bluuebunny/crossref_metadata_2025 huggingface dataset:
N‐{[2‐(4‐Phenyl‐piperazin‐1‐yl)‐ethyl]‐phenyl}‐arylamides with Dopamine D2 and 5‐Hydroxytryptamine 5HT1A Activity: Synthesis, Testing, and Molecular Modeling
Authors: Sukalovic Vladimir , Bogdan Anca Elena , Tovilovic Gordana , Ignjatovic Djurdjica , Andric Deana , Kostic‐Rajacic Sladjana , Soskic Vukic
Published: October 2013

The ratio of affinities toward the dopamine D2 and the 5‐hydroxytryptamine 5‐HT1A receptors is one of the important parameters that determine the efficiency of antipsychotic drugs. Here, we present the synthesis of ortho‐, meta‐, and para‐N‐{[2‐(4‐phenyl‐piperazin‐1‐yl)‐ethyl]‐phenyl}‐arylamides and their structure–activity relationship studies on dopamine D2 and 5‐hydroxytryptamine 5‐HT1A receptors. It was shown that the biological activity of the described ligands strongly depends on their topology as well as on the nature of the heteroaryl group in the head of the molecules. Docking simulations together with conformational analysis revealed a rational explanation for the ligands' behavior. The molecular model of receptor–ligand interactions described herein provided us with a tool for the rational design of new compounds with a favorable D2/5‐HT1A profile.
Synthesis and Antiproliferative Activity of Quinolone Nucleosides Against the Human Myelogenous Leukemia K‐562 Cell Line
Authors: Wicke Lena , Engels Joachim W. , Gambari Roberto , Saab Antoine M.
Published: October 2013

A set of 6‐substituted quinolone nucleosides linked to aniline or phenol via N or O heteroatom‐bridges presenting new compounds were synthesized by palladium‐catalyzed Buchwald–Hartwig cross‐coupling reactions. 6‐Bromoquinolone nucleoside precursors, being protected by either benzoyl or TBDMS protecting groups on the ribose moiety, were subjected to different Buchwald–Hartwig conditions as the key step. Defined deprotection steps led, in good yields, to the final target compounds that carry, in position 3, either ester, acid, or amide functions. Thus, a series of novel quinolone nucleoside derivatives was obtained via a convergent synthesis route. Biological tests in human chronic myelogenous leukemia K562 cells exerted an efficient antiproliferative activity for two of them without induction of differentiation. These novel nucleosides deserve further experiments to determine their antiproliferative effects on other CML cell lines.
Geophysical–Geochemical Reconstruction of Ancient Population Size – the Early Bronze Age Settlement of Fidvár (Slovakia)
Authors: Nowaczinski Erich , Schukraft Gerd , Rassmann Knut , Hecht Stefan , Texier Fabienne , Eitel Bernhard , Bubenzer Olaf
Published: October 2013

Population estimates are a vital backdrop to our understanding of ancient societies' socio‐economic structures and development. In order to facilitate such an informational mise en scène in terms of the early Bronze Age settlement of Fidvár in southwestern Slovakia, a new geophysical–geochemical approach is presented here, the first results of which are very promising. The crux of the new methodology utilizes the population's chemical fingerprint in relation to total anthropogenic phosphorus input as a proxy for different population models. These methods suggest an early Bronze Age population of 300–600 individuals, in accordance with the comparative analysis of a magnetic survey, and also matches initial archaeological estimates. Further methodological adjustments suggest an even higher population of up to 1000 inhabitants. In light of these figures, it is likely that Fidvár was one of the centres of the early Bronze Age socio‐economic system of the northern Pannonian Basin. Copyright © 2013 John Wiley & Sons, Ltd.
Investigating confidence displays for top‐N recommendations
Authors: Shani Guy , Rokach Lior , Shapira Bracha , Hadash Sarit , Tangi Moran
Published: October 2013

Recommendation systems often compute fixed‐length lists of recommended items to users. Forcing the system to predict a fixed‐length list for each user may result in different confidence levels for the computed recommendations. Reporting the system's confidence in its predictions (the recommendation strength) can provide valuable information to users in making their decisions. In this article, we investigate several different displays of a system's confidence to users and conclude that some displays are easier to understand and are favored by most users. We continue to investigate the effect confidence has on users in terms of their perception of the recommendation quality and the user experience with the system. Our studies show that it is not easier for users to identify relevant items when confidence is displayed. Still, users appreciate the displays and trust them when the relevance of items is difficult to establish.
Entwicklung vereinfachter Materialgesetze in Form von temperaturabhängigen Spannungs‐Dehnungs‐Beziehungen für ultrahochfesten Beton
Authors: Richter Ekkehard , Zehfuß Jochen , Kampmeier Björn
Published: October 2013

