bluuebunny/crossref_metadata_2025 huggingface dataset:
Triethyloxonium Tetrafluoroborate/1,2-Dimethoxyethane – a Versatile Substitute for Trimethyloxonium Tetrafluoroborate in O-Methylation Reactions
Authors: Ritter Andrea , Poschenrieder Hermann , Bracher Franz
Published: February 2015

The triethyloxonium tetrafluoroborate/1,2-dimethoxyethane (TEO/DME) mixture is a versatile and cheap substitute for trimethyloxonium tetrafluoroborate in O-methylations of pyrrolin-2-ones, quinolones, acridones, and 1-oxo-β -carbolines. Undesired O-ethylation can be avoided by preincubation of triethyloxonium tetrafluoroborate and 1,2-dimethoxyethane for 1 h, prior to addition of the substrate. In the course of these investigations it was found that the structures assigned to the alkaloids taraxacine A and B are erroneous.
Phytochemical Constituents and Biological Activities of Origanum syriacum
Authors: El-Desouky Samy K. , Ibrahim Lamyaa F. , Kawashty Salwa A. , El-Ansari Mohamed A. , Kim Yeong Suk , Chong Han-Soo , Kim Ok kyung , Kim Young-Kyoon
Published: February 2015

The cytotoxicity of the methanol extract of Origanum syriacum against human cerivical adenocarcinoma, Hela cells, was evaluated by the MTT assay. From the crude extract, a new flavone glycoside, acacetin-7-O-[2´´-O-α-L-rhamnopyranosyl-6´´-O-β -D-glucopyranosyl]-β -D-glucopyranoside (1), together with the ten known flavonoids luteolin (2), apigenin (3), luteolin-6-C-glucoside (4), luteolin-3´-methylether-6-C-glucoside (5), luteolin-7,4´-dimethyether-6-C-glucoside (6), apigenin-7- methylether-6-C-glucoside (7), apigenin-7-O-glucoside (8), diosmetin-7-O-glucoside (9), acacetin- 7-O-glucoside (10) and acacetin-7-O-rutinoside (11), was isolated from the methanol extract of the aerial parts of Origanum syriacum. The structure elucidation of the isolated compounds was performed by spectroscopic and chromatographic methods.
High-pressure – High-temperature Synthesis of Na6MnO4
Authors: Pfeiffer Steffen , Jansen Martin
Published: February 2015

The title compound has been synthesized under 4 GPa and at 500 ◦C from Na2O andMnO as starting materials. Rietveld refinement of the X-ray powder pattern indicates that Na6MnO4 is isostructural to Na6ZnO4 and thus is representing the second manifestation of an “isolated” [MnO4]6− anion after Na14Mn2O9. The compound crystallizes in the hexagonal system in space group P63mc (no. 186) with a = 7.6631(2) and c = 5.9013(2) ° A, V = 300.1 °A3, and Z = 2.
Syntheses, Crystal Structures and an Overview of Alkali Metal Maleates
Authors: Fleck Michel , Bohatý Ladislav
Published: February 2015

The crystal structures of four alkali salts of maleic acid have been determined by single crystal X-ray diffraction: crystals of rubidium hydrogen maleate, RbH(C4H2O4), are very nearly centrosymmetrical, i. e., only one hydrogen atom position in the crystal structure violates the centrosymmetry. Thus, the space group is Pbc21 rather than Pbcm. The compound is isotypic with potassium hydrogen maleate, KH(C4H2O4), which has previously been described in space group Pbcm. It has been reinvestigated to prove that the correct space group is also Pbc21. The isotypic pair of rubidium hydrogen maleate maleic acid, RbH(C4H2O4) H2(C4H2O4), and caesium hydrogen maleate maleic acid, CsH(C4H2O4)H2(C4H2O4), crystallise in the triclinic space group P1̄. The geometry of the maleate units in these compounds corresponds well to data of other metal maleates. The only significant variation, concerning the intra-anionic hydrogen bond, is discussed. Furthermore, an overview of previously reported metal maleate structures is given, with special regard to the symmetry of the intramolecular hydrogen bond.
Synthesis and Characterization of Cyclotriphosphazenes Bearing Six Bile Acid Arms
Authors: Fantin Giancarlo , Fogagnolo Marco , Giovannini Pier Paolo
Published: February 2015

Four novel cyclotriphosphazene bile acid derivatives (1 - 4) were prepared starting from hexakis[4- (chloromethyl)phenoxy]cyclotriphosphazene (8) as the scaffold. The structures of the compounds were defined by elemental analysis, IR and 1H, 13C and 31P NMR spectroscopy.
Single Crystal Structure of the Divalent Europium Chloroapatite Eu5(PO4)3Cl
Authors: Yahia Hamdi Ben , Rodewald Ute Ch. , Pöttgen Rainer
Published: February 2015

The chloroapatite Eu5(PO4)3Cl has been synthesized by a solid-state reaction route using a salt flux. Its structure has been solved and refined from single crystal X-ray data: apatite type, P63/m, a = 988.36(4), c = 720.32(3) pm, Z = 2, R(F) = 0.021 and wR(F2) = 0.063 for 748 unique reflections and 40 variables. The Eu5(PO4)3Cl structure contains isolated (PO4)3− tetrahedra and two crystallographically independent divalent europium sites. The Eu12+ ion at the 4 f position is located in a distorted tri-capped trigonal prism whereas the Eu22+ ion at the 6h position is located in a strongly distorted square anti-prism. The chloride ions have octahedral europium coordination (307 pm Eu-Cl).
Synthesis and Reactions of Ferrocenyl-capped Long-chain Alkynes
Authors: Blömker Tobias , Böckmann Philipp , Kehr Gerald , Fröhlich Roland , Erker Gerhard
Published: February 2015

Alkyl-substituted acetylenes and diacetylenes with terminal ferrocenyl groups were synthesised starting from ferrocene. The reactivity of the triple bonds in the resulting compounds was used to prepare cobalt-alkyne complexes. Cyclotrimerisation of the monoacetylene resulted in a hexa-substituted benzene derivative with six pending ferrocenyl groups.
Skeleton Diversity by Cyclopropanation of Tricyclic Acylenamines
Authors: Zöllinger Michael , Mayer Peter , Lindel Thomas
Published: February 2015

Aiming at the structural diversification of phakellin- and isophakellin-type pyrrole-imidazole alkaloids on the skeleton level, the reaction of dipyrrolopyrazinones and pyrroloindolizines with dichlorocarbene was investigated. Conversions resulted in ring expansion affording novel chlorinated and brominated dipyrroloazepinones, pyridopyrroloazepinones, and dipyrrolopyrazinones. Structures of the tetracyclic products with hitherto unknown architectures have been secured by X-ray analyses.
The Synthesis of Carboxy- and Cyano-substituted 4H-Imidazoles: Redoxactive Ligands as Starting Materials for Metal-Metal Multiply Bonded Compounds and Heterobimetallic Complexes
Authors: Matschke Martin , Blumhoff Jorg , Beckert Rainer , Imhof Wolfgang
Published: February 2015

