共查询到20条相似文献,搜索用时 15 毫秒
1.
Alargenumberofadditionsto[6O]fullerenehavebeeninvestigated.However,mostoftheworkhaveconcentratedontheformationofthemono-additionproductS0f[60]fullerene'-Thedevelopment0fselechveroutestomultipleadductShascurrentlybecomethefrontierinthechendstryof[60]fuIlerene'~'.FollowingtheaPplicahonoftether-directedremotefunctionalizati0ntotheregi0specificformati0nofthedi-andtriadductSof[60]fullerene,F.Diederichetal6alsodescribed'awayforthedirectdifunctionalizationof[60]fullerenebasedonacyclizationreachono… 相似文献
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Ulf Lawrentz Walter Grahn Ina Dix Peter G. Jones 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(1):126-128
The title compound, C34H40N2O2S2, adopts a trans conformation. The four conjugated Csp2—Csp2 single and double bonds of the polymethinic moiety, which bridges both heterocyclic end groups and the central four-membered ring, display nearly equal bond lengths. The molecule is nearly planar, with interplanar angles between the benzothiazole end groups and the central four-membered ring of 6.9 (1) and 7.7 (1)°; the angle between the heterocyclic systems is 1.8 (1)°. The crystal packing involves π-stacking effects, with intermolecular C⃛C distances varying from 3.755 (3) to 3.991 (3) Å. 相似文献
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Justyna Mrozek Katarzyna Guzow Emilia Sikorska Wiesław Wiczk 《Central European Journal of Chemistry》2011,9(6):1046-1055
The influence of peptide sequence and Leu chirality in linear and cyclic peptides containing 3-[2-(9-anthryl)benzoxazol-5-yl]alanine on interaction with β-cyclodextrin were studied using fluorescence and NMR spectroscopy. The analysis of enthalpy-entropy compensation effect (α=1.05±0.02 and TΔS0 0=15.1±0.5 kJ mol?1) indicates that the entropic contribution connected with the solvent reorganization is the major factor governing the peptides-β-cyclodextrin complexation. Moreover, spatial orientation of guest-host molecule depends more than association constant on Leu residue configuration. However, the cyclization of the peptide chain substantially decrease the association constant with β-CD. An analysis of 2D NMR spectra reveals that inclusion complex is formed by penetration of cyclodextrin cavity from wider and narrow rims by anthryl group in the case of Box(Ant)-SPKL or anthryl and Leu residues for Box(Ant)-SPK(D)L analogue. 相似文献
5.
Taidakov I. V. Zaitsev B. E. Krasnosel’skii S. S. Borisov R. S. 《Russian Journal of General Chemistry》2011,81(10):2176-2182
Reaction of Eu(NO3)3·6H2O with 1,3-bis(1,3-dimethyl-1H-pyrazol-4-yl)-1,3-propanedione (HL) in the presence of NaOH affords the complex compound [Na(H2O)4] [EuL4]·0.775CH2Cl2 (I). The spectral (UV, IR, 1H NMR spectroscopy), and thermo-luminescent (TG-DSC-MS) properties of the complex I, as well as its fragmentation at the laser desorption ionization (LDI-MS) were studied. 相似文献
6.
Aleksandrov A. A. Elchaninov M. M. Tishina D. A. Tarakanova Yu. E. Shmanovsky M. L. 《Russian Journal of Organic Chemistry》2021,57(4):664-667
Russian Journal of Organic Chemistry - Acylation of 1,3-benzothiazol-6-amine with furan-2-carbonyl chloride in propan-2-ol gave N-(1,3-benzothiazol-6-yl)furan-2-carboxamide which was converted to... 相似文献
7.
Caliendo Giuseppe Fiorino Ferdinando Grieco Paolo Perissutti Elisa Albrizio Stefania Giordano Marialuisa Santagada Vincenzo Santini Antonello 《Structural chemistry》1998,9(2):121-127
With the aim of discovering new molecules with K+ channel modulating properties, we have synthesized analogues of cromakalim, an important molecule which shows specific affinity toward the K+ channels, by replacing the benzopyrane ring with a benzoxazine moiety. As a part of this study, we have synthesized and characterized, in solution and in the solid state as well, the compound ethyl [2,2-dimethyl-6-(2-thiazolin-2-yl)-4H-l,4-benzoxazin-3-one-4-yl]butyrate (V). This compound exhibits in the solid state the following parameters: molecular formula C19H24N2O4S, triclinic, space group
, Mw = 376.5, a = 12.581(3) Å, b = 5.485(4) Å, c = 14.612(2) Å, = 91.85(2), = 108.9(3), = 82.04(4), V = 944.7 Å3, Z = 2, d = 1.323 g·cm–3. We describe here the synthesis and discuss the solid-state conformation of this new molecule; when tested on rat aorta ring precontracted with phenylephrine, the compound showed a concentration-dependent relaxation comparable to that measured for cromakalin taken as reference drug. 相似文献
8.