Das Baustoffverhalten von Beton im Hochtemperaturbereich q ≤ 1200 °C wird i. A. mit Hilfe stationärer Druck‐ und instationärer Kriechversuche untersucht. Die unterschiedliche Versuchsdurchführung wird detailliert in den RILEM‐Empfehlungen beschrieben. Die experimentellen Ergebnisse werden anschließend in Form von temperaturabhängigen Spannungs‐Dehnungslinien aufbereitet, die die Grundlage für die numerische Berechnung des Trag‐ und Verformungsverhaltens von brandbeanspruchten Bauteilen darstellen. Bei deren Anwendung müssen die Randbedingungen beachtet werden, wie z. B. die Aufheizgeschwindigkeit. Bereits früher wurde am Beispiel von Normalbeton gezeigt, wie aus den experimentellen Ergebnissen vereinfachte temperaturabhängige Spannungs‐Dehnungslinien ermittelt werden. In diesem Beitrag wird das Vorgehen auf ultrahochfesten Beton angewendet. Die theoretischen Überlegungen und die Ableitung baustoffspezifischer Materialkennwerte werden beispielhaft an der Betonrezeptur B5Q durchgeführt.

Developing simplified materials laws in the form of temperature‐dependent stress‐strain relations for ultra high performance concrete. The behaviour of concrete as a building material at temperatures in the region of q ≤ 1200 °C is normally investigated using steady state and transient creep tests. The various experimental methods are described in detail in the RILEM recommendations. The results of the experiments are then displayed in the form of temperature‐dependent stress‐strain diagrams. These diagrams represent the basis for the numerical calculation of the load‐bearing and deformation behaviour of components exposed to fire. When such diagrams are used, the boundary conditions must also be considered, such as the heating rate. The example of normal concrete has already been used to show how simplified temperature‐dependent stress‐strain diagrams may be derived from experimental findings. The present paper applies the same procedure to ultra high performance concrete. As an example, the theoretical considerations and the derivation of building material‐specific parameters are applied to one concrete mix composition.
Untersuchungen zur Festigkeit der Klebefugen von historischem Brettschichtholz
Authors: Rug Wolfgang , Linke Gunter , Winter Leonard
Published: October 2013

Der Beitrag befasst sich mit Untersuchungen zur Festigkeit von Kaseinverleimungen von Brettschichtholz in Hetzer‐Bauweise. Kaseinverleimungen treten heutzutage nur noch im Bereich von Instandsetzungsarbeiten an historischen Brettschichtholzkonstruktionen in Erscheinung.

Eine Bewertung der Ergebnisse nach der DIN EN 392:1996 erwies sich als ungeeignet, da sich diese Norm auf moderne, auf Kunstharzen basierende Klebstoffsysteme bezieht. Um dennoch eine Bewertung vornehmen zu können, wurde auf frühere Veröffentlichungen zur Festigkeit von Kaseinverleimungen bzw. Regelwerke des Holzflugzeugbaus der 1950er‐Jahre zurückgegriffen.

Die Auswertung eigener Untersuchungen ergab, dass Kaseinverleimungen auch nach 100 Jahren Nutzungsdauer, insbesondere unter Wechselwirkung von Feuchtigkeit und chemisch‐aggressiven Medien, eine relativ hohe Tragfähigkeit und Dauerhaftigkeit aufweisen.

Studies on the strength of the adhesive joints of historic glued laminated timber

This paper presents a study on the strength of casein glue layers of glulam timber in Hetzer's construction method. Nowadays casein adhesive joints are only appearing in maintenance of historic glulam structures.

An evaluation of the results according to DIN EN 392:1996 proved unsuitable, as this standard relates to modern, synthetic resins based adhesive systems. Therefore earlier publications on the strength of casein glue respectively regulations for wooden aircrafts from the 1950s were utilized in order to be able to assess these kind of adhesive joints.

The results of this study revealed, that the casein adhesive joint has an relatively high loading capacity and durability even after 100 years especially under interaction of moisture and chemically aggressive media.
Entwurfs‐ und Konstruktionsgrundsätze von extern vorgespannten Straßenbrücken in Segmentbauart, dargestellt am Bangkok Expressway, Thailand.
Authors: Girmscheid G.
Published: October 2013

Am Beispiel einer 35 km langen Spannbeton‐Hochstraße in Segmentbauart mit externer Vorspannung und Trockenfuge werden das Prinzip und Vor‐ und Nachteile der Bauart beschrieben.
What do you mean by transcription rate?
Authors: Pérez‐Ortín José E. , Medina Daniel A. , Chávez Sebastián , Moreno Joaquín
Published: October 2013

mRNA synthesis in all organisms is performed by RNA polymerases, which work as nanomachines on DNA templates. The rate at which their product is made is an important parameter in gene expression. Transcription rate encompasses two related, yet different, concepts: the nascent transcription rate, which measures the in situ mRNA production by RNA polymerase, and the rate of synthesis of mature mRNA, which measures the contribution of transcription to the mRNA concentration. Both parameters are useful for molecular biologists, but they are not interchangeable and they are expressed in different units. It is important to distinguish when and where each one should be used. We propose that for functional genomics the use of nascent transcription rates should be restricted to the evaluation of the transcriptional process itself, whereas mature mRNA synthesis rates should be employed to address the transcriptional input to mRNA concentration balance leading to variation of gene expression.
How do taste cells lacking synapses mediate neurotransmission? CALHM1, a voltage‐gated ATP channel
Authors: Taruno Akiyuki , Matsumoto Ichiro , Ma Zhongming , Marambaud Philippe , Foskett J. Kevin
Published: October 2013