Cyanobenzoic acids proved to be suitable starting materials for the transformation into multifunctional products of the 4H-imidazole type. Employing two different pathways, the new derivatives 1b-d which possess carboxy/cyano groups were synthesized. In addition, derivative 1d formed the basis for the construction of novel bis-4H-imidazoles with two different complexation spheres. The structures of all new derivatives were confirmed by NMR spectroscopy, mass spectrometry, elemental analysis, UV/Vis-/fluorescence spectroscopy, and electrochemical measurements.
Ex Chiral Pool Synthesis from a Highly Methyl-branched Wax Ester and Biological Properties of (+)-Capensifuranone
Authors: Galeyeva Yana , Morr Michael , Sasse Florenz , Diestel Randi , Laschat Sabine , Baro Angelika , Frey Wolfgang
Published: February 2015

Unnatural (+)-capensifuranone (+)-2 and its epimer (-)-5-epi-capensifuranone 6 were prepared from enantiopure methyl-branched aldehyde 4, employing cyclisation with 3-bromomethacrylic acid to 4-bromofuranones 5a,b followed by Negishi cross coupling. Compound 4 was obtained from the preen-gland wax-derived ester 3 after ozonolysis and reductive work-up. The configuration of 6 was determined via the X-ray crystal structure analysis of a derivative 10. Compounds (+)-2, 5a,b and 6 showed cytotoxic activity against L-929 mouse fibroblasts, and KB-3-1 HeLa and U-937 lymphoma cells.
Asymmetric Synthesis of Pyrido[1,2-c]pyrimidinones
Authors: Pabel Jörg , Wadenstorfer Elmar , Wanner Klaus T.
Published: February 2015

“Asymmetric Electrophilic α-Amidoalkylation” reactions with a chiral alkylaminocarbonyl unit as chiral auxiliary are used for the stereoselective synthesis of 2-substituted piperidine derivatives. Intramolecular condensation of the nitrogen of the aminocarbonyl group with the keto function present in the newly introduced side chain of the amidoalkylation products results in the formation of hexahydropyrido[1,2-c]pyrimidinones. After reduction and removal of the N-alkyl moiety of the chiral auxiliary the target compounds, enantiopure octahydro-1H-pyrido[1,2-c]pyrimidin-1-ones, are obtained.
Sultam and Sultim Structures, Part 5 [1]. Weak Hydrogen Bonds in Molecular Networks of 2-Hetaryl-3-oxosultams in Comparison with 2-Aryl-3-oxosultams
Authors: Eilfeld Alexander , Hunger Jens , Sieler Joachim , Schulze Barbel
Published: February 2015

Stable 3-oxosultams were synthesized by oxidation of the 2-hetaryl-substituted isothiazolium salts. X-Ray crystal structure analyses of the sultams reveal the existence of strong and weak hydrogen bonds, which lead to different interaction combinations and solid state structures. While the bond lengths and angles in the isothiazol rings of the sultams are similar, the dihedral angles between the isothiazol rings and the hetaryl substituents are influenced by the position of the nitrogen atom in the pyridine ring and its substituents. The sultams form chain structures, dimeric head-to-tail structures or two-dimensional networks.
Reinvestigation of the Thiazole Synthesis with Ethyl 3-Amino-2- [5-aryl-1,3,4-oxadiazol-2(3H)-ylidene]-3-thioxopropanoates and Related Reactions
Authors: Paepke Nico , Reinke Helmut , Peseke Klaus , Vogel Christian
Published: February 2015

Treatment of the 1,3,4-oxadiazoles 3a and 3b with 3-chloropentane-2,4-dione gave the thiazoles 4a and 4b, respectively, which were methylated to furnish compounds 5a and 5b. The formation of 1,3,4-oxadiazoles using the 1,3-dithietane 1 as starting material, and the consecutive reactions mentioned above were transferred into sugar chemistry to provide the corresponding derivatives 6 - 9 in good yields. The reaction of 5a with benzyl amine, ethylene diamine and o-phenylene diamine afforded compounds 10, 11, and 12, respectively, which possess better stabilized push-pull systems than 5a. The structures of 3a, 4a, 5a, 10, 11, and 12 were compared with the previously proposed structures I - VI, respectively. The structures of compounds 1, 3b, and 11 were confirmed by X-ray diffraction studies.
Synthetic Routes to Core-fluorinated Perylene Bisimide Dyes and their Properties
Authors: Schmidt Rüdiger , Osswald Peter , Könemann Martin , Würthner Frank
Published: February 2015

Numerous core-fluorinated perylene bisimide (PBI) dyes with various substituents at the imide positions have been synthesized by different methods. Core-difluorinated PBIs 4a-f are obtained by imidization of difluoro-substituted perylene bisanhydride 1 with appropriate primary amines or, alternatively, by nucleophilic halogen exchange reactions (Halex process) of the corresponding dibromosubstituted PBIs 2a-d,f with potassium fluoride. Core-tetrafluorinated PBIs 5a-c could also be synthesized by halogen exchange reactions of the respective tetrachlorinated PBIs 3a-c. In particular, core-fluorinated perylene bisimide pigments 4h, 5h containing hydrogen atoms in the imide positions could be obtained for the first time by deprotection of α-methylbenzyl-substituted precursors. Compared with core-unsubstituted perylene bisimides, these fluorinated dyes display hypsochromically shifted absorption and fluorescence spectra, and they exhibit fluorescence quantum yields up to unity, enabling bright yellow emission. The electrochemical properties of these electron-poor perylene bisimides have been studied. Furthermore, the packing features of a tetrafluorinated PBI derivative in the solid state have been discussed.
On the Formation of Mauvein: Mechanistic Considerations and Preparative Results
Authors: Heichert Christoph , Hartmann Horst
Published: February 2015

