bluuebunny/crossref_metadata_2025 huggingface dataset:
Intercrossed Carbon Nanorings with Pure Surface States as Low‐Cost and Environment‐Friendly Phosphors for White‐Light‐Emitting Diodes
Authors: Li Xiaoming , Liu Yanli , Song Xiufeng , Wang Hao , Gu Haoshuang , Zeng Haibo
Published: September 2014

As an important energy‐saving technique, white‐light‐emitting diodes (W‐LEDs) have been seeking for low‐cost and environment‐friendly substitutes for rare‐earth‐based expensive phosphors or Pd2+/Cd2+‐based toxic quantum dots (QDs). In this work, precursors and chemical processes were elaborately designed to synthesize intercrossed carbon nanorings (IC‐CNRs) with relatively pure hydroxy surface states for the first time, which enable them to overcome the aggregation‐induced quenching (AIQ) effect, and to emit stable yellow‐orange luminescence in both colloidal and solid states. As a direct benefit of such scarce solid luminescence from carbon nanomaterials, W‐LEDs with color coordinate at (0.28, 0.27), which is close to pure white light (0.33, 0.33), were achieved through using these low‐temperature‐synthesized and toxic ion‐free IC‐CNRs as solid phosphors on blue LED chips. This work demonstrates that the design of surface states plays a crucial role in exploring new functions of fluorescent carbon nanomaterials.
Origin and Location of Electrons and Protons during the Formation of Intermetalloid Clusters [Sm@Ga3−xH3−2xBi10+x]3− (x=0, 1)
Authors: Weinert Bastian , Müller Fabian , Harms Klaus , Clérac Rodolphe , Dehnen Stefanie
Published: September 2014

Reaction of [GaBi3]2− with [Sm(C5Me4H)3] yielded the first protonated ternary intermetalloid clusters [Sm@Ga3−xH3−2xBi10+x]3− (1; x=0,1). The presence of the GaH bonds and the transfer of electrons and protons during the formation of 1 were elucidated by a combination of experimental and quantum chemical methods, thereby rationalizing the role of the solvent ethane‐1,2‐diamine as a Brønsted acid. As an organic by‐product, we observed the previously unknown octamethylfulvene (2) upon CC coupling of (C5Me4H)−.
Copper‐Catalyzed Coupling of Triaryl‐ and Trialkylindium Reagents with Aryl Iodides and Bromides through Consecutive Transmetalations
Authors: Thapa Surendra , Gurung Santosh K. , Dickie Diane A. , Giri Ramesh
Published: September 2014

An efficient copper(I)‐catalyzed coupling of triaryl and trialkylindium reagents with aryl iodides and bromides is reported. The reaction proceeds at low catalyst loadings (2 mol %) and generally only requires 0.33 equivalents of the triorganoindium reagent with respect to the aryl halide as all three organic nucleophilic moieties of the reagent are transferred to the products through consecutive transmetalations. The reaction tolerates a variety of functional groups and sterically hindered substrates. Furthermore, preliminary mechanistic studies that entailed the synthesis and characterization of potential reaction intermediates offered a glimpse of the elementary steps that constitute the catalytic cycle.
Cationic polystyrene spheres for removal of anionic contaminants in white water of papermaking
Authors: Xiao He , He Beihai , Qian Liying , Li Junrong
Published: September 2014

In a paper mill's water circuit, normal runnability of the paper machine is often disturbed due to the buildup of dissolved and colloidal substances (DCS). Contaminant adsorption on a solid adsorbent in a fluidized bed reactor has been applied for white water treatment. In the present study, polystyrene (PS) spheres were firstly acylated by acryloyl chloride, then poly(methacryloxyethyltrimethyl ammonium chloride) (PMAC) was grafted onto the acylated PS spheres, induced by surface‐initiated free‐radical polymerization. Fourier transform infrared spectroscopy, thermal gravimetric analysis, and scanning electron microscopy were used to characterize the changes of PS spheres in chemical structures and surface morphology. The results showed that acylated PS spheres could be easily grafted with PMAC in 53.83% weight increase. Polyelectrolyte loading of PS spheres reached up to 1.72 mmol/g. The resulted cationic modified PS spheres could effectively decrease the cationic demand in white water and it still maintained high performance after operating repeatedly for 10 batches. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 10.1002/app.41379.
Study on the preparation of PU/HBP‐NH2 blend film and its properties
Authors: Longfang Ren , Na Wang , Xuechuan Wang
Published: September 2014

The blend films of polyurethane (PU) and amino‐terminal hyperbranched polymers (HBP‐NH2) were prepared successfully by mixing HBP‐NH2 solution and PU. The rate of moisture absorption and mechanical properties were determined. The results showed that the rates of moisture absorption and vapor permeability were improved from 0.34% to 7.51% and from 161 gm−2 d−1 to 879 gm−2 d−1, respectively. The addition of HBP‐NH2 is helpful to improve the hygiene properties of PU films. Then, the structures of the blend films were characterized by IR, XRD, TG, and SEM at the same time. The results indicated that HBP‐NH2 and PU had hydrogen‐bond interaction and a certain phase separation. The blend films had good heat stability. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41383.
An Amphiphilic Selenide Catalyst Behaves Like a Hybrid Mimic of Protein Disulfide Isomerase and Glutathione Peroxidase 7
Authors: Arai Kenta , Moriai Kenji , Ogawa Akinobu , Iwaoka Michio
Published: September 2014

Protein disulfide isomerase (PDI) and glutathione peroxidase 7 (GPx7) cooperatively promote the oxidative folding of disulfide (SS)‐containing proteins in endoplasmic reticulum by recognizing the nascent proteins to convert them into the native folds by means of SS formation and SS isomerization and by catalyzing reoxidation of reduced PDI with H2O2, respectively. In this study, new amphiphilic selenides with a long‐chain alkyl group were designed as hybrid mimics of PDI and GPx7 and were applied to the refolding of reduced hen egg‐white lysozyme (HEL‐R). Competitive SS formation at pH 4 using HEL‐R and glutathione (GSH) in the presence of the selenide catalyst and H2O2 showed that the amphiphilic selenides can preferentially catalyze SS formation of HEL‐R, probably on account of hydrophobic interactions between the protein and the catalyst. In contrast, simple water‐soluble selenides did not exhibit such behavior. In addition, when the pH of the solution was adjusted to 8.5 after the SS formation, surviving GSH promoted the SS isomerization of misfolded HEL to recover the native SS linkages. Thus, the amphiphilic selenides designed here could mimic the function of the PDI‐GPx7 system. The combination of a water‐soluble selenide and a long‐chain alkyl group would be a useful motif in designing medicines for both protein misfolding diseases and antioxidant therapy.
Large Magnetocaloric Effect in a Dense and Stable Inorganic–Organic Hybrid Cobridged by In Situ Generated Sulfate and Oxalate
Authors: Han Song‐De , Miao Xiao‐Hong , Liu Sui‐Jun , Bu Xian‐He
Published: September 2014