CALHM1 was recently demonstrated to be a voltage‐gated ATP‐permeable ion channel and to serve as a bona fide conduit for ATP release from sweet‐, umami‐, and bitter‐sensing type II taste cells. Calhm1 is expressed in taste buds exclusively in type II cells and its product has structural and functional similarities with connexins and pannexins, two families of channel protein candidates for ATP release by type II cells. Calhm1 knockout in mice leads to loss of perception of sweet, umami, and bitter compounds and to impaired gustatory nerve responses to these tastants. These new studies validate the concept of ATP as the primary neurotransmitter from type II cells to gustatory neurons. Furthermore, they identify voltage‐gated ATP release through CALHM1 as an essential molecular mechanism of ATP release in taste buds. We discuss these new findings, as well as unresolved issues in peripheral taste signaling that we hope will stimulate future research.
Imaging and tracing of intracellular metabolites utilizing genetically encoded fluorescent biosensors
Authors: Zhang Chang , Wei Zi‐Han , Ye Bang‐Ce
Published: October 2013

Intracellular metabolites play a crucial role in characterizing and regulating corresponding cellular activities. Tracking intracellular metabolites in real time by traditional means was difficult until the powerful toolkit of genetically encoded biosensors was developed. Over the past few decades, iterative improvements of these biosensors have been made, resulting in the effective monitoring of metabolites. In this review, we introduce and discuss the recent advances in the use of genetically encoded biosensors for tracking some key metabolites, such as ATP, cAMP, cGMP, NADH, reactive oxygen species, sugar, carbon monoxide, and nitric oxide. A brief phylogeny of fluorescent proteins and several typical construction modes for genetically encoded biosensors are also described. We also discuss the development of novel RNA‐based sensors, which are genetically encoded biosensors active at the transcriptional level.
Magnetic quantum dots in biotechnology – synthesis and applications
Authors: Mahajan Kalpesh D. , Fan Qirui , Dorcéna Jenny , Ruan Gang , Winter Jessica O.
Published: October 2013

Quantum dots (QDs) have great promise in biological imaging, and as this promise is realized, there has been increasing interest in combining the benefits of QDs with those of other materials to yield composites with multifunctional properties. One of the most common materials combined with QDs is magnetic materials, either as ions (e.g. gadolinium) or as nanoparticles (e.g. superparamagnetic iron oxide nanoparticles, SPIONs). The fluorescent property of the QDs permits visualization, whereas the magnetic property of the composite enables imaging, magnetic separation, and may even have therapeutic benefit. In this review, the synthesis of fluorescent–magnetic nanoparticles, including magnetic QDs is explored; and the applications of these materials in imaging, separations, and theranostics are discussed. As the properties of these materials continue to improve, QDs have the potential to greatly impact biological imaging, diagnostics, and treatment.
The use of rice seeds to produce human pharmaceuticals for oral therapy
Authors: Wakasa Yuhya , Takaiwa Fumio
Published: October 2013

Rice (Oryza sativa L.) is the major staple food consumed by half of the world's population. Rice seeds have gained recent attention as bioreactors for the production of human pharmaceuticals such as therapeutic proteins or peptides. Rice seed production platforms have many advantages over animal cell or microbe systems in terms of cost‐effectiveness, scalability, safety, product stability and productivity. Rice seed‐based human pharmaceuticals are expected to become innovative therapies as edible drugs. Therapeutic proteins can be sequestered within natural cellular compartments in rice seeds and protected from harsh gastrointestinal environments. This review presents the state‐of‐the‐art on the construction of gene cassettes for accumulation of pharmaceutical proteins or peptides in rice seeds, the generation of transgenic rice plants, and challenges involved in the use of rice seeds to produce human pharmaceuticals.
Metabolic Fate of Depsides and Alkaloid Constituents in Aqueous Extracts from Mercurialis perennis L. during Fermentation
Authors: Lorenz Peter , Conrad Jürgen , Stintzing Florian C.
Published: October 2013

Dog's mercury (Mercurialis perennis L.) is an old medicinal plant, nowadays used in complementary medicine. Aqueous fermented extracts of the plant are being mainly applied in remedies to treat external inflammations, but a thorough phytochemical characterization is still lacking. Therefore, the conversion of characteristic compound classes from M. perennis extracts during fermentation and storage was investigated. The microbial transformation of the two main depsides phaselic acid (=(2R)‐O‐[(E)‐caffeoyl]malic acid; 1) and mercurialis acid (=(2R)‐[(E)‐caffeoyloxy]glutaric acid; 2) was monitored by HPLC‐DAD. The degradation followed a second‐order kinetic, and the calculated half‐life periods of both constituents were 67 and 30 months, respectively. Several depside metabolites were detected by GC/MS in AcOEt extracts as tBuMe2Si (TBDMS) derivatives after derivatization, mainly dihydrocinnamic acids. Moreover, numerous α‐hydroxy acids were found, allegedly as degradation products from amino acids or peptides. The microbial alteration of the main alkaloid hermidin was also examined. After three days of fermentation, three novel N‐metabolites were formed and thoroughly assigned in CH2Cl2 extracts as a mixture of 3‐ethylhermidin, 3‐ethylhermidin quinone, and (E/Z)‐3‐ethylidenehermidin by GC/MS and NMR methods, as well as by means of total synthesis. A mechanism for the formation of these N‐metabolites starting from dimeric hermidin oxidation products is proposed. The obtained results reveal the complex pathways plant constituents may undergo during the fermentation of the extracts.
Variability of the Root Essential Oils of Seseli rigidumWaldst. & Kit. (Apiaceae) from Different Populations in Serbia
Authors: Marčetić Mirjana D. , Lakušić Branislava S. , Lakušić Dmitar V. , Kovačević Nada N.
Published: October 2013