The reaction of aniline (AH2) with an oxidizing agent in acidic solution gives rise to the formation of a mixture of products containing, besides a variety of oligoanilines named as Aniline Black or Polyaniline, Mauvein as a deeply purple phenazine derivative. Although this Mauvein synthesis was developed by W.H. Perkin more than 150 years ago and has opened the era of industrial dyestuff chemistry, the detailed mechanism of this reaction has remained rather unclear until today. The elucidation of the mechanism of the Mauvein formation as an oxidative coupling process of AH2 is hindered by the fact that several different types of coupling reactions occur simultaneously. Among them the C,N-coupling reaction is the most important one and responsible for the formation of Polyaniline and Mauvein. It gives rise to the formation of, e. g. 2 different aniline dimers, 7 trimers and more than 20 tetramers including Mauvein as one representative of these tetramers. In the present study, the oxidative coupling of a mixture of AH2 and 4-amino-4`-(N-anilino)-diphenylamine (TaH2) as one of the aniline trimers was studied in more detail. The reaction leads to the formation of Mauvein in satisfactory yields and, after some manipulations, widely free of byproducts. By using simple aniline derivatives as co-reagents in the oxidative coupling with TaH2, the reaction can be extended to the synthesis of different Mauvein derivatives most of which have been unknown to date.
One-dimensional Coordination Polymers of Cadmium Thiolates with 4,4'-Trimethylenebipyridine Ligands
Authors: Xua Chao , Wu Fang-Hui , Zhang Qian-Feng , Duan Taike
Published: February 2015

Hydrothermal reactions of Cd(SAr)2 with 4,4'-trimethylenebipyridine (tmdp) at 145 °C yielded new complexes, [Cd(SAr)2(tmdp)2]n (Ar = Ph, 1, C6H4Me-4, 2), which are one-dimensional wavelike coordination polymers with distorted tetrahedral CdN2S2 coordination environments. The thermal stability of the two complexes was studied by thermal gravimetric (TG) and differential thermal analyses (DTA).
Highest Connectivity in a Purely Inorganic 3D Compound Based on Paradodecatungstate-B Clusters: Synthesis and Magnetic Properties
Authors: Zhang Chun-Jing , Pang Hai-Jun , Chen Ya-Guang
Published: February 2015

A new paradodecatungstate-B compound, [{Co(H2O)4}4(H4W12O42)]·10H2O (1) of the polyoxometalate series has been synthesized and characterized by elemental analysis, IR and UV spectroscopy, TG analysis, and single-crystal X-ray diffraction. Compound 1 exhibits a unique 8- connected three-dimensional (3D) framework with a (42 · 820 · 126) topology. Moreover, 1 displays antiferromagnetic interactions in the 2 - 300 K temperature range, well reproduced by a simulation procedure.
Synthesis and Crystal Structure of a Sandwich-type Transition Metal Complex with Tungstobismutate and Triethanolamine
Authors: Xu Xiuhong , Zhang Ling , Zhang Yi , Qi Bin , Luo Fang
Published: February 2015

The sandwich-type complex Na(H2O)6(C6H16O3N)2[Na2(H2O)7(C6H16O3N)]2[(Na(H2O)2)3- (Cu(H2O))3(BiW9O33)2]・14H2O (1) (C6H16O3N+ = protonated triethanolamine) has been synthesized and structurally characterized by single-crystal X-ray diffraction, IR spectroscopy and TG analysis. The basic framework of 1 is built from a sandwich-type [(Na(H2O)2)3- (Cu(H2O))3(BiW9O33)2]9− anion, two [Na2(H2O)7(C6H16O3N)]3+ cations, a free Na(H2O)6
+ cation, and two free C6H16O3N+ units. In compound 1, the [(Na(H2O)2)3(Cu(H2O))3- (BiW9O33)2]9− anion links two bi-nuclear units [Na2(H2O)7(C6H16O3N)]3+ to form a [Na2- (H2O)7(C6H16O3N)]2[(Na(H2O)2)3(Cu(H2O))3(BiW9O33)2]3− cluster, and a new 3D supramolecular structure is further constructed by hydrogen bonding interactions among this cluster, the free Na(H2O)6
+ cation, and the free C6H16O3N+ cations. Crystal data: Cu3Na8Bi2W18C24H150O121N4, monoclinic, C2/c, a = 14.5668(13), b = 23.0405(13), c = 37.412(2) Å , β = 91.569(10)° , Z = 4.
Imidazolium Phenolates
Authors: Kuhn Norbert , Maichle-Mößmer Cäcilie , Steimann Manfred
Published: February 2015

1,3-Diisopropyl-4,5-dimethylimidazolium phenolate (4a), pentafluorophenolate (4b), and pentachlorophenolate (4c) are obtained from 2,3-dihydro-1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (2) and the corresponding phenols 3 as stable crystals in excellent yields. The crystal structure analyses of compounds 4 reveal the presence of ion pairs linked by almost linear C-H・・・O hydrogen bonds. With 4-hydroxypyridine (5), the carbene 2 gives 1,3-diisopropyl-4,5-dimethylimidazolium 4- pyridinolate (6) whose crystal structure analysis indicates the ions to be connected by a C-H・・・N bond.
A General Synthesis of 4-Arylaminoquinazoline-2-carbonitriles
Authors: El-Shaieb Kamal M. , Hopf Henning , Jones Peter G.
Published: February 2015

4-Arylaminoquinazoline-2-carbonitriles 5a - i were obtained by a one-step synthesis in moderate to good yield by reacting 2-aminoarylbenzimidamides 3a - i with tetracyanoethylene (TCNE, 4) in ethyl acetate at r. t. for 4 - 6 h. The structure of the selected benzimidamide 3c was determined by single crystal X-ray diffraction.
Synthesis of 2-(2-Aminophenyl)-4-arylquinazoline Derivatives by Reaction of 2-Aminoarylbenzimidamides with Isatoic Anhydride
Authors: El-Shaieb Kamal M. , Jones Peter G.
Published: February 2015

A series of 2-(2-aminophenyl)-4-arylquinazoline derivatives (5a - j), with various 4-substituents, have been synthesized by one-pot cyclization in 66 - 79% yield by heating 2-aminoarylbenzimidamides 3a - j with isatoic anhydride (4). The high yield and simplified workup procedure, in addition to the neutral reaction conditions, are the main advantages of our approach. The structure of the product 5e was further confirmed by single-crystal X-ray structure analysis
Regioselective N-Acetylation of 4-(2-Hydroxyphenyl)-2-phenyl-2,3- dihydro-1H-1,5-benzodiazepine Using Protection by an Intramolecular Hydrogen Bond
Authors: Escobar Carlos A. , Orellana-Vera Jorge , Vega Andrés , Sicker Dieter , Sieler Joachim
Published: February 2015

Since the amino and the hydroxyl groups of 4-(2-hydroxyphenyl)-2-phenyl-2,3-dihydro-1H-1,5- benzodiazepine can both act as nucleophiles, the introduction of both an N-acetyl and an O-acetyl group is expected when the compound is allowed to react with an excess of an electrophile such as acetic anhydride. An intramolecular hydrogen bond between OH and N-5 of the benzodiazepine has been used to obtain differentiation between the two possible sites of acetylation. Thus, this feature offers a preparatively utilizable protecting effect for the OH group and allows for a regioselective N-acetylation at ambient temperature. Both mono- and diacetylated compounds were prepared and characterized by crystal structure analysis
Fused Quinoline Heterocycles IX: First Example of a 3,4-Diamino-1H-pyrazolo[4,3-c]quinoline and a 3-Azido-1H-1,2,4,5,6,6a-hexaazabenzo[a]indacene
Authors: Mekheimer Ramadan Ahmed , Hameed Afaf Mohamed Abdel , Refaey Saeed Mohamed , Ibrahim Mohamed Ashry , Sadek Kamal Usef , Shah Anamik
Published: February 2015