The title complex,[(BBI)Mn(BDC)]n 1(BBI = 2,2'-bisbenzimidazole(C14H10N4),BDC=benzene-1,3-dicarboxylate dianion(C8H10O4)),crystallizes in the monoclinic system,space group C2/c,with a=17.822(8),b=16.181(7),c=13.355(6),β=92.112(5)°,V=3848.67(304)3,Z=8,C22H14MnN4O4,Mr=453.31,Dc=1.565 g/cm3,F(000)=1848,μ=0.725 mm-1,S=1.000,the final R=0.0310 and wR=0.0589.1 contains hydrogen bonds and π-π stacking interactions between the neighboring aryl-ring of BBI's,which helps to form a three-dimensional crystal structure. 相似文献
9.
Mihaela Mic Adrian Pîrnău Călin G. Floare Maria Miclăuș Irina Kacso Mariana Palage Mircea Bogdan 《Journal of inclusion phenomena and macrocyclic chemistry》2018,92(1-2):195-204
Spectroscopic investigation supported by molecular modeling methods has been used to describe the inclusion complex of β-cyclodextrin (β-CD) with 1-Methyl-1-({2-[4-(trifluoromethyl)phenyl]-1,3-thiazol-4-yl}methyl) piperidinium chloride (1MPTMPC) in solution and in solid state. The formation of inclusion complex between the β-CD and the 1MPTMPC has been investigated both in solution and in the solid state. Solution-state complexation between the 1MPTMPC and β-CD was established using 1H NMR spectroscopy and isothermal titration calorimetry (ITC). From the 1H NMR spectroscopic studies, 1:1 complex stoichiometry was deduced with an association constant (K) of 925 M?1. Using an independent binding model, the ITC technique provides a K value of the same order with the one determined by NMR and the thermodynamic parameters ΔH, ΔS and ΔG which reveals driving forces involved during complex formation. The formation of the solid inclusion compound was confirmed by X-ray powder diffraction and differential scanning calorimetry. The most probable conformation of the inclusion complex obtained through a molecular docking investigation corroborates well to ROESY experiment. 相似文献
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DongMeiCAI MinJieLI DaLiangLI TianPaYOU 《中国化学快报》2004,15(2):163-166
Novel C-nucleosides of tiazofurin analogue (2-[2-(hydroxymethyl)-1,3-dioxolan-5-yl] 1,3-thiazole-4-carboxamide) and its thiol-substituted derivative (2-[2-(mercaptomethyl)-1,3-dioxolan-5-yl] 1, 3-thiazole-4-carboxamide) were synthesized from methyl acrylate through a multistep procedure. Their structures were confirmed by IR, ^1HNMR, ^13CNMR and elemental analysis. 相似文献
13.
《Polyhedron》1999,18(26):3533-3544
[Tris(1,3-dithiole-2-thione-4,5-dithiolato)stannate]2−, [Q]2[Sn(C3S5)3], [tris(1,3-dithiole-2-one-4,5-dithiolato)stannate]2−, [Q]2[Sn(C3S4O)3], and [tris(1,3-dithiole-2-thione-4,5-diselenolato)stannate]2− [Q]2[Sn(C3S3Se2)3], complexes, have been synthesised and characterised. Crystal structure determinations of [Q]2[Sn(C3S5)3] (Q=1,4-dimethylpyridinium, monoclinic and orthorhombic forms; NMe4, NEt4, and PPh4) and [NEt4]2[Sn(C3S4O)3] revealed variations in the overall dianion structures. The geometry about tin in each case is essentially octahedral with the chelate bite angles in the range 80.7(5)–87.45(4)°: the range of Sn–S distances is 2.5207(18)–2.571(17) Å. A statistical analysis, carried out on the crystal structure data for the six complexes, indicated that the most critical factors in controlling the overall shape of the dianion were the distances of the Sn atom from the dithiolate ligand planes [Sn–OOP]. Interanionic S⋯S interactions, within the sum of the van der Waals’ radii for two S atoms, are affected by the size of the cation, Q; the secondary connectivity is 3-dimensional for the smallest cations, Q=1,4-dimethylpyridinium and NMe4, in chains for the somewhat larger cation, NEt4 and is absent for the still larger, PPh4 cation. 相似文献
14.