The chemical compositions of the essential oils of seven natural populations of Seseli rigidum were analyzed. The essential‐oil yield ranged from 0.16 to 2.09%. Analysis of variance (ANOVA) revealed that there were no statistically significant differences in the mean essential‐oil yields between the populations, and no significant influence of the climate or soil type on the oil yield was observed. In all 67 analyzed samples, the polyacetylene falcarinol was the main compound, followed by octanal, methyl linoleate, α‐muurolene, 3‐butylphthalide, falcarinone, muurola‐4,10(14)‐dien‐1β‐ol, β‐sesquiphellandrene, salvial‐4(14)‐en‐1‐one, δ‐amorphene, spathulenol, and isospathulenol. The principal component analysis (PCA), the canonical discriminant analysis (CDA), and the cluster analysis (CA) revealed differentiation between the populations based on the climate. Three groups of populations were formed; the first group was composed of samples growing in regions with a humid climate, with oils having high falcarinol and low sesquiterpene contents, and the second and third groups comprised samples exposed to semi‐arid climate, with oils characterized by a lower falcarinol and higher α‐muurolene, δ‐amorphene, β‐sesquiphellandrene, and salvial‐4(14)‐en‐1‐one contents. The semi‐arid populations were divided into two groups, which were distinguished based on the oil contents of sesquiterpenes, falcarinone, and 3‐butylphthalide. On the other hand, no clear separation between populations based on the different soil types could be observed.
Odor Qualities and Thresholds of Physiological Metabolites of 1,8‐Cineole as an Example for StructureActivity Relationships Considering Chirality Aspects
Authors: Kirsch Frauke , Buettner Andrea
Published: October 2013

The present study aimed at analyzing the odor properties of a group of physiological human metabolites of the odorant 1,8‐cineole: 2,3‐dehydro‐, α2,3‐epoxy‐, α/β2‐hydroxy‐, α3‐hydroxy‐, 4‐hydroxy‐, 7‐hydroxy‐, 9‐hydroxy‐, 2‐oxo‐, and 3‐oxo‐1,8‐cineole. These metabolites constitute a group of structurally closely related molecules, which differ mainly in nature and position of O‐containing functional groups. They thus offer the possibility to correlate odor properties with molecular structure, i.e., to establish structureodor relationships of compounds that are biologically generated from a potent odorant as parent substance. Generally, the metabolites preserved the eucalyptus‐like odor quality of 1,8‐cineole but showed additional odor notes such as sweet, citrus‐like, plastic‐like, earthy, musty, and faecal, which made them distinguishable. The individual enantiomers of chiral molecules also exhibited different odors. With the exception of 2,3‐dehydro‐1,8‐cineole, all metabolites showed a highly decreased odor threshold in comparison to 1,8‐cineole. The determination of odor qualities and odor thresholds was accomplished by gas chromatography/olfactometry (GC/O) on achiral and chiral GC capillaries. The results were correlated with common theories on structureodor relationships.
Gates and Binding Pockets for Nitric Oxide with Cytochrome c′, According to Molecular Dynamics
Authors: Pietra Francesco
Published: October 2013

Random‐acceleration molecular‐dynamics (RAMD) simulations with models of homodimeric 6‐ligated distal‐NO and 5‐ligated proximal‐NO cytochrome c′ complexes, in TIP3 H2O, showed two distinct, non‐intercommunicating worlds. In the framework of a long cavity formed by four protein helices with heme at one extremity, NO was observed to follow different pathways with the two complexes to reach the solvent. With the 6‐ligated complex, NO was observed to progress by exploiting protein internal channels created by thermal fluctuations, and be temporarily trapped into binding pockets before reaching the preferred gate at the heme end of the cavity. In contrast, with the 5‐ligated complex, NO was observed to surface the solvent‐exposed helix 7, up to a gate at the other extremity of the protein, only occasionally finding an earlier, direct way out toward the solvent. That only bulk NO gets involved in forming the 5‐ligated proximal‐NO complex is in agreement with previous experimental observations, while the occurrence of binding pockets suggests that also reservoir NO might play a role with the distal‐NO complex.
Efficient Ruthenium Nanocatalysts in Liquid–Liquid Biphasic Hydrogenation Catalysis: Towards a Supramolecular Control through a Sulfonated Diphosphine–Cyclodextrin Smart Combination
Authors: Guerrero Miguel , Coppel Yannick , Chau Nguyet Tran Thanh , Roucoux Alain , Denicourt‐Nowicki Audrey , Monflier Eric , Bricout Hervé , Lecante Pierre , Philippot Karine
Published: October 2013