4-Alkylamino-2-chloroquinoline-3-carbonitriles 4a - c react with NaN3 to give the corresponding tetrazolo[1,5-a]quinoline-4-carbonitriles 5a - c which are converted into 2-amino-quinoline-3-carbonitriles 8a - c by reaction with PPh3 via an iminophosphorane and subsequent hydrolysis. On the other hand, the new 3,4-diamino-1H-pyrazolo[4,3-c]quinoline (11) was prepared by fusion of the aminoquinolines 8a - c with hydrazine hydrate. Diazotization of 11 followed by reaction with NaN3 yielded the novel tetracyclic ring system 3-azido-1H-1,2,4,5,6,6a-hexaazabenzo[a]indacene (13)
Formation and Crystal Structure of 2,3,5-Triphenyltetrazolium Hexachlorophosphate and Dichlorophosphate(V), [TPT]+[PCl6]– and [TPT]+[PO2Cl2]–
Authors: Xie Tao , Brockner Wolfgang , Gjikaj Mimoza
Published: February 2015

2,3,5-Triphenyltetrazolium hexachlorophosphate, [C19H15N4]+[PCl6]−, [TPT]+[PCl6]− (1), and 2,3,5-triphenyltetrazolium dichlorophosphate(V), [C19H15N4]+[PO2Cl2]−, [TPT]+[PO2Cl2]− (2), were synthesized by reactions of anhydrous 2,3,5-triphenyltetrazolium chloride, [TPT]+Cl−, and 2,3,5-triphenyltetrazolium chloride monohydrate [TPT]+Cl− ・H2O, with PCl5 in dry acetonitrile, and their crystal structures were determined by single-crystal X-ray diffraction analysis. In the title compounds, the [TPT]+ cations show a face-to-face stacked orientation between the phenyl rings of neighboring molecules, which is caused by intermolecular π ・ ・ ・π interactions. The crystal structure of compound 1 consists of layers of 2,3,5-triphenyltetrazolium cations and hexachlorophosphate anions. In compound 2 the tetrahedral [PO2Cl2]− anions exhibit approximate C2v symmetry with P-O bond lengths from 1.454 to 1.463 Å and P-Cl bond lengths from 2.038 to 2.050 Å . The Raman spectrum of compound 1 was recorded, and the assignment of the [PCl6]− Raman modes is proposed.
Differential Pulse Voltammetric Studies of Some Mixed-ligand Co(III) Complexes in Aquo-Organic Solvent Media Possessing Different Hydrogen Bonding Properties
Authors: Sivaraj Kumarasamy , Elango Kuppanagounder P.
Published: February 2015

The electro-reduction of a series of Co(III) complexes of the type cis-β -[Co(trien)(4-R-Py)Cl]Cl2, where trien = triethylenetetramine and R = H, Me, Et, t-Bu, COMe, and CN, has been studied in propan-2-ol/water and 1,4-dioxane/water binary mixtures. The redox potential (E1/2) data were correlated with solvent and structural parameters with an aim to shed some light on the mechanism of these reactions. Correlation of E1/2 with macroscopic solvent parameters indicated that the reactivity is influenced by both specific and non-specific solute-solvent interactions. The reduction of Co(III) to Co(II) in these complexes was observed to become increasingly easier with an increase in the dipolarity/ polarizability of the medium as evidenced by the Kamlet-Taft correlation. The difference in the relative lenience of the reduction has been explained using the difference in H-bonding properties of the medium.
High-pressure Syntheses and Crystal Structures of Monoclinic B-Ho2O3 and Orthorhombic HoGaO3
Authors: Hering Stefanie A. , Huppertz Hubert
Published: February 2015

Monoclinic holmium sesquioxide B-Ho2O3 and orthorhombic holmium orthogallate HoGaO3 were synthesized in a Walker-type multianvil apparatus under high-pressure / high-temperature conditions of 11.5 GPa / 1250 °C and 7.5 GPa / 1250 °C, respectively. Both crystal structures could be determined by single-crystal X-ray diffraction data, collected at r. t. The monoclinic holmium oxide crystallizes in the space group C2/m (Z = 6) with the parameters a = 1394.7(3), b = 350.83(7), c = 865.6(2) pm, β = 100.23(3)°, R1 = 0.0517, wR2 = 0.1130 (all data), and the orthorhombic compound HoGaO3 in Pnma (Z = 4) with the parameters a = 553.0(2), b = 753.6(2), c = 525.4(2) pm, R1 = 0.0222, and wR2 = 0.0303 (all data).
Two New Supramolecular Assemblies Obtained by Reaction Between Saccharin and Long-chain Diamines
Authors: Castellano Eduardo E , Piro Oscar E. , Parajón-Costa Beatriz S. , Baran Enrique J.
Published: February 2015

The crystal structures of heptamethylenediammonium bis(saccharinate) monohydrate, [H3N - (CH2)7 -NH3](sac)2・H2O (1) and octamethylenediammonium bis(saccharinate) hemihydrate, [H3N- (CH2)8-NH3](sac)2・0.5H2O (2), were determined by single-crystal X-ray diffraction methods. Compound 1 crystallizes in the triclinic space group P1̄ with 2 molecules per unit cell, and 2 in the monoclinic space group P21/a with Z = 4. The saccharinate moiety is planar in both compounds presenting bonding characteristics comparable to those found in other saccharinate salts. The ionic crystals are further stabilized by an extensive H-bonding network, which links the anions and cations into an infinite three-dimensional supramolecular assembly. The FTIR spectra of the adducts are briefly discussed in comparison with those of the constituent molecules.
An Exploration of the Metal Oxide-assisted Decomposition and Rearrangement of N-Acyl-1,3-oxazolidin-2-ones Leading to 2-Aryl-2-oxazolines [1]
Authors: Deshpande Ankur A. , Gossagea Robert A. , Jackson Sarah M. , Quail J. Wilson , Sadowy Amber L. , Yadav Paras N.
Published: February 2015