A dense and stable inorganic‐organic hybrid with distorted cubic [Gd4O4] units as building blocks bridged by in situ generated sulfate and oxalate was synthesized. Magnetic measurements indicate that the title complex features a −ΔSmmax=51.49 J kg−1 K−1, which is among the highest values reported so far.
4‐Channel Sliding Mode Control of Teleoperation Systems with Disturbances
Authors: Liu Xia , Dong Xiucheng
Published: September 2014

Sliding mode control can effectively account for the disturbances of a system. Among the different teleoperation architectures, 4‐channel architecture is the most successful for fulfilling transparency. In this paper, two sliding mode controllers are designed for nonlinear master and slave with external disturbances and are incorporated into a 4‐channel structure to achieve transparency. To this end, each of the controllers consists of a sliding mode position feedback law, a force feedback law, and two supplementary terms regarding gravity and contact force compensation. Stability and transparency of the overall system is studied via a Lyapunov function analysis. Simulations compared with the conventional adaptive control on teleoperation systems demonstrate the effectiveness of the proposed scheme.
Comparative proteomic analysis of antagonistic Bacillus amyloliquefaciens Q‐426 cultivated under different pH conditions
Authors: Zhao Jing , Zhao Pengchao , Quan Chunshan , Jin Liming , Zheng Wei , Fan Shengdi
Published: September 2014

Bacillus amyloliquefaciens Q‐426 produces lipopeptide compounds with antifungal activities. Initial pH value has a significant influence on the production of lipopeptide compounds. The correlation between pH and intrinsic mechanism of lipopeptide production was rarely discussed. In this research, comparative proteomics, using two‐dimensional gel electrophoresis and mass spectrometry, was applied to identify B. amyloliquefaciens Q‐426 intracellular proteins differentially expressed under initial pH 5.0 and 7.3. A total of 24 differential spots (eight downregulated and 16 upregulated) under pH 5.0 were identified. Certain proteins were involved in the regulation of bacillomycin and fengycin production by B. amyloliquefaciens Q‐426. These proteins include four induced proteins related to stress response: Thiamine pyrophosphate‐dependent acetoin dehydrogenase, butanediol dehydrogenase, two ABC‐type oligopeptide transport system proteins, and two‐component response regulator DegU and chorismate mutase PheB. These results indicate intrinsic differences of antagonistic B. amyloliquefaciens Q‐426 under different pH conditions.
Experience and the ever‐changing brain: What the transcriptome can reveal
Authors: Rubin Todd G. , Gray Jason D. , McEwen Bruce S.
Published: September 2014

The brain is an ever‐changing organ that encodes memories and directs behavior. Neuroanatomical studies have revealed structural plasticity of neural architecture, and advances in gene expression technology and epigenetics have demonstrated new mechanisms underlying the brain's dynamic nature. Stressful experiences challenge the plasticity of the brain, and prolonged exposure to environmental stress redefines the normative transcriptional profile of both neurons and glia, and can lead to the onset of mental illness. A more thorough understanding of normal and abnormal gene expression is needed to define the diseased brain and improve current treatments for psychiatric disorders. The efforts to describe gene expression networks have been bolstered by microarray and RNA‐sequencing technologies. The heterogeneity of neural cell populations and their unique microenvironments, coupled with broad ranging interconnectivity, makes resolving this complexity exceedingly challenging and requires the combined efforts of single cell and systems level expression profiling to identify targets for therapeutic intervention.
ATP puts the brake on DNA double‐strand break repair
Authors: Hopfner Karl‐Peter
Published: September 2014

DNA double‐strand breaks (DSBs) are one of the most deleterious forms of DNA damage and can result in cell inviability or chromosomal aberrations. The Mre11‐Rad50‐Nbs1 (MRN) ATPase‐nuclease complex is a central player in the cellular response to DSBs and is implicated in the sensing and nucleolytic processing of DSBs, as well as in DSB signaling by activating the cell cycle checkpoint kinase ATM. ATP binding to Rad50 switches MRN from an open state with exposed Mre11 nuclease sites to a closed state with partially buried nuclease sites. The functional meaning of this switch remained unclear. A new study shows that ATP binding to Rad50 promotes DSB recognition, tethering, and ATM activation, while ATP hydrolysis opens the nuclease active sites to promote processing of DSBs. MRN thus emerges as functional switch that may coordinate the temporal transition from signaling to processing of DSBs.
Forces shaping the antibiotic resistome
Authors: Perry Julie A. , Wright Gerard D.
Published: September 2014

Antibiotic resistance has become a problem of global scale. Resistance arises through mutation or through the acquisition of resistance gene(s) from other bacteria in a process called horizontal gene transfer (HGT). While HGT is recognized as an important factor in the dissemination of resistance genes in clinical pathogens, its role in the environment has been called into question by a recent study published in Nature. The authors found little evidence of HGT in soil using a culture‐independent functional metagenomics approach, which is in contrast to previous work from the same lab showing HGT between the environment and human microbiome. While surprising at face value, these results may be explained by the lack of selective pressure in the environment studied. Importantly, this work suggests the need for careful monitoring of environmental antibiotic pollution and stringent antibiotic stewardship in the fight against resistance.
Simultaneous determination of desloratadine and montelukast sodium using second‐derivative synchronous fluorescence spectrometry enhanced by an organized medium with applications to tablets and human plasma
Authors: Ibrahim F. A. , El‐Enany N. , El‐Shaheny R. N. , Mikhail I. E.
Published: September 2014