The combination between a sulfonated diphosphine (L) and a cyclodextrin (CD) allowed the preparation of very stable water‐soluble ruthenium nanoparticles (RuNPs) that displayed pertinent catalytic performances in hydrogenation of unsaturated substrates with a supramolecular control effect of the cyclodextrin. For comparison purpose, the RuNPs were produced by hydrogenation of the organometallic [Ru(1,5‐cyclooctadiene)(1,3,5‐cyclooctatriene)] complex under mild conditions (3 bar H2; room temperature) and in the presence of L or a L/CD mixture as stabilizer leading to Ru/L and Ru/L/CD systems, respectively. The so‐obtained nanoparticles were fully characterized by complementary techniques. Interestingly, NMR investigations evidenced 1) the strong coordination of the sulfonated diphosphine ligand at the metallic surface and 2) in the presence of cyclodextrin, the formation of an inclusion complex between L and CD that modified the coordination mode of the diphosphine. The investigation of both RuNPs systems in biphasic hydrogenation of unsaturated substrates pointed out relevant differences in terms of reactivity, thus evidencing the influence of the supramolecular interaction at the metallic surface on the catalytic performances of the nanocatalysts. This work took advantage of the supramolecular properties of a cyclodextrin to modulate the surface reactivity of diphosphine‐stabilized ruthenium nanoparticles and may open new opportunities in the field of nanocatalysis.
Fixed‐Bed Multi‐Tubular Reactors for Oxidative Dehydrogenation in Ethylene Process
Authors: Fattahi M. , Kazemeini M. , Khorasheh F. , Darvishi A. , Rashidi A. M.
Published: October 2013

An industrial‐scale reactor for ethylene production was modeled using the oxidative dehydrogenation of ethane (ODHE) in a multi‐tubular reactor system, examining a variety of parameters affecting reactor performance. The model showed that a double‐bed multi‐tubular reactor with intermediate air injection scheme was superior to a single‐bed design, due to the increased ethylene selectivity while operating under lower oxygen partial pressures. The optimized reactor length for 100 % oxygen conversion was theoretically determined for both reactor designs. The use of a distributed oxygen feed with a limited number of injection points indicated a significant improvement on the reactor performance in terms of ethane conversion and ethylene selectivity. This concept also overcame the reactor runaway temperature problem and enabled operations over a wider range of conditions to obtain enhanced ethylene production.
Industrial Xylene/Ethylbenzene Isomerization Unit Using a Radial‐Flow Reactor and EUO‐Type Zeolite
Authors: Gonçalves J. C. , Rodrigues A. E.
Published: October 2013

A mathematical model based on 34 days continuous operation of an industrial isomerization unit was developed. The unit involves a radial‐flow reactor with a catalyst capable of converting xylenes and ethylbenzene to mixed xylenes. The catalyst contains EU‐1 zeolite, platinum, and alumina as binder. Two reactions are considered, i.e., ethylbenzene isomerization and xylene isomerization. The rates are based on the Hougen‐Watson model according to the literature. An optimization procedure based on the trust‐region‐reflective algorithm was carried out in order to obtain new kinetic constants that minimize the difference between the actual and the calculated values. The standard error of the parameters estimated was calculated through the deleted‐one Jackknife method.
Multiply Nitrated High‐Energy Dense Oxidizers Derived from the Simple Amino Acid Glycine
Authors: Baumann Andreas , Erbacher Anna , Evangelisti Camilla , Klapötke Thomas M. , Krumm Burkhard , Rest Sebastian F. , Reynders Martin , Sproll Véronique
Published: October 2013

Various energetic polynitro esters, carbamates, and nitrocarbamates that were derived from the amino acid glycine were fully characterized by single‐crystal X‐ray diffraction, vibrational spectroscopy (IR and Raman), multinuclear NMR spectroscopy, elemental analysis, and differential scanning calorimetry (DSC). Owing to their positive oxygen balance, the suitability of these compounds as potential oxidizers in energetic formulations was investigated and discussed. In addition, the heats of formation of the products were calculated by using the Gaussian 09 program package at the CBS‐4M level of theory. From these values and the calculated densities (from the X‐ray data), several detonation parameters, such as detonation pressure, velocity, energy, and temperature, were computed by using the EXPLO5 code. Furthermore, their sensitivities towards impact, friction, and electrostatic discharge were tested by using a drop hammer, a friction tester (both BAM certified), and a small‐scale electrical‐discharge device, respectively.
Luminescent Amphiphilic 2,6‐Bis(1,2,3‐triazol‐4‐yl)pyridinePlatinum(II) Complexes: Synthesis, Characterization, Electrochemical, Photophysical, and Langmuir–Blodgett Film‐Formation Studies
Authors: Li Yongguang , Zhao Le , Tam Anthony Yiu‐Yan , Wong Keith Man‐Chung , Wu Lixin , Yam Vivian Wing‐Wah
Published: October 2013