An exploration into the utility of the thermally-induced (metal oxide-mediated) CO2 extrusion and subsequent rearrangement of N-acyl-1,3-oxazolidin-2-ones to form 2-aryl(alkyl)-2-oxazolines is described. The reaction is found to give moderate yields of the corresponding 2-oxazolines. Attempts to employ the above methodology to give enantiopure (R)- or (S)-2,5-diphenyl-2-oxazoline (the latter form being the natural product Oxytriphine) from enantiopure (and crystallographically characterised) (S)-N-benzoyl-5-phenyl-2-oxazolidinone led to the isolation of an essentially racemic product. These protocols are compared to other common methods used to form the oxazoline ring system and are placed into context with previous investigations of such ring forming reactions.
Reversible Regulation of a Benzamidine-catalyzed Aldol Reaction by CO2
Authors: Ilgen Florian , König Burkhard
Published: February 2015

The catalytic activity of benzamidine during an aldol reaction was reversibly switched on and off with CO2 as an orthogonal signal without affecting the converted substrate or products
Synthesis and Single Crystal X-Ray Structure of Bis[4-oxo-3- (2-ethoxycarbonylphenyl)-3,4-dihydroquinazolin-2-yl]disulfide
Authors: Rimaz Mehdi , Khalafy Jabbar , Tavana Khadijeh , Ślepokura Katarzyna , Lis Tadeusz , Souldozi Ali , Tofangchi Mahyari Amir , Shajari Nahid , Ramazani Ali
Published: February 2015

Diethyl 2,2´-thiocarbonyl-bis(azanediyl)dibenzoate was synthesized from the reaction of ethyl anthranilate with thiophosgene. Its treatment with sodium ethoxide in ethanol at room temperature gave ethyl 2-(4-oxo-2-thioxo-1,2-dihydroquinazolin-3(4H)-yl) benzoate, whereas in the presence of ethyl nitroacetate and under the same reaction conditions, the corresponding bis(quinazolin)disulfide was formed. Its structure was confirmed by IR, 1H and 13C NMR spectroscopy elemental analysis and single crystal X-ray structure determination.
Synthesis of a Silanol-substituted Proline Analog as Organocatalyst
Authors: Kracht Daniel , Saito Susumu , Fröhlich Roland , Wünsch Bernhard
Published: February 2015

A proline-derived silanol, was designed as a novel potential organocatalyst, and synthesized starting from the tetrazole 3. The central idea was the combination of an acidic (tetrazole) and a basic functionality (pyrrolidine) with a silanol moiety in the same molecule. The synthesis of 7 was performed in four reaction steps starting with the tetrazole 3. In the solid state (X-ray crystal structure analysis) the crucial functional groups show a favorable orientation. A chiral HPLC method and a chiral capillary electrophoresis method have been established for the investigation of the kinetic resolution of the racemic alcohols 9 and 11. Acetylation reactions of alcohols were not accelerated by the organocatalyst 7, and the produced ee values were rather low.
Partial Reduction of the N–O Functions of Partially Deprotonated Bis(hydroxylamine) Complexes
Authors: Bösing Patrick , Stammler Hans-Georg , Mitzel Norbert W.
Published: February 2015

The reduction of a partially deprotonated bishydroxylamine complex {(tBu2Ga)2[cyclo-ON(Me)(CH2)2- (Me)NO][HON(Me)(CH2)2(Me)(H)NO]} with a reagent composed of titanium tetrachloride and methyllithium leads to the reduction of one of the N-O groups to an amine function affording the salt {(tBu2Ga)[cyclo- ON(H)(Me)(CH2)2NHMe]}+ {tBu2GaCl2}−. This has been characterised by 1H and 13C NMR spectroscopy, by elemental analysis and by single crystal X-ray diffraction, showing the neutral amine/hydroxylamine ligand to be present in its tautomeric aminoxide form. The molecules form hexameric cyclic aggregates by N-H···Cl hydrogen bonds.
Synthesis and Crystal Structure of M([12]crown-4)2O3 · 1.5 NH3 with M = K, Rb
Authors: Nuss Hanne , Jansen Martin
Published: February 2015

The two new ozonide compounds K([12]crown-4)2O3 ・ 1.5 NH3 (1) and Rb([12]crown-4)2O3 ・ 1.5 NH3 (2) were synthesized from the binary alkali metal ozonides and [12]crown-4 in liquid ammonia. The air- and temperature-sensitive red, needle-shaped compounds crystallize isostructurally in the non-centrosymmetric space group Fdd2 (no. 43) with 16 formula units per unit cell. The lattice parameters are a = 26.917(8), b = 43.25(1), c = 7.823(2) Å, V = 9108(5) Å3; and a = 26.730(6), b = 44.70(1), c = 7.739(2) Å, V = 9245(4) Å3 for 1 and 2, respectively. The structure comprises rod-like [([M([12]crown-4)2(NH3)]O3)2(NH3)] supramolecular units, forming a fishbone pattern parallel to (001). The ozonide anions are separated from the metal cations and interact only weakly with two ammonia molecules via N-H・ ・ ・O hydrogen bonds
An Extension of Pnictide Oxide Chemistry – Salt Flux Synthesis and Structure of La5Cu4As4O4Cl2
Authors: Eul Matthias , Johrendt Dirk , Pöttgena Rainer
Published: February 2015

La5Cu4As4O4Cl2 was prepared from a cold-pressed pellet of lanthanum filings, ground arsenic, Cu2O and LaOCl in the ideal 3 : 4 : 2 : 2 ratio. The pellet was annealed in an evacuated silica tube at 1473 K for two days and then cooled down to room temperature. LaOCl was always observed as a by-product. La5Cu4As4O4Cl2 crystallizes with a new structure type: I4/mmm, a = 413.46(7), c = 4144(1) pm, wR2 = 0.0763, 328 F2 values, 26 parameters. The new quaternary arsenide oxide La3Cu4As4O2 with La3Cu4P4O2-type structure (I4/mmm) was obtained in polycrystalline form: a = 413.0(1), c = 2748.6(1) pm. The structure of La5Cu4As4O4Cl2 is an intergrowth of structural slabs of LaOCl (PbFCl type), ZrCuSiAs- and La3Cu4P4O2-related slabs. The copper atoms have tetrahedral arsenic coordination, and all oxygen atoms fill lanthanum tetrahedra. In the LaOCl slab we observe a van der Waals gap built up by the chloride anions. Half of the arsenic atoms within the La3Cu4P4O2-related slab form As2
4− dumb-bells at an As-As distance of 249 pm. Electronic band structure calculations reveal La5Cu4As4O4Cl2 as a strongly anisotropic hybride material, composed of covalently bonded metallic CuAs4/4 layers, sandwiched between ionic insulating oxide and chloride blocks
1,3,2-Diazaphospha-[3]ferrocenophanes. Molecular Structures and Multinuclear Magnetic Resonance Studies
Authors: Wrackmeyer Bernd , Klimkina Elena V. , Milius Wolfgang
Published: February 2015