A rapid, simple, and sensitive second‐derivative synchronous fluorimetric method has been developed and validated for the simultaneous analysis of a binary mixture of desloratadine (DSL) and montelukast sodium (MKT) in their co‐formulated tablets. The method is based on measurement of the synchronous fluorescence intensities of the two drugs in McIlvaine's buffer, pH 2.3, in the presence of carboxy methyl cellulose sodium (CMC) as a fluorescence enhancer at a constant wavelength difference (Δλ) of 160 nm. The presence of CMC enhanced the synchronous fluorescence intensity of DSL by 216% and that of MKT by 28%. A linear dependence of the concentration on the amplitude of the second derivative synchronous fluorescence spectra was achieved over the ranges of 0.10–2.00 and 0.20–2.00 µg/mL with limits of detection of 0.02 and 0.03, and limits of quantification of 0.05 and 0.10 µg/mL for DSL and MKT, respectively. The proposed method was successfully applied for the determination of the studied compounds in laboratory‐prepared mixtures and tablets. The results were in good agreement with those obtained with the comparison method. The high sensitivity attained by the proposed method allowed the determination of MKT in spiked human plasma with average % recovery of 100.11 ± 2.44 (n = 3). Copyright © 2014 John Wiley & Sons, Ltd.
Bioproduction of highly charged designer peptide surfactants via a chemically cleavable coiled‐coil heteroconcatemer
Authors: Fletcher Nicholas L. , Paquet Nicolas , Dickinson Ellyce L. , Dexter Annette F.
Published: September 2014

Designer peptides have recently attracted attention as self‐assembling fibrils, hydrogelators and green surfactants with the potential for sustainable bioproduction. Carboxylate‐rich peptides in particular have shown potential as salt‐resistant emulsifiers; however the expression of highly charged peptides of this kind remains a challenge. To achieve expression of a strongly anionic helical surfactant peptide, we paired the peptide with a cationic helical partner in a coiled‐coil miniprotein and optimized the polypeptide sequence for net charge, hydropathy and predicted protease resistance (via the Guruprasad instability index). Our design permitted expression of a soluble concatemer that accumulates to high levels (22% of total protein) in E. coli. The concatemer showed high stability to heat and proteases, allowing isolation by simple heat and pH precipitation steps that yield concatemer at 133 mg per gram of dry cell weight and >99% purity. Aspartate‐proline sites were included in the concatemer to allow cleavage with heat and acid to give monomeric peptides. We characterized the acid cleavage pathway of the concatemer by coupled liquid chromatography‐mass spectrometry and modeled the kinetic pathways involved. The outcome represents the first detailed kinetic characterization of protein cleavage at aspartate‐proline sites, and reveals unexpected cleavage preferences, such as favored cleavage at the C‐termini of peptide helices. Chemical denaturation of the concatemer showed an extremely high thermodynamic stability of 38.9 kcal mol−1, with cleavage decreasing the stability of the coiled coil to 32.8 kcal mol−1. We determined an interfacial pressure of 29 mN m−1 for both intact and cleaved concatemer at the air‐water interface, although adsorption was slightly more rapid for the cleaved peptides. The cleaved peptides could be used to prepare heat‐stable emulsions with droplet sizes in the nanometer range. Biotechnol. Bioeng. 2015;112: 242–251. © 2014 Wiley Periodicals, Inc.
Development and validation of an LC‐APCI‐MS/MS method for the determination of phenethyl isothiocyanate in human plasma
Authors: Zheng Li. , Zheng Feng
Published: September 2014

Phenethyl isothiocyanate (PEITC) is a promising chemopreventive agent present in cruciferous vegetables. This paper describes the development of a method for the determination of PEITC in human plasma by liquid chromatography/tandem mass spectrometry (LC‐MS/MS). Atmospheric‐pressure chemical ionization was found more suitable for ionization of PEITC than electrospray ionization. Because of the lability of PEITC, a combination of low temperature and acidification was applied to minimize the degradation during the sample collection and preparation procedure. A simple protein precipitation with acetonitrile was used for the preparation of plasma samples. The analyte and 1‐phenylpropyl isothiocyanate as internal standard (IS) were subjected to chromatographic analysis on a C18 column (50 × 2.1 mm, 5 µm) using 85% methanol as mobile phase at a flow rate of 0.3 mL/min. The total analysis time for each chromatograph was 3 min and the results were linear over the studied range (5.00–250 ng/mL). The intra‐ and inter‐day precision values were acceptable as per US Food and Drug Administration guidelines. This method was successfully applied in the determination of PEITC concentrations in plasma samples from healthy chinese Volunteers. Copyright © 2014 John Wiley & Sons, Ltd.
Comparative efficacy of different acute reperfusion therapies for acute ischemic stroke: a comprehensive benefit–risk analysis of clinical trials
Authors: Tsivgoulis Georgios , Alleman John , Katsanos Aristeidis H. , Barreto Andrew D. , Kohrmann Martin , Schellinger Peter D. , Molina Carlos A , Alexandrov Andrei V.
Published: September 2014

Background

Numerous acute reperfusion therapies (RPT) are currently investigated as potential new therapeutic targets in acute ischemic stroke (AIS). We conducted a comprehensive benefit–risk analysis of available clinical studies assessing different acute RPT, and investigated the utility of each intervention in comparison to standard intravenous thrombolysis (IVT) and in relation to the onset‐to‐treatment time (OTT).

Methods

A comprehensive literature search was conducted to identify all available published, peer‐reviewed clinical studies that evaluated the efficacy of different RPT in AIS. Benefit‐to‐risk ratio (BRR), adjusted for baseline stroke severity, was estimated as the percentage of patients achieving favorable functional outcome (BRR1, mRS score: 0–1) or functional independence (BRR2, mRS score: 0–2) at 3 months divided by the percentage of patients who died during the same period.

Results

A total of 18 randomized (n = 13) and nonrandomized (n = 5) clinical studies fulfilled our inclusion criteria. IV therapy with tenecteplase (TNK) was found to have the highest BRRs (BRR1 = 5.76 and BRR2 = 6.82 for low‐dose TNK; BRR1 = 5.80 and BRR2 = 6.87 for high‐dose TNK), followed by sonothrombolysis (BRR1 = 2.75 and BRR2 = 3.38), while endovascular thrombectomy with MERCI retriever was found to have the lowest BRRs (BRR1 range, 0.31–0.65; BRR2 range, 0.52–1.18). A second degree negative polynomial correlation was detected between favorable functional outcome and OTT (R2 value: 0.6419; P < 0.00001) indicating the time dependency of clinical efficacy of all reperfusion therapies.

