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31.
N. Suryakiran 《Tetrahedron letters》2007,48(5):877-881
The synthesis of α-halo β-keto-sulfones using potassium halide and hydrogen peroxide as a chemoselective mono halogenation reagent and the synthesis of α,α-symmetrical and asymmetrical dihalo β-keto-sulfones and α-halo, α-alkyl and β-keto-sulfones is described. Base induced cleavage of α-halo β-keto-sulfones, α,α-dihalo β-keto-sulfones, and α-halo, α-alkyl β-keto-sulfones afforded the corresponding halomethyl sulfones, dihalomethyl sulfones and haloalkyl sulfones. 相似文献
32.
Single crystals of [CuCl0.85Br0.15(C6H4N3CH2=CH2)] (I) were obtained by alternating current electrochemical synthesis; their X-ray structural investigation has been carried
out (DARCh automatic diffractometer, MoK
α radiation, θ/2θ scanning; 1460 reflections with F ≥ 4σ(F), R = 0.0517). The crystals are monoclinic, their space group is P21/c, a = 7.292(3) Å, b = 17.947(8) Å, c = 7.398(4) Å, β = 93.56(4)°, V = 966(1) Å3, Z = 4). Complex I is close in structure to the previously investigated compound [CuCl(C6H4N3CH2=CH2)] (II). In both structures, the trigonal-pyramidal surroundings of the copper atom include two halide atoms (one is apical),
a nitrogen atom, and a C=C group. The Cu2X2 dimers are associated into {[Cu2X2(C6H5N3CH2=CH2)]}n layers due to the bridging function of the 1-allylbenzotriazole molecule. In spite of the similar coordination polyhedra
of the metal atoms and identical bridging function of the ligand molecule in I and II, the differences in the conformation
parameters of the allyl group π-coordinated by the copper(I) atom (trans-like in I and cis-like in II) caused by the presence
of bromine atoms in the coordination sphere predetermine different structures of the organometallic [Cu2X2(C6H5N3CH2=CH2)]4 tetramer subunits in the layers and, as a consequence, formation of different crystal structures.
Original Russian Text Copyright ? 2005 by E. A. Goreshnik, B. M. Mykhalichko, and V. N. Davydov
__________
Translated from Zhurnal Strukturnoi Khimii, Vol. 46, No. 1, pp. 174–178, January–February, 2005. 相似文献
33.
Naoki Kakusawa 《Journal of organometallic chemistry》2005,690(12):2956-2966
The reaction of ethynylstibanes (1a-g) with vinyl halides or triflate in the presence of a palladium catalyst led to the formation of cross-coupling products (5a-g, 10-12) in good to moderate yield, along with homo-coupling products (6a-g). A similar reaction of ethynyldiphenylstibane (1a) with aryl iodides (13a-i) also gave cross-coupling products (14a-i), although the yields were relatively low. The yields of the cross-coupling products were highly dependent on the nature of the solvent employed, and good results were obtained when the reaction was carried out in HMPA or amines such as diethylamine and morpholine. The results imply that HMPA and amine used as solvents facilitate transmetallation of the ethynyl group on 1 to the palladium by intermolecular coordination between antimony and oxygen (for HMPA) or nitrogen (for amine). 相似文献
34.
Satish N. Dighe Ravindra V. Bhattad Raghunath R. Kulkarni Kishor S. Jain 《合成通讯》2013,43(23):3522-3527
The synergy of the combined use of DMSO and an ionic liquid viz. (bbim)+Br? has brought about a rapid and efficient esterification of sodium carboxylates with acyl and alkyl halides under ambient conditions in excellent isolated yields (90–95%) in short reaction times (12–40 min). 相似文献
35.