2-Phenoxy-1,3,2-diazaphospha-[3]ferrocenophane and related derivatives (oxide, sulfide, selenide) were prepared, characterized in solution by multinuclear magnetic resonance methods (1D and 2D 1H, 13C, 15N and 31P NMR) and in the solid state by X-ray structural analysis. The conformation of the 2-phenoxy derivative differs from that of the 2-tert-butyl compound. For further comparison, 2-R- 2,3-dihydro-1H-1,3,2-diazaphospha-phenalene derivatives R = 'Bu, PhO were prepared and studied by the same NMR techniques. The molecular structure of a selenide was determined, and together with the NMR evidence, it was concluded that the conformation of these heterocycles is independent of the respective substituent at the phosphorus atom
Synthesis and Characterization of a Three-dimensional Coordination Polymer Based on Copper(II) Nitrate and a Tridentate Tetrazole Ligand
Authors: Hartdegen Vera , Klapötke Thomas M. , Sproll Stefan M.
Published: February 2015

Tris(2-(1H-tetrazol-1-yl)ethyl)amine (1) was synthesized as gas-generating agent and characterized by vibrational (IR) and NMR spectroscopy. The energetic properties were determined by bomb calorimetric measurements along with calculations using the EXPLO5 software. Tris(2-(1H-tetrazol- 1-yl)ethyl)amine (1) was used for further reactions with copper(II) nitrate to form a three-dimensional coordination polymer 3. Both compounds were characterized by single crystal X-ray diffraction. The thermal stability was determined by DSC measurements and the physical stability by BAMstandards. Tris(2-(1H-tetrazol-1-yl)ethyl)amine (1) proved to be suitable as gas-generating agent with sufficient physical and thermal stabilities. The low thermal stability of the copper complex 3 disqualifies it as potential colorant agent for pyrotechnical applications
Silicon(IV) Chelates of an (ONN')-Tridentate Pyrrole-2-Carbaldimine Ligand: Syntheses, Structures and UV/Vis Properties
Authors: Gerlach Daniela , Ehlers Andreas W. , Lammertsma Koop , Wagler Jörg
Published: February 2015

The tridentate (ONN_)-chelator properties of the pyrrole-2-(o-hydroxyphenyl)carbaldimine dianion (L2−) were explored for the neutral penta-coordinate diorganosilicon complexes LSiRR' (R,R' = Ph, Ph; Ph, Me; Ph, tBu) where the ligand L occupies the ax-eq-ax sites in a distorted trigonalbipyramidal arrangement arround the silicon atom, and for the neutral hexa-coordinate L2Si, that has a mer-coordination. Single-crystal X-ray diffraction analyses show an almost planar ligand backbone with a Si-N bond to the imine group that is shorter in hexa-coordinate L2Si than in pentacoordinate LSiRR'. In sharp contrast to the almost colorless neutral ligand LH2, both complexes show pronounced UV/Vis absorptions in the red-brown region that originate from HOMO- LUMO and HOMO-1 -LUMO transitions, and that are due to intra-ligand π-π∗ transitions from the N-ooxyphenylimine towards the imine moiety
Thienopyridone Antibacterials V [1]. Synthesis of Some N(7)-Azacyclohexyl-4-oxothieno[2,3-b]pyridine-5-carboxylic Acids and Related Congeners
Authors: Al-Jaber Hala I. , El-Abadelah Mustafa M. , Sabri Salim S. , Al-Tel Taleb H. , Voelter Wolfgang
Published: February 2015

A series of N(7)-azacyclohexyl-4-oxo-4,7-dihydrothieno[2,3-b]-pyridine-5-carboxylic acids 9a - c, related congeners 9d - g and their methyl esters 8a - g were prepared by cyclization of the respective 2-[(2,5-dichlorothien-3-yl)carbonyl]-3-[(N(7)-azacyclyl/acyclic)amino]acrylates 7a - g. The latter intermediates are accessible from methyl 2-[(2,5-dichlorothien-3-yl)carbonyl]-3-ethoxyacrylate (6). Of the present series, the 7-(N,N-dimethylamino) derivative 9d exhibited good activity, especially against Klebsiella pneumoniae and Salmonella paratyphi A (MIC = 0.5 and 1.0 μgmL−1, respectively).
A Triple Newman-Kwart Rearrangement at a Fully Substituted Benzene Ring
Authors: Theil Hubert , Fröhlich Roland , Glaser Thorsten
Published: February 2015

The Newman-Kwart rearrangement of O-thiocarbamates to S-thiocarbamates is a versatile method for the conversion of phenols into thiophenols. The triple rearrangement of the O-trithiocarbamate 2,4,6-triacetyl-1,3,5-tri-(dimethylthiocarbamoyloxy)benzene (2) to the S-trithiocarbamate 2,4,6- triacetyl-1,3,5-tri-(dimethylthiocarbamoylthio)benzene (3) is performed, which is unprecendented for fully substituted benzene rings. The synthesis and characterization of the O-trithiocarbamate 2 and the S-trithiocarbamate 3 including the single-crystal X-ray structure analysis of compound 3 are presented
A First Experimental Electron Density Study on a C70 Fullerene: (C70C2F5)10
Authors: Kalinowski Roman , Weber Manuela , Troyanov Sergey I. , Paulmann Carsten , Luger Peter
Published: February 2015

The electron density of the C70 fullerene C70(C2F5)10 was determined from a high-resolution X-ray data set measured with synchrotron radiation (beamline F1 of Hasylab/DESY, Germany) at a temperature of 100 K. With 140 atoms in the asymmetric unit this fullerene belongs to the largest problems examined until now by electron density methods. Using the QTAIM formalism quantitative bond topological and atomic properties have been derived and compared with the results of theoretical calculations on the title compound and on free C70
Crystal Structure of Silver Chromate Silicate, Ag6(CrO4)(SiO4)
Authors: Klein Wilhelm , Jansen Martin
Published: February 2015

The new silver chromate silicate Ag6(CrO4)(SiO4) has been obtained from Ag2O and SiO2 by solid-state reaction at elevated temperature and oxygen pressure in stainless-steel autoclaves. It crystallizes in space group I41/amd (no. 141) with a = 7.256(2), c = 17.584(6) Å, V = 925.9(5) Å3, Z = 4; the structure refinement was based on 314 independent reflections and resulted in R1 = 0.0488, wR2 = 0.0987 (I ≥ 2σ (I)). The crystal structure consists of isolated CrO4 and SiO4 tetrahedra which are linked by Ag cations. The two different types of Ag atoms are in a square-planar fourfold, and linear twofold coordination by oxygen atoms, respectively. The linearly coordinated Ag atoms combined with the SiO4 tetrahedra form a three-dimensional 3
∞[Ag4SiO4] framework, accommodating the CrO4 tetrahedra and the remaining Ag atoms in the voids. The CrO4 tetrahedron shows slightly enlarged displacement parameters indicating somewhat enhanced librational motion of the rigid body
On the Magnetic and Mössbauer Spectroscopic Characterization of EuPd2Sb2
Authors: Schellenberg Inga , Eul Matthias , Pöttgen Rainer
Published: February 2015