Conclusion

Intravenous thrombolysis (IVT) with TNK and sonothrombolysis have the higher BRR among investigational reperfusion therapies. The combination of sonothrombolysis with IV administration of TNK appears a potentially promising therapeutic option deserving further investigation.
5‐Hydroxymethyl‐2′‐Deoxyuridine Residues in the Thrombin Binding Aptamer: Investigating Anticoagulant Activity by Making a Tiny Chemical Modification
Authors: Virgilio Antonella , Petraccone Luigi , Scuotto Maria , Vellecco Valentina , Bucci Mariarosaria , Mayol Luciano , Varra Michela , Esposito Veronica , Galeone Aldo
Published: September 2014

We report an investigation into analogues of the thrombin binding aptamer (TBA). Individual thymidines were replaced by the unusual residue 5‐hydroxymethyl‐2′‐deoxyuridine (hmU). This differs from the canonical thymidine by a hydroxyl group on the 5‐methyl group. NMR and CD data clearly indicate that all TBA derivatives retain the ability to fold into the “chair‐like” quadruplex structure. The presence of the hmU residue does not significantly affect the thermal stability of the modified aptamers compared to the parent, except for analogue H9, which showed a marked increase in melting temperature. Although all TBA analogues showed decreased affinities to thrombin, H3, H7, and H9 proved to have improved anticoagulant activities. Our data open up the possibility to enhance TBA biological properties, simply by introducing small chemical modifications.
Palladium Nanoparticles Supported on Magnesium Hydroxide Fluorides: A Selective Catalyst for Olefin Hydrogenation
Authors: Acham Vaibhav R. , Biradar Ankush V. , Dongare Mohan K. , Kemnitz Erhard , Umbarkar Shubhangi B.
Published: September 2014

A one‐pot synthesis of palladium nanoparticles supported on magnesium hydroxide fluoride has been performed with the fluorolytic sol–gel method. The prepared catalysts were characterized by using various physicochemical techniques. The sol–gel method led to high surface area (>135 m2 g−1), mesoporous catalysts (pore volume=0.19–0.23 cm3 g−1, pore diameter=3–5 nm) with uniformly dispersed palladium nanoparticles approximately 2 nm in diameter on the surface. The catalysts synthesized by using different concentrations of aqueous hydrofluoric acid exhibited changing surface and acidic properties. Very high dispersion of palladium on magnesium fluoride (47 %) was obtained with 1 wt % palladium loading. The catalysts were used for hydrogenation of various olefins in the presence of other organic functionalities at room temperature and atmospheric hydrogen pressure. Various substituted olefins were hydrogenated with almost 100 % conversion and selectivity. The catalysts were recycled efficiently over five cycles without appreciable loss in catalytic activity. There was no palladium leaching under the reaction conditions, which was confirmed by inductively coupled plasma atomic emission spectroscopy analysis. Activation of olefin on the catalyst surface could not be observed by in situ FTIR studies, indicating facile activation of hydrogen on the palladium supported on magnesium hydroxide fluoride.
Operando X‐ray Absorption Spectroscopy Studies of Sintering for Supported Copper Catalysts during Liquid‐phase Reaction
Authors: O'Neill Brandon J. , Miller Jeffrey T. , Dietrich Paul J. , Sollberger Fred G. , Ribeiro Fabio H. , Dumesic James A.
Published: September 2014

The front cover artwork for Issue 09/2014 is provided by a collaboration of groups at the University of Wisconsin–Madison, Argonne National Laboratory, and Purdue University, as part of the Institute of Atom‐Efficient Chemical Transformations (IACT). The image shows the sintering of copper nanoparticles during liquid‐phase hydrogenation of furfural to furfuryl alcohol, as measured continuously at the Advanced Photon Source at Argonne National Laboratory (pictured in the background). See the Communication itself at http://dx.doi.org/10.1002/cctc.201402356.
Interactions of Bis(2,4,4‐trimethylpentyl)dithiophosphinate with NdIII and CmIII in a Homogeneous Medium: A Comparative Study of Thermodynamics and Coordination Modes
Authors: Xu Chao , Rao Linfeng
Published: September 2014

Complexation of NdIII and CmIII with purified Cyanex301 (ammonium bis(2,4,4‐trimethylpentyl)dithiophosphinate, denoted as HL) was studied in 1 % v/v water/ethanol under identical conditions by spectrophotometry and microcalorimetry. For NdIII, three successive complexes, NdL2+, NdL2+, and NdL3, formed in the solution. In contrast, four complexes, CmL2+, CmL2+, CmL3, and CmL4− formed during the titration with Cm. Fluorescence lifetime measurements provided additional insight into the complexation of CmIII with Cyanex301. The stepwise stability constants for the CmLj(3−j)+ (j=1–3) complexes are about one order of magnitude higher than the corresponding NdLj(3−j)+ complexes. The enthalpies of complexation are endothermic for both NdIII and CmIII, suggesting that the energy required for desolvation exceeds the energy gained from the cation/ligand combination. Specifically, the enthalpy of complexation for CmL2+ is 3.5 kJ mol−1 less endothermic than that of NdL2+, implying stronger covalent interaction in CmL2+ than NdL2+. However, the enthalpies of complexation for CmL2+ and NdL2+ are nearly identical, and the enthalpy of complexation for CmL3(aq) becomes more endothermic than that for NdL3(aq). The observations suggest that, in the ethanol/water media, the overall energetics of the CmIII/NdIII complexation with Cyanex301 could depend on a number of factors, including the extent of covalency, the degree of desolvation, and the coordination modes.
Kinetico‐Mechanistic Insights on the Assembling Dynamics of Allyl‐Cornered Metallacycles: The PtNpy Bond is the Keystone
Authors: Angurell Inmaculada , Ferrer Montserrat , Gutiérrez Albert , Martínez Manuel , Rocamora Mercè , Rodríguez Laura , Rossell Oriol , Lorenz Yvonne , Engeser Marianne
Published: September 2014