A new series of platinum(II) complexes with tridentate ligands 2,6‐bis(1‐alkyl‐1,2,3‐triazol‐4‐yl)pyridine and 2,6‐bis(1‐aryl‐1,2,3‐triazol‐4‐yl)pyridine (N7R), [Pt(N7R)Cl]X (1–7) and [Pt(N7R)(CCR′)]X (8–17; R=n‐C4H9, n‐C8H17, n‐C12H25, n‐C14H29, n‐C18H37, C6H5, and CH2‐C6H5; R′=C6H5, C6H4‐CH3‐p, C6H4‐CF3‐p, C6H4‐N(CH3)2‐p, and cholesteryl 2‐propyn‐1‐yl carbonate; X=OTf−, PF6−, and Cl−), has been synthesized and characterized. Their electrochemical and photophysical properties have also been studied. Two amphiphilic platinum(II)2,6‐bis(1‐dodecyl‐1,2,3‐triazol‐4‐yl)pyridine complexes (3‐Cl and 8) were found to form stable and reproducible Langmuir–Blodgett (LB) films at the air/water interface. These LB films were characterized by the study of their surface‐pressure–molecular‐area (π–A) isotherms, XRD, and IR and polarized‐IR spectroscopy.
A Computational Study of the Mechanism of Hydrogen Evolution by Cobalt(Diimine‐Dioxime) Catalysts
Authors: Bhattacharjee Anirban , Andreiadis Eugen S. , Chavarot‐Kerlidou Murielle , Fontecave Marc , Field Martin J. , Artero Vincent
Published: October 2013

Cobalt(diimine‐dioxime) complexes catalyze hydrogen evolution with low overpotentials and remarkable stability. In this study, DFT calculations were used to investigate their catalytic mechanism, to demonstrate that the initial active state was a CoI complex and that H2 was evolved in a heterolytic manner through the protonation of a CoIIhydride intermediate. In addition, these catalysts were shown to adjust their electrocatalytic potential for hydrogen evolution to the pH value of the solution and such a property was assigned to the presence of a H+‐exchange site on the oxime bridge. It was possible to establish that protonation of the bridge was directly involved in the H2‐evolution mechanism through proton‐coupled electron‐transfer steps. A consistent mechanistic scheme is proposed that fits the experimentally determined electrocatalytic and electrochemical potentials of cobalt(diimine‐dioxime) complexes and reproduces the observed positive shift of the electrocatalytic potential with increasing acidity of the proton source.
DFT Study on the Recovery of Hoveyda–Grubbs‐Type Catalyst Precursors in Enyne and Diene Ring‐Closing Metathesis
Authors: Núñez‐Zarur Francisco , Solans‐Monfort Xavier , Pleixats Roser , Rodríguez‐Santiago Luis , Sodupe Mariona
Published: October 2013

DFT (B3LYP‐D) calculations have been used to better understand the origin of the recovered Hoveyda–Grubbs derivative catalysts after ring‐closing diene or enyne metathesis reactions. For that, we have considered the activation process of five different Hoveyda–Grubbs precursors in the reaction with models of usual diene and enyne reactants as well as the potential precursor regeneration through the release/return mechanism. The results show that, regardless of the nature of the initial precursor, the activation process needs to overcome relatively high energy barriers, which is in agreement with a relatively slow process. The precursor regeneration process is in all cases exergonic and it presents low energy barriers, particularly when compared to those of the activation process. This indicates that the precursor regeneration should always be feasible, unlike the moderate recoveries sometimes observed experimentally, which suggests that other competitive processes that hinder recovery should take place. Indeed, calculations presented in this work show that the reactions between the more abundant olefinic products and the active carbenes usually require lower energy barriers than those that regenerate the initial precatalyst, which could prevent precursor regeneration. On the other hand, varying the precursor concentration with time obtained from the computed energy barriers shows that, under the reaction conditions, the precursor activation is incomplete, thereby suggesting that the origin of the recovered catalyst probably arises from incomplete precursor activation.
Crystalline Supramolecular Nanofibers Based on Dehydrobenzoannulene Derivatives
Authors: Shigemitsu Hajime , Hisaki Ichiro , Kometani Eriko , Yasumiya Daisuke , Sakamoto Yuu , Osaka Keisuke , Thakur Tejender S. , Saeki Akinori , Seki Shu , Kimura Fumiko , Kimura Tsunehisa , Tohnai Norimitsu , Miyata Mikiji
Published: October 2013

Supramolecular nanofibers (SNFs) composed of low‐molecular‐weight π‐conjugated molecules exhibit attractive optical and electrical properties and are expected to be the next optoelectronic materials. In this work, five crystalline SNFs have been constructed from three dehydrobenzoannulene (DBA) derivatives. The DBAs were designed to assemble in one dimension in a strategy based on anisotropic crystal growth. The crystallinity of the SNFs allowed the molecular arrangements in the SNFs to be determined. Therefore the mechanism of construction and correlations between the molecular arrangements and optical and electrical properties could be considered. The results clearly indicate that the properties of the SNFs are affected by the chemical structures and molecular arrangements. Moreover, one of the SNFs exhibits a high charge‐carrier mobility (Σμ=0.61 cm2 V−1 s−1) because of its crystallinity and appropriate molecular arrangement. This systematic experimental study based on a proposed strategy has provided information for improving the electrical properties of SNFs. This strategy will lead to highly functional SNFs.
Mechanistic Intricacies of Gold‐Catalyzed Intermolecular Cycloadditions between Allenamides and Dienes
Authors: Montserrat Sergi , Faustino Hélio , Lledós Agustí , Mascareñas Jose L. , López Fernando , Ujaque Gregori
Published: October 2013

