carbon rings are disadvantageous in energy. In B5C clusters, isomer2 can be converted into isomer1 by surmounting an energy barrier of 43.83 kJ.mol(-1). In C5B clusters, the conversions of isomer5 into isomer2 and isomer7 into isomer2 have energy barriers of 19.66 and 20.57 kJ.mol(-1), respectively.     

Synthesis and structure of 1-zirconacyclopent-3-yne complexes without substituents adjacent to the triple bond

Five-membered metallacyclic alkynes that have no substituents adjacent to the triple bond have been synthesized, isolated, and structurally characterized. Zirconocene dichlorides, Cp'2ZrCl2 (Cp' = C5H5, C5H4-t-Bu), reacted with 1,4-dichlorobut-2-yne in the presence of magnesium to give 1-zirconacyclopent-3-yne compounds (5 (a) Cp' = C5H5, (b) Cp' = C5H4-t-Bu) that have a -CH2CCCH2- moiety in good yields. They are stable enough to be isolated in a pure form, despite the absence of substituents. 5a reacted with an equimolar amount of Cp2Zr(but-1-ene)(PMe3) to produce a bimetallic complex in which the zirconacyclopentyne coordinates to the other zirconocene moiety as an alkyne.     

聚酰胺-胺型树枝状高分子水溶液的表面活性

树枝状化合物是一类三维的、高度有序的新型高分子.与传统高分子相比,这类化合物在合成时,可以在分子水平上严格控制,设计分子大小、形状、结构和功能基团,产物一般高度对称,单分散性好.因而具有广泛的潜在用途^[1,2].近年来,已引起广大化学工作者的重视.     

Carbon-13 nmr spectra of the tRNA “wobble” nucleosides 5-carboxymethyl-, 5-carbomethoxymethyl-, and 5-carbamoylmethyluridine

The ¹³C nmr chemical shifts have been measured for 5-carboxymethyluracil 2 , 5-carbo-methoxymethyluracil 3 , their 2-thio derivatives 4 and 5 , respectively, as well as of the three β-D-ribonucleosides, 5-carboxymethyluridine 7 , 5-carbomethoxymethyluridine 8 , and 5-carbamoyl-methyluridine 9 . In addition, the ¹³C-¹H coupling constants for 2 and 7 have, also been obtained.     

磷酸钴铝(CoAPO-5)分子筛的合成、结构及其性质研究

继文献^[1]的研究之后,我们又合成了CoAPO-5分子筛,Wilson,S.T.^[2]曾提到他们合成的CoAPO-5是不纯的,而我们得到了CoAPO-5的纯相,用X射线衍射、电子探针、红外光谱等方法进行了结构研究.并测定了CoAPO-5分子筛的晶胞参数、化学组成,同时对分子筛的吸附性能、热稳定性、酸性等进行了研究。     

Nucleophilic Substitution in 4-Bromo-5-nitrophthalodinitrile: VII. Synthesis and Properties of Phenylthio-substituted Phthalocyanine Metal Complexes

New phenylthio-substituted phthalodinitriles have been synthesized: 5-amino-4-phenylthio-, 5-acetylamino-4-phenylthio-, 5-octanoylamino-4-phenylthio-, 5-phenoxy-4-phenylthio-, 5-(4-carboxyphenoxy)-4-phenylthio-, 5-(4-tert-butylphenoxy)-4-phenylthio-, and 4,5-bis(phenylthio)phthalodinitriles. Their complexes with metals have been prepared and examined by spectral methods.     

An improved synthesis of some 5-substituted indolizines using regiospecific lithiation

Various 2-substituted indolizines can be directly and selectively lithiated in the 5 position and subsequent reactions with different electrophiles lead to some novel classes of indolizines. In particular, previously unknown 5-formyl- and 5-iodoindolizine have been prepared by this way and the molecular structure of 5-formyl-2- phenylindolizine was confirmed by X-Ray analysis. The reactivity of the 5-CHO- and 5- COPh groups toward some nucleophiles has been examined, and some additional classes of derivatives (oximes and alcohols) have been obtained. The possibility of Suzuki cross- coupling of 5-iodoindolizines and boronic acids was proven.     