The square‐like homo‐ and heterometallamacrocycles [{Pd(η3‐2‐Me‐C3H4)(Ln)2}2{M(dppp)}2](CF3SO3)6 (dppp=1,3‐bis(diphenylphosphino)propane) and [{Pd(η3‐2‐Me‐C3H4)(L1)2}2{M(PPh3)2}2](CF3SO3)6 [py=pyridine, M=Pd, Pt, Ln=4‐PPh2py (L1), 4‐C6F4PPh2py (L2)] containing allyl corners were synthesised by antisymbiotic self‐assembly of the different palladium and platinum metallic corners and the ambidentate N,P ligands. All the synthesised assemblies displayed a complex dynamic behaviour in solution, the rate of which is found to be dependent on the electronic and/or steric nature of the different building blocks. A kinetico‐mechanistic study by NMR line shape analysis of the dynamics of some of these assemblies was undertaken in order to determine the corresponding thermal activation parameters. Both an enhanced thermodynamic stability and slower dynamics were observed for platinum‐pyridine‐containing species when compared with their palladium analogues. Time‐dependent NMR spectroscopy in combination with ESI mass spectrometry was used to study the exchange between the assemblies and their building blocks, as well as that occurring between different metallamacrocycles. Preliminary studies were carried out on the activity of some of the metallamacrocyclic compounds as catalytic precursors in the allylic substitution reaction, and the results compared with that of the monometallic allylic corner [Pd(η3‐2‐Me‐C3H4)(L1)2]+.
Easy Entry into Reduced Ar‐BIANH2 Compounds: A New Class of Quinone/Hydroquinone‐Type Redox‐Active Couples with an Easily Tunable Potential
Authors: Viganò Marta , Ferretti Francesco , Caselli Alessandro , Ragaini Fabio , Rossi Manuela , Mussini Patrizia , Macchi Piero
Published: September 2014

Ar‐BIANH2 bearing different substituents on the aryl rings have been synthesized in high yield by reduction of the corresponding bis(aryl)acenaphthenequinonediimine (Ar‐BIAN) compounds. The structure of p‐CH3C6H4‐BIANH2 in the solid state was determined by X‐ray diffraction. An exhaustive voltammetric investigation of the two parallel BIAN and BIANH2 series afforded a first rationalization of the redox properties of these molecules, highlighting their analogies with quinone/hydroquinone systems. Such analogies, in combination with the much more negative reduction potential range of Ar‐BIAN compounds with respect to quinones, can afford to extend the range of reduction potentials so far obtainable by the use of quinones.
Periodic Perturbation of Chemical Oscillators: Entrainment and Induced Synchronization
Authors: Makki Rabih , Muñuzuri Alberto P. , Perez‐Mercader Juan
Published: September 2014

It is well known that a large number of catalyst‐carrying beads immersed in an oscillatory chemical medium (Belousov–Zhabotinsky reaction) display collective oscillatory behavior. Using a light sensitive version of BZ, we show that this collective behavior can be entrained to an external light source with an oscillatory intensity. Thus, the emerging collective behavior can be controlled by an external perturbation.
A Multicomponent Conjugation Strategy to Unique N‐Steroidal Peptides: First Evidence of the Steroidal Nucleus as a β‐Turn Inducer in Acyclic Peptides
Authors: Rivera Daniel G. , Vasco Aldrin V. , Echemendía Radell , Concepción Odette , Pérez Carlos. S. , Gavín José A. , Wessjohann Ludger A.
Published: September 2014

Constraining small peptides into specific secondary structures has been a major challenge in peptide ligand design. So far, the major solution for decreasing the conformational flexibility in small peptides has been cyclization. An alternative is the use of topological templates, which are able to induce and/or stabilize peptide secondary structures by means of covalent attachment to the peptide. Herein a multicomponent strategy and structural analysis of a new type of peptidosteroid architecture having the steroid as N‐substituent of an internal amide bond is reported. The approach comprises the one‐pot conjugation of two peptide chains (or amino acid derivatives) to aminosteroids by means of the Ugi reaction to give a unique family of N‐steroidal peptides. The conjugation efficiency of a variety of peptide sequences and steroidal amines, as well as their consecutive head‐to‐tail cyclization to produce chimeric cyclopeptide–steroid conjugates, that is, macrocyclic lipopeptides, was assessed. Determination of the three‐dimensional structure of an acyclic N‐steroidal peptide in solution proved that the bulky, rigid steroidal template is capable of both increasing significantly the conformational rigidity, even in a peptide sequence as short as five amino acid residues, and inducing a β‐turn secondary structure even in the all‐s‐trans isomer. This report provides the first evidence of the steroid skeleton as β‐turn inducer in linear peptide sequences.
Cationic Bis‐N‐Heterocyclic Carbene (NHC) Ruthenium Complex: Structure and Application as Latent Catalyst in Olefin Metathesis
Authors: Rouen Mathieu , Queval Pierre , Falivene Laura , Allard Jessica , Toupet Loïc , Crévisy Christophe , Caijo Frédéric , Baslé Olivier , Cavallo Luigi , Mauduit Marc
Published: September 2014

An unexpected cationic bis‐N‐heterocyclic carbene (NHC) benzylidene ether based ruthenium complex (2 a) was prepared through the double incorporation of an unsymmetrical unsaturated N‐heterocyclic carbene (U2‐NHC) ligand that bore an N‐substituted cyclododecyl side chain. The isolation and full characterization (including X‐ray diffraction studies) of key synthetic intermediates along with theoretical calculations allowed us to understand the mechanism of the overall cationization process. Finally, the newly developed complex 2 a displayed interesting latent behavior during ring‐closing metathesis, which could be “switched on” under acidic conditions.
Cross‐Metathesis/Isomerization/Allylboration Sequence for a Diastereoselective Synthesis of Anti‐Homoallylic Alcohols from Allylbenzene Derivatives and Aldehydes
Authors: Hemelaere Rémy , Carreaux François , Carboni Bertrand
Published: September 2014

