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81.
The oxidative cyclization of 5-(2-amino-5-methoxycarbonylphenyl)-substituted tricarbonyl[η4-cyclohexa-1,3-diene]iron complexes by air in protic medium provides the corresponding tricarbonyl[η4-4a,9a-dihydro-9H-carbazole]iron complexes. This procedure is applied to the total synthesis of the 3-methoxycarbonylcarbazole alkaloids mukonine and mukonidine. 相似文献
82.
Tan B Dozier A Lehmler HJ Knutson BL Rankin SE 《Langmuir : the ACS journal of surfaces and colloids》2004,20(17):6981-6984
Mesoporous silica materials with pore structures such as 2D hexagonal close packed, bicontinuous cubic, lamellar, sponge, wormhole-like, and rectangular have been made by using surfactant templating sol-gel processes. However, there are still some "intermediate" phases, in particular mesh phases, that are formed by surfactants but which have not been made into analogous silica pore structures. Here, we describe the one-step synthesis of mesoporous silica with a mesh phase pore structure. The cationic fluorinated surfactant 1,1,2,2-tetrahydroperfluorodecylpyridinium chloride (HFDePC) is used as the template. Like many fluorinated surfactants, HFDePC forms intermediate phases in water (including a mesh phase) over a wider range of compositions than do hydrocarbon surfactants. The materials produced by this technique are novel elongated particles in which the layers of the mesh phase are oriented orthogonal to the main axis of the particles. 相似文献
83.
Siloxy substituted methyl cyclopropanecar?ylates are cleaved by bromine to afford α-bromo-γ-oxoester and, after treatment with triethylamine, good yields of α,β-unsaturated γ-oxoesters. 相似文献
84.
Ammonium Chloro(thio)phosphate Betaines, a Class of Coordination-stabilized Chloro(thio)metaphosphates Ammonium chloro(thio)phosphate betaines behave like systems being in equilibrium with tert. amine and monomeric chloro(thio)metaphosphate. In solution at room temperature the amine component can be displaced by stronger donors. Mass spectra reveal the presence of ClPS2 as monomer and dimer, of ClPO2 by fragment ions of the dimer, trimer, and tetramer before reorganization takes place to form PXCl3 and P4X10 (X = O, S). Detection of ClPOS fails owing to fast equilibration into ClPO2 and ClPS2. 相似文献
85.
Ramo Marceli Fernandes Gelson Manzoni de Oliveira Ernesto Schulz Lang Ezequiel M. Vzquez‐Lpez 《无机化学与普通化学杂志》2004,630(15):2687-2691
The reaction of tellurium(IV) tetrahalides with hydrochloric and hydrobromic acid leads to the formation of (H3O)2[TeX6], which reacts subsequently with (2‐Br‐C5NH5)+X‐ to afford (2‐Br‐C5NH5)2[TeCl6] ( 1 ) and (2‐Br‐C5NH5)2[TeBr6] ( 2 ). The structure of the complex salts were analysed by X‐ray diffractometry affording the centrosymmetric space groups P21/n (monoclinic, 1 ) and P1¯ (triclinic, 2 ). Interionic hydrogen bondings hold their lattices in bidimensional supramolecular arrays not yet described in the literature. The lone electron pair of the AX6E‐system of the hexahalotellurates [TeX6]2‐ (X = Cl, Br) seems to be fully delocalized since only small octahedral deviations were observed for the anionic species. The structures of the title compounds were refined with the Te atoms occupying sites with full point symmetry, approximately m3¯m. In both cases the Te atoms enclose centers of inversion and the octahedrally dynamic structures are enforced and stabilized along the supramolecular lattices by the crystal field of the 2‐Br‐pyridinium cations. 相似文献
86.