The CaBe2Ge2-type antimonide EuPd2Sb2 (P4/nmm, a = 462.43(7), c = 1056.1(2) pm) was synthesized by induction melting of the elements in a sealed tantalum tube. Temperature-dependent magnetic susceptibility measurements have revealed Curie-Weiss behavior with an experimental magnetic moment of 7.93(1) μB/Eu atom, indicating stable divalent europium. EuPd2Sb2 orders antiferromagnetically at TN = 4.5(2) K as is also evident from almost full hyperfine field splitting (Bh = 19.5 T) in the 151Eu Mössbauer spectrum at 4.2 K
Mechano-thermally Activated Solid-state Synthesis of Li4Ti5O12 Spinel from Li2CO3-TiO2 Mixtures
Authors: Berbenni Vittorio , Milanese Chiara , Bruni Giovanna , Marini Amedeo
Published: February 2015

Simultaneous TG/DSC measurements performed on mixtures 2Li2CO3-5TiO2 (anatase) subjected to high-energy milling showed that both the temperature and the enthalpy of Li2CO3 decomposition are much lower than in the case of TG/DSC runs performed on a sample of a physical mixture. On the basis of the thermoanalytical evidence a solid-state synthesis of the spinel compound Li4Ti5O12 has been proposed that combines mechanical (by high-energy milling) and thermal activation (8 h annealing at 973 K): the obtained compound shows a lattice constant in very good agreement with that expected for the pure phase Li1+xTi2−xO4 (x = 0.333). The molar heat capacity of Li4Ti5O12 has been determined in the temperature range 323 - 633 K by quasi-isothermal Modulated Differential Scanning Calorimetry (MDSC). The specific surface area of Li4Ti5O12 has been determined by gas adsorption
A Two-dimensional Rare Earth Metal-Organic Polymer {[Pr2(csph)2(H2O)4]·6H2O}n with 3-Carboxylate-4-sulfonatophenolate (csph) Ligands
Authors: Wu Gang , Wang Zhu-Mei , Ge Xiu-Tao , Wang Xiao-Ling , Zhang Qian-Feng
Published: February 2015

A two-dimensional rare earth metal-organic polymer {[Pr2(csph)2(H2O)4]· 6H2O}n (1) with 3- carboxylate-4-sulfonato-phenolate (csph) ligands was obtained by hydrothermal synthesis and characterized by elemental analysis and IR spectroscopy, and also by single-crystal X-ray diffraction. The crystal is orthorhombic, space group Pbcn with a = 15.9113(6), b = 9.3563(4), c = 16.0497(6) Å , Z = 4, and V = 2240.46(16) Å3. The praseodymium atom is coordinated to eight oxygen atoms from the csph3− ligands and two water molecules to form a distorted dodecahedron. The csph3− ligands involved in forming a two-dimensional framework are all multiply bridging via the sulfonate (μ2, η2) and the carboxylate groups (μ3, η2:η1). The thermal stability of complex 1 was studied by thermogravimetric analysis (TGA), and the photoluminescence properties of complex 1 were also investigated
New Guanidinium-based Room-temperature Ionic Liquids. Substituent and Anion Effect on Density and Solubility in Water
Authors: Bogdanov Milen G. , Petkova Desislava , Hristeva Stanimira , Svinyarov Ivan , Kantlehner Willi
Published: February 2015

In order to examine the influence of the alkyl chain length on some physical properties of guanidinium salts, the synthesis of a homologous series of new N″-n-alkylsubstituted N,N-diethyl-N′ ,N′- di-n-propyl-N″-n-hexyl guanidinium ionic liquids (gILs), containing chloride (Cl), tetrafluoroborate (BF4), acesulfamate (Ace), saccharinate (Sac), and tosylate (Tos) as anions, is reported. Cn-gILAce, Cn-gILSac, and Cn-gILBF4 were obtained by ion exchange reaction of the corresponding hexasubstituted guanidinium chlorides (Cn-gCl, n = 3, 4, 6, 8, 10), which were synthesized by a quaternization reaction of the pentaalkyl-substituted guanidine 3 and the corresponding alkylchloride in DMF. The tosylates gILs Cn-gTos (n = 1, 2, 4, 6, 8, 10) were synthesized by alkylation of 3 with the corresponding alkyltosylates. Some physical properties, such as solubility in water and organic solvents, refractive index and density, are considered as a function of the length of the n-alkyl substituent R and the nature of the anion
Copper-catalyzed Synthesis and Antimicrobial Activity of Disubstituted 1,2,3-Triazoles Starting from 1-Propargyluracils and Ethyl (4-Azido- 1,2,3-trihydroxybutyl)furan-3-carboxylate
Authors: El-Sayed Wael A. , Abdel-Rahman Adel A.-H.
Published: February 2015

1,3-Dipolar cycloaddition reactions of 1-propargyluracils 2a - h with the azido derivative 3 afforded the corresponding 1,2,3-triazoles 4a - h. Hydrazinolysis of the esters 4a - h gave the corresponding acid hydrazides 5a - h. Reaction of 5a - h with carbon disulfide in ethanol afforded 6a - h. The antimicrobial activity of compounds 4 - 6 was determined
Two Novel Norlignan Derivatives from Curculigo breviscapa
Authors: Li Ning , Zhu Cui-Cui , Wang Kai-Jin , Hu Jiang-Miao
Published: February 2015

Two novel skeleton-rearranged norlignans, breviscaside A (1) and breviscapin B (2), have been isolated from the rhizomes of Curculigo breviscapa. Their structures were established on the basis of spectroscopic techniques, especially the 2D NMR spectral analysis
New Dibenzocyclooctadiene Lignans from Schisandra sphenanthera and Their Proinflammatory Cytokine Inhibitory Activities
Authors: Ren Rong , Ci Xin-Xin , Li Hai-Zhou , Luo Guo-Jun , Li Rong-Tao , Deng Xu-Ming
Published: February 2015

Investigation of the fruits of Schisandra sphenanthera led to the isolation of two new dibenzocyclooctadiene lignans, methylgomisin O (1) and chloromethyl schisantherin B (2), together with twelve known lignans (3 - 14). Their structures were elucidated by using extensive spectroscopic techniques including 1D and 2D NMR spectra. Compound 2 was identified as a cyclooctadiene moiety substituted with a chloromethyl group, which is rarely found in natural products, especially in terrestrial higher plants. Among these isolates, compounds 1 and 7 exhibited considerable inhibitory activity against tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) production, and did not display any cellular toxicity against RAW264.7 cells.
Thermische Isomerisierung eines Silenketazins zum Diazasilacyclopenten: Experimentelle und theoretische Untersuchungen
Authors: Görth Martin , Abraham Sascha , Schmat Stefan , Ott Holger , Stalke Dietmar , Klingebiel Uwe
Published: February 2015