We describe a highly diastereoselective approach to anti‐homoallylic alcohols from allylbenzene derivatives and aldehydes. The strategy is based on a cross‐metathesis/isomerization/allylboration sequence catalyzed successively by ruthenium and iridium. This methodology provides another way to access this class of compounds, which leads to the preparation of hitherto‐unknown homoallylic alcohols without the requirement to control the stereochemistry of the 1‐alkenyl boronate intermediates. Our study towards an enantioselective version of this sequential reaction is also reported.
Titanium Salan Catalysts for the Asymmetric Epoxidation of Alkenes: Steric and Electronic Factors Governing the Activity and Enantioselectivity
Authors: Talsi Evgenii P. , Samsonenko Denis G. , Bryliakov Konstantin P.
Published: September 2014

A new insight into the highly enantioselective (up to >99.5 % ee) epoxidation of olefins in the presence of chiral titanium(IV) salan complexes is reported. A series of 14 chiral ligands with varying steric and electronic properties have been designed, and it was found that electronic effects modulate the catalytic activity (without affecting the enantioselectivity), whereas the steric properties account for the enantioselectivity of the epoxidation. Competitive oxidations of p‐substituted styrenes reveal the electrophilic nature of the oxygen‐transferring active species, with a Hammett ρ value of −0.51; the enantioselectivity is unaffected by the electron‐donating (or withdrawing) ability of the p‐substituents. Mechanistic studies provide evidence in favor of a stepwise reaction mechanism: in the first (rate‐determining) stage, olefin most probably coordinates to the active species, followed by intramolecular enantioselective oxygen transfer. The enantioselectivity increases with decreasing temperature. The modified Eyring plots for the epoxidation of styrene and (Z)‐β‐methylstyrene are linear, indicating a single, enthalpy‐controlled mechanism of stereoselectivity, with ΔΔH≠=−6.6 kJ mol−1 and −5.4 kJ mol−1, respectively.
Palladium‐Catalyzed Carbonylative [3+2+1] Annulation of N‐Aryl‐Pyridine‐2‐Amines with Internal Alkynes by CH Activation: Facile Synthesis of 2‐Quinolinones
Authors: Chen Jianbin , Natte Kishore , Spannenberg Anke , Neumann Helfried , Beller Matthias , Wu Xiao‐Feng
Published: September 2014

We describe here a novel procedure for the synthesis of highly substituted 2‐quinolinones. By this newly developed approach, 2‐quinolinone derivatives were prepared in moderate to good yields by carbonylative cyclization of N‐aryl‐pyridine‐2‐amines and internal alkynes by CH activation. Remarkably, [Mo(CO)6] was applied as a solid CO source and the reaction proceeded in an atom economic manner.
Visible‐Light Promoted Catalyst‐Free Imidation of Arenes and Heteroarenes
Authors: Song Lu , Zhang Long , Luo Sanzhong , Cheng Jin‐Pei
Published: September 2014

We described herein a catalyst‐free visible‐light photolytic protocol for the imidation of arenes and heteroarenes. N‐Bromosaccharin was identified as a viable and chemoselective nitrogen radical precursor that undergoes controllable homolytic cleavage under ambient light irradiation. The reaction can be applied to a number of arenes and heteroarenes with good chemo‐ and regioselectivity. Mechanistic studies revealed that radical chain termination by electron transfer‐proton transfer (ET‐PT) is the leading productive pathway for the reaction.
ChemInform Abstract: Structural Similarity Between Boron Oxide Bn(BO)n2‐ and Boron Hydride BnHn2‐ Dianions (n = 4—12)
Authors: Truong Ba Tai , Nguyen Minh Tam , Nguyen Minh Tho
Published: September 2014

DFT (B3LYP) calculations
ChemInform Abstract: Be2C Monolayer with Quasi‐Planar Hexacoordinate Carbons: A Global Minimum Structure.
Authors: Li Yafei , Liao Yunlong , Chen Zhongfang
Published: September 2014

Two‐dimensional Be2C monolayers, in which each carbon atom binds to six Be atoms in an almost planar fashion, are characterized by DFT calculations.
ChemInform Abstract: Transport Properties of APdCu(Se2)(Se3) (A: K and Rb): New Quaternary Copper Palladium Polyselenides.
Authors: Azam Sikander , Reshak A. H.
Published: September 2014

The electronic structure, effective mass, optical properties, and electrical transport coefficients of the title compounds are investigated by DFT calculations.
ChemInform Abstract: Non‐centrosymmetric Rb2Mn2(MoO4)3.
Authors: Bouzidi Chahira , Zid Mohamed Faouzi , Driss Ahmed , Souilem Amira
Published: September 2014

The title compound is prepared by solid state reaction of a stoichiometric mixture of Mn(OAc)3, (NH4)2Mo4O13, and Rb2CO3 (923 K, 7 d).
ChemInform Abstract: β‐K3Fe (MoO4)2Mo2O7.
Authors: Souilem Amira , Zid Mohamed Faouzi , Driss Ahmed
Published: September 2014

The title compound is obtained by solid state reaction of K2CO3, Fe(NO3)3, and (NH4)2Mo2O7 in a ratio of K:Fe:Mo = 3:1:6 (porcelain crucible, 1126 K, 1 d).
ChemInform Abstract: A Single‐Component White‐Emitting CaSr2Al2O6:Ce3+, Li+, Mn2+ Phosphor via Energy Transfer.
Authors: Li Yanyan , Shi Yurong , Zhu Ge , Wu Quansheng , Li Hao , Wang Xicheng , Wang Qian , Wang Yuhua
Published: September 2014

Samples of CaSr2Al2O6:xCe3+,xLi+ (0.01 ≤ x ≤ 0.09) and CaSr2Al2O6:0.03Ce3+,0.03Li +,yMn2+ (0 ≤ y ≤ 0.07) are prepared by solid state reactions of CaCO3, SrCO3, Al2O3, CeO2, and MnCO3 (alumina crucibles, 10%H2/N2, 1400 °C, 6 h).
ChemInform Abstract: Transmetalation of Aqueous Inorganic Clusters: A Useful Route to the Synthesis of Heterometallic Aluminum and Indium Hydroxo—Aquo Clusters.
Authors: Kamunde‐Devonish Maisha K. , Jackson Milton N. Jr. , Mensinger Zachary L. , Zakharov Lev N. , Johnson Darren W.
Published: September 2014