溴乙烷光电离解离的理论计算和实验

分子的电离电势、键能和离子的标准生成焓等都是非常重要的物理化学数据,它们对化学反应机理等研究有很大帮助,精确测定离子的出现势,就可以获得这些热力学常数.迄今为止,有关溴乙烷(Ｃ2Ｈ5Ｂｒ)电离解离过程的研究已有若干报导[1-3],但这些结果均是在常温条件下,用电子轰击电离、彭宁电离或真空紫外灯辐照等方法获得的,由于常伴有热带效应、离子分子反应、离子对形成等过程[4],其结果的准确性往往较差.本文首次报导使用同步辐射光源对Ｃ2Ｈ5Ｂｒ进行光电离解离研究.通过准确测量母体离子以及几种主要碎片离子的出现势,结合已有的公认的热力…     

Functionalized pyridylboronic acids and their Suzuki cross-coupling reactions to yield novel heteroarylpyridines

2-Bromo-5-pyridylboronic acid 2a, 2-chloro-5-pyridylboronic acid 2b, 2-methoxy-5-pyridylboronic acid 2c, and 5-chloro-2-methoxy-4-pyridylboronic acid 4 have been synthesized and shown to undergo palladium-catalyzed cross-coupling reactions with heteroaryl bromides to yield novel heteroarylpyridine derivatives. The X-ray crystal structures of 2a and 2b have been obtained.     

MO-berechnungen an heterocyclen—VII : Tautomerieprobleme an substituierten 1,3,8-triazaindolizinen

The electronic spectra of some derivatives of 5-hydroxy-7-methyl-1,3,8-triazaindolizine have been calculated with the PPP-procedure. With the electronic spectra and heats of atomization the tautomeric structures of the compounds 6-ch]or-5-hydroxy-7-methyl-1,3,8-triazaindolizine, 6-brom-5-hydroxy-7-methyl-1,3,8-triazaindolizine, 6-carboxy-5-hydroxy-7-methyl-1,3,8-triazaindolizine, 2-carboxy-5-hydroxy-7-methyl-1,3,8-triazaindolizine, 2-mercapto-5-hydroxy-7-methyl-1,3,8-triazaind and 5-amino-7-methyl-1,3,8-triazaindolizine are discussed. The possible structures of the compounds 5-hydroxy-7-methyl-1,3,8-triazaindolizine, 5-hydroxy-7-methyl-1,2,8-triazaindolizine and 5-hydroxy-7-methyl-1,2,3,8-tetrazaindolizine depending on the pH-value of the solution have been investigated.     

Effects of Side-Chain Substituents in Benzo-15-Crown-5 on Lithium Extraction

Chloroform–water extraction systems have been studied using crown-ethers as extracting agents, namely: benzo-15-crown-5 (B15C5), 2,3-naphtho-15-crown-5 (N15C5), 4′-nitro-benzo-15-crown-5 (NO₂B15C5), 4′-tert-butyl-benzo-15-crown-5 (TBB15C5), and 4′-acetyl-benzo-15-crown-5 (AcB15C5). Extraction isotherms of these systems have been obtained, and an attempt made to elucidate the effect of the structure of extracting agent on extraction characteristics. IR-spectroscopic studies have been performed for selected crown-ethers and their complexes in crystalline form and in chloroform solutions, namely, for N15C5, NO₂B15C5, AcB15C5, and B15C5. The complexes LiN15C5H₂OClO₄ (1), LiN15C5H₂OI (2), LiNO₂B15C5H₂OI (3), LiAcB15C5H₂OI (4), and LiTBB15C5H₂OI (5) have been isolated for the first time and characterized by IR spectroscopy. Single-crystal X-ray data have been obtained for complexes 1–3.     

Synthesis,characterization, and in vitro biological studies of some novel pyran fused pyrimidone derivatives

A variety of pyrano[2,3‐d]pyrimidine‐5‐one derivatives 5 , 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 6 , 6a , 6b , 6c , 6d , 6e , 6f , 6g , 6h , 6i , 6j have been synthesized from 6‐amino‐4‐(substituted phenyl)‐5‐cyano‐3‐methyl‐1‐phenyl‐1,4‐dihydropyrano[2,3‐c]pyrazole derivatives 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j via cyclization using formic acid and acetic acid. All the newly synthesized compounds have been characterized by IR, ¹H NMR, ¹³C NMR, and elemental analysis. All the synthesized compounds have been screened for antibacterial, antifungal and antitubercular activity. J. Heterocyclic Chem., (2012).     

MAPO-5分子筛的合成、结构及其性质的研究

用水热法合成了磷酸镁铝分子筛(MAPO-5),以X射线衍射、电子探针、核磁共振及红外光谱等方法进行了结构分析,并测定了MAPO-5分子筛的晶胞参数、化学组成,同时对分子筛的吸附性能、热稳定性、酸性等进行了研究。证明镁进入了分子筛的骨架。     

C2H5C60H的加成产物的结构和光谱性质的量子化学研究

用INDO系列方法对C₂H₅C₆₀H的1,2-加成和1,4-加成两种产物异构体的结构进行了理论研究,结果表明1,2-C₂H₅C₆₀H具有Cs对称性,1,4-C₂H₅C₆₀H没有任何对称性,1,2-C₂H₅C₆₀H的总能量比1,4-C₂H₅C₆₀H的低。以此优化构型为基础,计算了两种产物异构体的电子吸收光谱,讨论了其光谱红移的原因,同时对产物的NMR谱进行了探讨。