M. N. Sokolov A. V. Virovets A. V. Rogachev P. A. Abramov V. P. Fedin 《Russian Journal of Coordination Chemistry》2013,39(2):175-180
The reaction of [VO(OPr)3] (Pr is n-propyl) with hexamethyldisylthiane Me3SiSSiMe3 in the presence of β-diketones (acetylacetone (HAcac), hexafluoroacetylacetone (Hfac), and dipivaloylmethane (Dpm)), is studied. In all cases, vanadium(IV) and vanadium(III) β-diketonate complexes of different types are formed. New crystalline modification [V(Acac)3] is obtained in the reaction with HAcac. The mixedligand vanadium(III) complex of the composition [V2(Hfac)2(μ-OPr)]2 is formed with Hfac. In the presence of Dpm, the known vanadium(IV) complex [V2O2(Dpm)2(μ-OPr)2] is obtained in which two vanadyl groups VO2+ are linked by two bridging propoxy groups. The structures of all products are determined by X-ray diffraction analysis. 相似文献
15.
Various carbazoles were synthesized via [4+2] annulation of 3-(2,2-diethoxyethyl)-1,3-dicarbonyl compounds with indoles. A Brønsted acid ionic liquid, [BPy]HSO4, was proven to be effective catalyst for this reaction. The ionic liquid catalyst can be recycled three times without significant loss of its catalytic activity. 相似文献
16.
Yi SHEN Ling XIANG Yong DENG Yu Guo ZHONG Department of Medicinal Chemistry West China School of Pharmacy Sichuan University Chengdu 《中国化学快报》2006,(4)
A convenient synthesis of cis-(±) isomer 1 and trans-(±) isomer 2 of lamivudine starting from benzoyloxyacetaldehyde and l,4-dithiane-2,5-diol is described. The key steps include chlorination of oxathiolane lactol 5 by SOCl2/DMF, followed by coupling with silylated N4-acetylcytosine and deprotection. The overall yield was 42.6 % and 20.1 %, respectively. 相似文献
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1,2-(1-Acridin-10'-y1-2-aza-2-methylprop-1,3-ylene)fullerene was synthesized firstly and characterized byUV-Vis,~1H NMR,~(13)C NMR and electrospray ionization mass spectroscopy,which is capable of forming a stablecomplex with zinc tetraphenylporphyrin via the axial ligafion.The steady state fluorescence studies show efficientquenching of the zinc tetraphenylporphyrin emission upon axial coordination of acridine attached to C_(60). 相似文献
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M. Carmen Maestro José Antonio Fernández-Salas José L. García Ruano Oney O. Ramírez-Rodríguez Ramiro Araya-Maturana 《Tetrahedron》2012,68(22):4129-4137
The ability of a homochiral sulfinyl group at the dienophile to act as a remote stereocontrol inductor in the Diels–Alder reaction with cyclopentadiene has been evaluated. High pressure conditions were required for the reactions of (S)-2-(p-tolylsulfinyl)styrenes 3–5 (E-1,2-disubstituted double bond) and 6–8 (1,1-disubstituted double bond). A good facial selectivity and total endo selectivity were attained with 1,1-disubstitued dienophiles, though the 1,2-disubstituted ones afforded poorer results. In contrast, (S)-[2-(p-tolylsulfinyl)phenyl] vinyl ketones 9–11 reacted readily at low temperature (?40 °C) with complete endo selectivity and high facial selectivity in the presence of Yb(OTf)3 as a chelating reagent of sulfinyl and carbonyl oxygen atoms. Concerning furan reactions, β-trifluoromethyl enone 14 afforded Diels–Alder adducts with high facial selectivity in the presence of the Lewis acid, but β-non-substituted enones 9 and 12 yielded products of furan conjugate addition to the double bond. 相似文献
19.
Russian Journal of General Chemistry - Some novel (E)-2-cyano-3-(substituted phenyl/dimethylamino)-N′-[1-(pyren-3-yl)]acrylohydrazides and benzochromenone-2-carbohydrazide derivatives were... 相似文献
20.
O. U. Nesterova A. S. Pugachova M. V. Voevudsky O. V. Krischik V. I. Musatov 《Chemistry of Heterocyclic Compounds》2011,46(12):1520-1526
Cyclization of the hydrazide of 5-ethoxycarbonyl-2,6-dimethylpyridine-3-carboxylic acid by acylation with aromatic or aliphatic
acid chlorides with subsequent boiling in POCl3 or heating in orthoformic acid gave the corresponding ethyl 2,6-dimethyl-5-(5-R-1,3,4-oxadiazol-2-yl)pyridine-3-carboxylate.
The cyclization of the reaction products with hydrazine hydrate has been studied. Cyclization of the dihydrazide of 2,6-dimethyl-3,5-pyridinedicarboxylic
acid under analogous conditions gave only 3,5-bis-(5-R-1,3,4-oxadiazol-2-yl)-2,6-dimethylpyridines, containing R = 2-FC6H4, H. 相似文献