[Al7In6(μ3‐OH)6 (μ‐OH)18(H2O)24] (NO3)15 hydroxy‐aquo clusters (Al7In6) are prepared by evaporation of a MeOH solutions of [Al13(μ3‐OH)6(μ‐OH)18 (H2O)24](NO3)15 (Al13) and In(NO3)3 (open system, 25 °C, several days; 10% yield).
ChemInform Abstract: Preparation, Structural Characterization, and Ion‐Exchange Properties of Two New Zeolite‐like 3D Frameworks Constructed by ε‐Keggin‐Type Polyoxometalates with Binding Metal Ions, H11.4 [ZnMo12O40Zn2]1.5‐ and H7.5 [Mn0.2Mo12O40Mn2] 2.1‐.
Authors: Zhang Zhenxin , Sadakane Masahiro , Murayama Toru , Sakaguchi Norihito , Ueda Wataru
Published: September 2014

The new compounds (IV) and (VII) are characterized by powder XRD, FTIR, and Raman spectroscopy.
ChemInform Abstract: Synthesis of Silver—Graphene Nanocomposite and Its Catalytic Application for the One‐Pot Three‐Component Coupling Reaction and One‐Pot Synthesis of 1,4‐Disubstituted 1,2,3‐Triazoles in Water.
Authors: Salam Noor , Sinha Arjyabaran , Roy Anupam Singha , Mondal Paramita , Jana Nikhil R. , Islam Sk Manirul
Published: September 2014

A new heterogeneous graphene based catalyst with silver nanoparticles is developed and successfully applied as catalyst for the three component condensation of aldehydes, terminal alkynes, and amines as well as the 1,3‐dipolar cycloaddition of organic azides with terminal alkynes.
ChemInform Abstract: Enantioselective Addition of Diethylzinc to Aromatic Aldehydes Catalyzed by C2‐Symmetric Chiral Diols.
Authors: Goek Yasar , Kekec Levent
Published: September 2014

Optically pure diols (I) catalyze the addition of diethylzinc to aromatic aldehydes to give the corresponding alcohols with up to 99% enantiomeric excess.
ChemInform Abstract: Silver Triflate‐Catalyzed Cyclization of 2‐Amino‐6‐propargylamineazines Leading to Iminoimidazoazines.
Authors: Chioua Mourad , Samadi Abdelouahid , Soriano Elena , Infantes Lourdes , Marco‐Contelles Jose
Published: September 2014

The scope, limitations, and mechanism of the title cyclization reaction are described.
ChemInform Abstract: Molecular Iodine Promoted Divergent Synthesis of Benzimidazoles, Benzothiazoles, and 2‐Benzyl‐3‐phenyl‐3,4‐dihydro‐2H‐benzo[e][1,2,4]thiadiazines.
Authors: Naresh Gunaganti , Kant Ruchir , Narender Tadigoppula
Published: September 2014

A simple protocol is developed for the synthesis of benzimidazoles and benzothiazoles from readily available precursors.
ChemInform Abstract: Broensted Acid Catalyzed Azlactone Ring Opening by Nucleophiles.
Authors: Pereira Adriane A. , de Castro Pedro P. , de Mello Amanda C. , Ferreira Bruno R. V. , Eberlin Marcos N. , Amarante Giovanni W.
Published: September 2014

Camphorsulfonic acid catalyzed the ring opening of azlactones by alcohols or amines providing the corresponding esters or amides, respectively.
ChemInform Abstract: A General Approach Towards Catechol and Pyrogallol Through Ruthenium‐ and Palladium‐Catalyzed C—H Hydroxylation by Weak Coordination.
Authors: Yang Xinglin , Sun Yonghui , Chen Zhang , Rao Yu
Published: September 2014

The carbamate group is found to be superior over esters and ketone groups in terms of directing ability in the hydroxylation reactions providing catechol and pyrogallol derivatives with excellent regioselectivity.
ChemInform Abstract: Microfluidic Hydrogenation Reactions by Using a Channel‐Supported Rhodium Catalyst.
Authors: Haywood Tom , Miller Philip W.
Published: September 2014

The hydrogenation of olefines and unsaturated ketones is improved by a rhodium‐coated microfluidic device compared to the homogeneous Wilkinson′s catalyst.
ChemInform Abstract: Copper‐Mediated Trimethylsilyl Azide in Amination of Bromoflavonoids to Synthesize Unique Aminoflavonoids.
Authors: Shih Tzenge‐Lien , Chou Chi‐En , Liao Wen‐Yu , Hsiao Chih‐Ang
Published: September 2014

The synthesis of aminoflavonoids from the corresponding bromoflavones and bromoflavanols, respectively is studied.
ChemInform Abstract: Chitosan‐Supported Fe3O4 Nanoparticles: A Magnetically Recyclable Heterogeneous Nanocatalyst for the Syntheses of Multifunctional Benzimidazoles and Benzodiazepines.
Authors: Maleki Ali , Ghamari Nakisa , Kamalzare Maryam
Published: September 2014

A magnetically recoverable and biodegradable heterogeneous nanocatalyst is prepared and characterized.
ChemInform Abstract: Three‐Component Reaction for the Synthesis of Diverse β‐Unsaturated α‐Amino Esters.
Authors: Stefani Helio A. , Manarin Flavia , Sousa Ariane C. S. , Souza Frederico B. , Ferraz Witor Ribeiro
Published: September 2014

A convenient one‐pot operation allows the three‐component reaction of fluoroborate salts, aromatic amine and ethyl glyoxylate to provide alkynyl‐ alkenyl‐, and allyl‐2‐amino esters under mild reaction conditions.
ChemInform Abstract: An Efficient, Practical, and Enantioselective Method for Synthesis of Homoallenylamides Catalyzed by an Aminoalcohol‐Derived, Boron‐Based Catalyst.
Authors: Wu Hao , Haeffner Fredrik , Hoveyda Amir H.
Published: September 2014

The first general enantioselective allenyl addition to a range of aromatic and aliphatic aldehyde derived imines is presented.
ChemInform Abstract: Silver(I)‐Catalyzed Hydroazidation of Ethynyl Carbinols: Synthesis of 2‐Azidoallyl Alcohols.
Authors: Liu Zhenhua , Liu Jianquan , Zhang Lin , Liao Peiqiu , Song Jinna , Bi Xihe
Published: September 2014