The mechanism of the gold‐catalyzed intermolecular cycloaddition between allenamides and 1,3‐dienes has been explored by means of a combined experimental and computational approach. The formation of the major [4+2] cycloaddition products can be explained by invoking different pathways, the preferred ones being determined by the nature of the diene (electron neutral vs. electron rich) and the type of the gold catalyst (AuCl vs. [IPrAu]+, IPr=1,3‐bis(2,6‐diisopropylphenyl)imidazole‐2‐ylidene). Therefore, in reactions catalyzed by AuCl, electron‐neutral dienes favor a concerted [4+3] cycloaddition followed by a ring contraction event, whereas electron‐rich dienes prefer a stepwise cationic pathway to give the same type of formal [4+2] products. On the other hand, the theoretical data suggest that by using a cationic gold catalyst, such as [IPrAuCl]/AgSbF6, the mechanism involves a direct [4+2] cycloaddition between the diene and the gold‐activated allenamide. The theoretical data are also consistent with the observed regioselectivity as well as with the high selectivity towards the formation of the enamide products with a Z configuration. Finally, our data also explain the formation of the minor [2+2] products that are obtained in certain cases.
Palladium‐Catalyzed Asymmetric Benzylation of Azlactones
Authors: Trost Barry M. , Czabaniuk Lara C.
Published: October 2013

Asymmetric benzylation of prochiral azlactone nucleophiles enables the catalytic introduction of a benzyl group towards the synthesis of α,α‐disubstituted amino acids. Herein, we report an enantioselective palladium‐catalyzed process using chiral bis(diphenylphosphinobenzoyl)diamine (dppba) ligands. Naphthalene‐ and heterocycle‐based methyl carbonates react with a number of azlactones derived from both natural and unnatural amino acids. Monocyclic benzylic electrophiles, for which the barrier to ionization is higher, must employ a phosphate leaving group in order to react. Reaction conditions for electron‐rich and ‐neutral benzylic electrophiles have been developed, and the scope of the reaction has been explored with respect to both reaction partners. The high levels of asymmetric induction, as well as the reactivity pattern of the electrophiles, suggest an η3‐benzyl intermediate that arises through two distinct pathways.
ChemInform Abstract: Effect of the Preparation Method on the Structural and Magnetic Properties of the Fe2Nb Alloy.
Authors: Velez G. Y. , Perez Alcazar G. A. , Zamora Ligia E. , Tabares J. A.
Published: October 2013

Fe2Nb alloy samples obtained by arc‐melting and mechanical alloying followed by heat treatment (700—925 K, 3—7 d) are characterized by XRD and Moessbauer spectroscopy.
ChemInform Abstract: Complex Long‐Range Magnetic Ordering in the Mn‐Bearing Dugganite Pb3TeMn3P2O14.
Authors: Silverstein H. J. , Sharma A. Z. , Cruz‐Kan K. , Zhou H. D. , Huq A. , Flacau R. , Wiebe C. R.
Published: October 2013

The title compound is prepared from a stoichiometric mixture of PbO, TeO2, MnO, and NH4H2PO4 (Al2O3 crucible, 400 °C for 12 h, 550 °C for 12 h, and 800 °C for 100 h).
ChemInform Abstract: Catalytic Use of Zinc Amide for Transmetalation with Allylboronates: General and Efficient Catalytic Allylation of Carbonyl Compounds, Imines, and Hydrazones.
Authors: Cui Yi , Li Wei , Sato Takehiro , Yamashita Yasuhiro , Kobayashi Shu
Published: October 2013

This highly efficient reaction for the allylation of a variety of carbonyl derivatives is the first synthetic method using catalytic amounts of a zinc amide.
ChemInform Abstract: Highly Selective Wacker Reaction of Styrene Derivatives: A Green and Efficient Aerobic Oxidative Process Promoted by Benzoquinone/NaNO2/HClO4 under Mild Conditions.
Authors: Zhang Guofu , Xie Xiaoqiang , Wang Yong , Wen Xin , Zhao Yun , Ding Chengrong
Published: October 2013

Vicinal disubstituted olefins are not suited as starting material.
ChemInform Abstract: Mesogenic 4‐Acryloyloxy‐ and 4‐(2,3‐Epoxypropoxy)phenyl 4‐Alkoxybenzoates.
Authors: Syrbu E. S. , Potemkina O. V. , Novikov I. V. , Kuvshinova S. A. , Koifman O. I. , Aleksandriiskii V. V. , Burmistrov V. A.
Published: October 2013