Solid state NMR spectroscopy is swiftly emerging as useful tool to characterize the structure, composition and dynamic properties of lead halide perovskites. On the other hand, interpretation of solid state NMR signatures is often challenging, because of the potential presence of many overlapping signals in small range of chemical shifts, hence complicating the extraction of detailed structural features. Here, we demonstrate the reliability of periodic Density Functional Theory in providing theoretical support for the NMR characterization of halide perovskite compounds, considering nuclei with spin I=1/2. For light 1H and 13C nuclei, we predict NMR chemical shifts in good agreement with experiment, further highlighting the effects of motional narrowing. Accurate prediction of the NMR response of 207Pb nuclei is comparably more challenging, but we successfully reproduce the downshift in frequency when changing the halide composition from pure iodine to pure bromine. Furthermore, we confirm NMR as ideal tool to study mixed halide perovskite compounds, currently at the limelight for tandem solar cells and color-tunable light emission. 相似文献
36.
Synthesis of diaryl sulfides via nickel ferrite‐catalysed C─S bond formation in green media
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NiFe2O4 magnetic nanoparticles (MNPs) were synthesized, characterized and applied as an air‐stable, inexpensive and magnetically separable nanocatalyst for the synthesis of structurally diverse sulfides. Efficient methodologies were developed for the synthesis of unsymmetric diaryl sulfides via odourless and one‐pot reactions of triphenyltin chloride/S8 or arylboronic acid/S8 as thiolating agents with aryl halides or nitroarenes as starting materials in the presence of base (K2CO3 or NaOH) and NiFe2O4 MNPs as a catalyst in water or poly (ethylene glycol) as solvent at 80–110 °C. Free from ligand and the unpleasant smell of thiols and with the use of magnetically reusable nanocatalyst, green solvents and commercially available and cheap sulfur source and starting materials, these methods are more eco‐friendly and practical than available protocols for the synthesis of sulfides. 相似文献
37.
Li-Dan Lin Prof. Dr. Dan Zhao Prof. Dr. Xin-Xiong Li Prof. Dr. Shou-Tian Zheng 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(2):442-453
During the past decade, research on the design and synthesis of zeolite-like metal–organic frameworks (ZMOFs) has developed greatly. As an important subclass of ZMOFs, zeolite-like cluster organic frameworks (ZCOFs) built from 4-connected metal-cluster secondary building units (SBUs) and appropriate linear organic ligand bridges have attracted sustained interest, because such materials not only integrate the merits of inorganic zeolites, ZMOFs, and metal clusters, including interesting topologies, high surface areas, extra-large cavities and channels, structural tunability, and unique physicochemical properties from various metal clusters, but also open up a new avenue to design and fabricate hybrid zeolite-like materials that have many potential applications in material sciences. In this review, recent developments in ZCOFs are summarized by classifying the ZCOFs into four categories according to the composition of the SBUs: 1) ZCOFs based on metal–halide cluster SBUs, 2) ZCOFs based on metal–oxygen cluster SBUs, 3) ZCOFs based on metal–chalcogen cluster SBUs, and 4) ZCOFs based on mixed types of metal-cluster SBUs. Besides, challenges associated with the design and synthesis of ZCOFs and the vast potential of this area are also discussed. 相似文献
38.
Polyethylene glycols (PEGs) with different molecular weights (Mw = 200, 400, 1000) were phosphorylated to their bis‐diphenyl phosphinite derivatives as stable solids which are melted in the range 140–160°C. These phosphorylated PEGs were used as ligands and reducing agents to generate nano‐Pd(0) catalysts in 2.5–8.3 nm. The nano‐Pd(0) particles supported on phosphorylated PEG200 were applied for the efficient Heck–Mizoroki carbon–carbon coupling reactions of ArX (X = Cl, Br, I) at 80–100°C under solvent‐free conditions and for the Suzuki–Miyaura coupling reaction in ethanol at 70°C. The catalyst was recycled easily and reused for several runs. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
39.
Diaryl ditellurides were conveniently reduced by a system consisting of samarium and zirconium tetrachloride in tetrahydrofuran to produce samarium aryltellurolates. This new tellurolate anion species reacted smoothly with α, β-unsaturated esters (and nitriles) to give β-telluroesters (and nitriles) in good yields. 相似文献
40.
Abstract An overview of results on microscopic properties, implantation features and dynamics of Fe ions implanted into Si, Ge and ZnS as investigated with in beam Mößbauer spectroscopy(IBMS) is given. Potential and limitations of the method are discussed. 相似文献