M. Broschag T. M. Klaptke A. Schulz I. C. Tornieporth-Oetting P. Umbach P. S. White 《无机化学与普通化学杂志》1994,620(6):1132-1136
Fluorination of Cyanuric Chloride and Low-Temperature Crystal Structure of [(ClCN)3F]+[AsF6]? The low-temperature fluorination of cyanuric chloride, (ClCN)3, with F2/AsF5 in SO2F2 solution yielded the salt [(ClCN)3F]+ [AsF6]? ( 1 ) essentially in quantitative yield. Compound 1 was identified by a low-temperature single crystal X-ray structure determination: R 3 c, trigonal, a = b = 10.4246(23) Å, c = 15.1850(24) Å, V = 1429.1(4) Å 3, Z = 6, RF = 0.056, Rw = 0.076 (for significant reflections), RF = 0.088, Rw = 0.079 (for all reflections). Fluorination of neat (ClCN)3 with [NF4]+ [Sb2F11]? yielded NF3, CClF3, SbF3, N2 and traces of CF4. A qualitative scale for the oxidizing strength of the oxidative fluorinators NF4+ and (XCN)3F+ (X = H, F, Cl) has been computed ab initio. 相似文献
87.
Michael Ptzel Andreas Schulz Jürgen Liebscher Wolfgang Richter Monika Richter 《Journal of heterocyclic chemistry》1992,29(5):1209-1211
Cyclic N-cyanocarbonimidodithioesters 4 or N-aroylcarbonimidothioic acid esters 10 react regioselectively with arylhydrazines and methylhydrazine by a ring chain transformation reaction forming ω-functionalized 3-alkylthio-1,2,4-triazoles 8 and 11 or 5-alkylthio-1,2,4-triazoles 9 . 相似文献
88.
Structures of Bis(trifluoromethyl)halogeno and thiocyanato Mercurates, [Hg(CF3)2X]— (X = Br, I, SCN), and a Comparison of the Structural Parameters of the CF3 Groups [(18‐C‐6)K]2[Hg(CF3)2SCN]2 (1) and [P(CH3)(C6H5)3]2[Hg(CF3)2X]2 (X = Br (2) , I (3) ) are prepared and their crystal structures are determined. [(18‐C‐6)K]2[Hg(CF3)2SCN]2 (1) crystallizes in the monoclinic space group P21/c with Z = 2, [P(CH3)(C6H5)3]2[Hg(CF3)2Br]2 (2) in the monoclinic space group P21/n with Z = 2 and [P(CH3)(C6H5)3]2[Hg(CF3)2I]2 (3) in the triclinic space group P1¯ with Z = 1. In the solid state the three compounds form dimeric anions with planar Hg2X2 rings. The structural parameters of the Hg(CF3)2 units in the till now known bis(trifluoromethyl)halogeno mercurates are compared. In all compounds one nearly symmetric and one distorted CF3 group exist. The largest differences of the C—F bond lengths is found for [(18‐C‐6)K][Hg(CF3)2I]. This can be regarded as the experimental evidence for the properties of trifluoromethyl mercury compounds to act as excellent difluorocarbene sources in the presence of alkali iodides. 相似文献
89.
Heller B Sundermann B Buschmann H Drexler HJ You J Holzgrabe U Heller E Oehme G 《The Journal of organic chemistry》2002,67(13):4414-4422
The photocatalyzed [2 + 2 + 2]-cycloaddition of nitriles with 2 equiv of acetylene to 2-pyridines can be carried out under mild conditions and represents a valuable extension to common synthetical methods. For the ideal wavelength range (350-500 nm), lamps as well as sunlight can be used. Working at room temperature and in organic solvents such as toluene or hexane as well as in water gives satisfying results in many cases. However, it is also possible to vary the solvent and the reaction temperature of the photocatalyzed synthesis and to choose, with respect to the specific substrate, specific requirements for this particular reaction and general requirements of the method. This simple and selective method derives its potential mainly from the large variety of applicable nitriles. Suitable substrates include (functionalized) aliphatic and aromatic nitriles as well as cyanamides derived from secondary amines. 相似文献
90.
Six known metabolites, two new isocoumarins 4 and 8, and one new highly substituted benzoic acid derivative 9 were isolated from the ethyl acetate culture extract of a fungal endophyte, Scytalidium sp. In addition, another new benzoic acid 10 with an unusual 1,2-dicarbonyl side chain was indirectly identified from its methylated derivatives 10a-10d. 相似文献