Lithium-tert-butylmethylhydrazonide II, Me3C(Me)C=N-NHLi, reacts with F2Si[N(CHMe2)2]2 to give Me3C(Me)C=N-NH-SiF[N(CHMe2)2]2 1. The lithium salt of 1, Me3 C(Me)C=N- N(Li)SiF[N(CHMe2)2]2, 1a, prepared in the reaction of 1 with n-C4H9Li, is substituted with F2BN(SiMe3)2 forming Me3C(Me)C=N-NBFN(SiMe3)2SiF[N(CHMe2)2]2, 2. Experiments to synthesise the silaketazine, Me3C(Me)C=N-N=Si[N(CHMe2)2], III, via LiF-elimination from 1a lead to the intramolecular formation of an N-functional 1,2-diaza-3-silacyclopentene, H2C-C(CMe3)=N- NHSi[N(CHMe2)2]2, 3, which is a structural isomer of III. The NH unit of 3 can be lithiated with n-C4H9Li. The lithium salt reacts with F2BN(SiMe3)2 forming the substituted ring compound 4. The rearrangement of the silaketazine III to the ring compound 3 is described by density functional calculations predicting a three-step reaction mechanism correlated with the experimental data. The structures of 3 and 4 are discussed in detail.
Supramolecular Assembly through the Highest Connectivity of a Keggin Polyoxometalate
Authors: Sha Jing-Quan , Liu Hai-Yan , Peng Jun , Wang Cheng , Lv Yu-Guang , Zhang Peng-Peng
Published: February 2015

A novel supramolecular compound based on the Keggin polyoxometalate (Hpipz)3[PMo12O40](1) (pipz = piperazine) has been synthesized and characterized. X-Ray diffraction analysis reveals that the Keggin polyanion uses all of its surface oxygen atoms (36) to attract eighteen pipz units at its periphery. This represents the highest connectivity of a Keggin polyoxoanion. The electrochemical behavior of a CPE modified with 1 (1-CPE) has been studied.
Synthesis and Crystal Structure of the Novel Three-dimensional Vanadium Coordination Compound Potassium Oxo-bis(hydroxylamido)malonatovanadate(V)
Authors: Zhang Qi-Ying , Zhang Heng-Qiang , Kong Ai-Guo , Yang Qian , Shan Yong-Kui
Published: February 2015

In the crystal structure of the title complex, K2[(VO)2(NH2O)4(C3H2O4)2] ・ 3H2O, the V(V) centre is bound to a chelating malonate ligand, two bidentate hydroxylamido ligands and one oxo ligand, defining a pentagonal bipyramidal coordination (VO5N2). The potassium cations are found to adopt two types of coordination geometry with the malonate ligand, the bidentate hydroxylamido ligand and water molecules: the first one is hepta-coordinate in an irregular K(1)O7 polyhedron, and the second one is octa-coordinate in an irregular K(2)O8 polyhedron. The K(1)O7/K(2)O8 and VO5N2 polyhedra are closely linked by sharing faces to form K-V dinuclear units KVO9N2 and KVO10N2, respectively. The two close-packed units, KVO9N2 and KVO10N2, are connected by sharing edges to generate a tetrameric unit K2V2O17N4. Each of these units is joined to four neighbouring units by sharing corners, providing further propagation into a two-dimensional layer. Adjacent layers are connected via the carboxylic oxygen atoms of the malonate units to give a three-dimensional framework in the crystals.
Synthesis and Structural Characterization of a New Two-dimensional Organic-Inorganic Hybrid Molybdoarsenate: [Cu(en)2]2[(CuO6)Mo6O18(As3O3)2]
Authors: Wu Qiang , Han Qiuxia , Chen Lijun , Ma Pengtao , Niu Jingyang
Published: February 2015

A new organic-inorganic hybrid molybdoarsenate constructed from a unit with two (As3O3) rings capping Anderson-type moieties, [Cu(en)2]2[(CuO6)Mo6O18(As3O3)2] (1) (en = ethylenediamine), has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction and thermogravimetric analysis. The compound crystallizes monoclinically, space group P21/c, with unit cell dimensions a = 9.1541(7), b = 19.6348(14), c = 14.5205(8) Å ,β = 129.082(3)◦,V = 364.20(4) Å3, Z = 2, T = 296(2) K. Complex 1 represents the first example of a 2D network of a POM polymer where [(CuO6)Mo6O18(As3O3)2]4− building blocks are connected by complex fragments {Cu(en)2}2+.
Microwave-assisted Conversion of Carbohydrates into 5-Hydroxymethylfurfural Catalyzed by ZnCl2
Authors: Zheng Baohui , Fang Zhijie , Cheng Jie , Jiang Yuhua
Published: February 2015

A convenient system for producing 5-hydroxymethylfurfural (HMF) through dehydration of carbohydrates by microwave heating in the presence of ZnCl2 was studied. The use of ZnCl2 gave higher selectivity than other metal salts in the conversion of glucose. With ZnCl2 as catalyst, sucrose could be utilized effectively. Under the conditions of microwave irradiation (300 W, 8 min), HMF yields were 54.6, 55.1, and 80.6% from glucose, fructose and sucrose, whereas upon conventional oil bath heating (0.11 gmL−1 sugar solution, weight ratio of ZnCl2 to substrate = 1 : 4, 189 °C, 60 min) HMF yields from glucose, fructose and sucrose were only up to 37.7, 42.7, and 57.7%, respectively.
Reactions of 3,5-Dimethyl-1,2,4,3,5-trithiadiborolane with Secondary Amines: Formation of Diorganylamino(sulfhydryl)boranes
Authors: Nöth Heinrich , Taeger Tilman
Published: February 2015

The 1 : 1 reaction of 3,5-dimethyl-1,2,4,3,5-trithiadiborolane, 3, with dimethylamine in diethyl ether yielded a mixture of compounds from which only MeB(NMe2)SH, 7, could be separated. In the 1:2 reaction, insoluble Me2NH(MeB(S2)2BMe)HNMe2, 10, could be isolated besides 7 and small amounts of MeB(NMe2)2. In the presence of NMe3 the bis(methyl-dimethylamino-boryl)sulfide, 7 was obtained in good yield. Replacement of HNMe2 by N-methylaniline or piperidine led to the corresponding amino(methyl)sulfhydrido boranes R2N(MeB)SH in moderate yields. tBuNH(MeB)SH results in 61% yield from the treatment of tBu2B2S3 with tBuNH2 in a 1 : 1 ratio.