A chemo‐ and regioselective hydroazidation of differently substituted ethynylcarbinols is achieved by Ag(I)‐catalyzed reaction with TmsN3 to yield 2‐azidoallyl alcohols.
ChemInform Abstract: CuBr‐Promoted Formal Hydroacylation of 1‐Alkynes with Glyoxal Derivatives: An Unexpected Synthesis of 1,2‐Dicarbonyl‐3‐enes.
Authors: Chen Shufeng , Li Xiaojie , Zhao Haiying , Li Baoguo
Published: September 2014

This novel reaction proceeds with absolute E‐selectivity.
ChemInform Abstract: Ligand‐Controlled C(sp3)‐H Arylation and Olefination in Synthesis of Unnatural Chiral α‐Amino Acids.
Authors: He Jian , Li Suhua , Deng Youqian , Fu Haiyan , Laforteza Brian N. , Spangler Jillian E. , Homs Anna , Yu Jin‐Quan
Published: September 2014

The presented Pd catalyzed reaction allows the mono and diarylation by choosing pyridine or quinoline ligands.
ChemInform Abstract: Preparation of tert‐Butyl Esters via Pd‐Catalyzed tert‐Butoxycarbonylation of (Hetero)aryl Boronic Acid Derivatives.
Authors: Li Xinjian , Zou Dapeng , Zhu Helong , Wang Yaping , Li Jingya , Wu Yangjie , Wu Yusheng
Published: September 2014

A convenient synthesis of aryl‐ and heteroaryl tert‐butyl esters from boronic acids (I) or boronic acid pinacol esters (IV) under mild nontoxic conditions with minimal waste production is presented.
ChemInform Abstract: Copper‐Catalyzed Coupling of Oxime Acetates with Sodium Sulfinates: An Efficient Synthesis of Sulfone Derivatives.
Authors: Tang Xiaodong , Huang Liangbin , Xu Yanli , Yang Jidan , Wu Wanqing , Jiang Huanfeng
Published: September 2014

Oxime acetates undergo a novel Cu‐catalyzed reaction with tolylsulfinate (II) to yield tosylated enamines of type (III).
ChemInform Abstract: Sulfonated Poly(4‐vinylpyridine) Heteropolyacid Salts: A Reusable Green Solid Catalyst for Mannich Reaction.
Authors: Li Wen‐You , Zong Ying‐Xiao , Wang Jun‐Ke , Niu Yu‐Ying
Published: September 2014

An efficient one‐pot synthesis of β‐amino carbonyl compounds via the Mannich reaction between aromatic aldehydes, aromatic ketones, and aromatic amines is developed using the title heteropolyacid salt as heterogeneous catalyst.
ChemInform Abstract: Palladium‐Catalyzed Benzylation of Arylboronic Acids with N,N‐Ditosylbenzylamines.
Authors: Yoon Sangeun , Hong Myeng Chan , Rhee Hakjune
Published: September 2014

The N,N‐ditosylamide group proves to be an efficient leaving group in Pd‐catalyzed benzylation of boronic acids.
ChemInform Abstract: Palladium(II) tetrakis(4‐N,N,N‐Trimethylammoniumphenylene)porphyrin Supported on Ion‐Exchange Resins as Efficient and Reusable Catalysts for C—C Coupling Reactions.
Authors: Sadegh Faranak , Bagheri Omid , Moghadam Majid , Mirkhani Valiollah , Tangestaninejad Shahram , Mohammadpoor‐Baltork Iraj
Published: September 2014

The reactions are also performed using the same porphyrin catalyst, but on Amberlite IR‐120 support, giving virtually comparable yields.
ChemInform Abstract: Efficient Synthesis of Functionalized 1,3‐Dihydroisobenzofurans from Salicylaldehydes: Application to the Synthesis of Escitalopram.
Authors: Wang Peng , Zhang Rui , Cai Jin , Chen Jun‐Qing , Ji Min
Published: September 2014

A facile and efficient method for the synthesis of 1,3‐dihydroisobenzofurans (III), which exhibits high functional group tolerance, is developed and applied to the preparation of escitalopram key intermediate (IIIf).
ChemInform Abstract: A Simple and Efficient Synthesis of Substituted 2,2′‐Bithiophene and 2,2′:5′,2′′‐Terthiophene.
Authors: Kostyuchenko Anastasia S. , Averkov Alexey M. , Fisyuk Alexander S.
Published: September 2014

The synthesis of bithiophene derivatives in three steps using Fiesselmann reaction for thiophene ring closure is developed.
ChemInform Abstract: A New Versatile Route to the Synthesis of a Novel Series of Highly Substituted 1,1′‐Carbonylbispyrazole Derivatives
Authors: Saberi Sattar , Eshghi Hossein , Rahimizadeh Mohamad , Abnous Khalil
Published: September 2014

via cyclocondensation of pyrazole‐1‐carbohydrazides with α,β‐unsaturated nitriles
ChemInform Abstract: CuO Nanoparticle Catalyzed Synthesis of 2H‐Indazoles under Ligand Free Conditions.
Authors: Khatun Nilufa , Gogoi Anupal , Basu Pallabita , Das Prasenjit , Patel Bhisma K.
Published: September 2014

The catalyst can be recycled and is reused up to three times with slightly decreasing yields.
ChemInform Abstract: Stepwise Formation of 1,3‐Diazolium‐4‐thiolates by Muenchnone Cycloadditions: Promising Candidates for Nonlinear Optics.
Authors: Cantillo David , Avalos Martin , Babiano Reyes , Cintas Pedro , Jimenez Jose L. , Light Mark E. , Palacios Juan C. , Porro Rocio
Published: September 2014

DFT calculations support a predominant stepwise mechanism competing with a concerted process leading to isomeric products (III) and (IV) for instance.
ChemInform Abstract: Reaction of Alkynes and Azides: Not Triazoles Through Copper—Acetylides but Oxazoles Through Copper—Nitrene Intermediates.
Authors: Haldon Estela , Besora Maria , Cano Israel , Cambeiro Xacobe C. , Pericas Miquel A. , Maseras Feliu , Nicasio M. Carmen , Perez Pedro J.
Published: September 2014

Two copper complexes for the regioselective formation of 2,5‐disubstituted oxazoles from carbonyl azides and terminal alkynes are developed.