Products (III) and (V) exhibit the enantiotropic nematic mesomorphism in a sufficiently wide temperature range.
ChemInform Abstract: Asymmetric Dearomatizing Spirolactonization of Naphthols Catalyzed by Spirobiindane‐Based Chiral Hypervalent Iodine Species.
Authors: Dohi Toshifumi , Takenaga Naoko , Nakae Tomofumi , Toyoda Yosuke , Yamasaki Mikio , Shiro Motoo , Fujioka Hiromichi , Maruyama Akinobu , Kita Yasuyuki
Published: October 2013

Newly synthesized ortho‐functionalized spirobiindane‐based catalysts are used for the asymmetric title reaction.
ChemInform Abstract: Metal‐Controlled Cycloaddition of 2‐Alkynyl‐1,4‐benzoquinones and Styrenyl Systems: Lewis Acid versus π Acid.
Authors: Zhang Li , Li Zhiming , Fan Renhua
Published: October 2013

The regioselectivity of the cycloaddition results from the different activation modes of Bi(OTf)3 and AuCl (DFT calculations).
ChemInform Abstract: Preparation of Substituted Pyrroles via Ru(II)‐Catalyzed Coupling of Alkynes with Enamides.
Authors: Murugan Kaliyappan , Liu Shiuh‐Tzung
Published: October 2013

The optimized conditions can be used in DME or water.
ChemInform Abstract: Synthesis and Reactivity of Unsymmetrical Azomethine Imines Formed Using Alkene Aminocarbonylation.
Authors: Gan Wei , Moon Patrick J. , Clavette Christian , Das Neves Nicolas , Markiewicz Thomas , Toderian Amy B. , Beauchemin Andre M.
Published: October 2013

The title reaction provides a versatile approach to complex dipoles.
ChemInform Abstract: Catalyst‐Free and Stereoselective Synthesis of N,N‐Bicyclic Pyrazolidinone Derivatives.
Authors: Yang Desuo , Fan Mingjin , Zhu Haiyun , Guo Yaning , Guo Jiangtao
Published: October 2013

The 1,3‐dipolar cycloaddition of azomethine imines to nitroalkenes is investigated.
ChemInform Abstract: Design, Synthesis and Structure—Activity Relationships of 3,5‐Diaryl‐1H‐pyrazoles as Inhibitors of Arylamine N‐Acetyltransferase.
Authors: Fullam Elizabeth , Talbot James , Abuhammed Areej , Westwood Isaac , Davies Stephen G. , Russell Angela J. , Sim Edith
Published: October 2013

A series of pyrazole compounds (III) is synthesized.
ChemInform Abstract: Nef‐Isocyanide Adducts as Useful Synthons in a Novel Synthesis of Functionalized 5‐Imino‐2‐thioxothiazolidines.
Authors: Yavari Issa , Pashazadeh Ramin , Hosseinpour Reza , Ghanbari Ehsan
Published: October 2013

Potassium dithiocarbamates, prepared in situ, react with Nef‐isocyanide adducts to form the desired thiazole system in an efficient manner.
ChemInform Abstract: Studies on the Chemical Behavior of the Novel 6,8‐Dibromo‐7‐hydroxychromone‐3‐carboxaldehyde Towards Some Carbon Nucleophilic Reagents.
Authors: Ibrahim Magdy A. , Ali Tarik E. , El‐Kazak Azza M. , Mohamed Amira M.
Published: October 2013

The reactivity of the new aldehyde (III) towards some carbon nucleophiles is studied.
ChemInform Abstract: Triflic Anhydride Mediated Synthesis of Imidazo[1,5‐a]azines.
Authors: Pelletier Guillaume , Charette Andre B.
Published: October 2013

A wide range of imidazo[1,5‐a]azines is constructed using a mild cyclodehydration/aromatization reaction triggered by the use of triflic anhydride and 2‐methoxypyridine.
ChemInform Abstract: Synthesis of 2‐Amino‐imidazo[4,5‐b]pyridines.
Authors: Rosenberg Adam J. , Williams Theresa M. , Jordan Abraham J. , Clark Daniel A.
Published: October 2013

The presented approach is completely regioselective, procedurally simple, and provides rapid access to previously difficult to access moieties.
ChemInform Abstract: Supported N‐Propylsulfamic Acid on Magnetic Nanoparticles Used as Recoverable and Recyclable Catalyst for the Synthesis of 2,3‐Dihydroquinazolin‐4(1H)‐ones in Water.
Authors: Rostami Amin , Tahmasbi Bahman , Gholami Hoshyar , Taymorian Hajir
Published: October 2013

The magnetically recoverable catalyst promotes the reaction of anthranilic acid with aromatic aldehydes and aliphatic ketones.
ChemInform Abstract: One‐Pot Synthesis of Selenocarbamates from Isocyanates and Diselenides Using the Zn/AlCl3 System.
Authors: Movassagh Barahman , Moradi Mona
Published: October 2013

The process is advantageous with regards to operational simplicity, mild conditions and high reaction rate.
ChemInform Abstract: Synthesis of Functionalized Diketopiperazines as Cyclotryprostatin and Tryprostatin Analogues.
Authors: Nguyen Van Tuyen , Claes Pieter , De Kimpe Norbert
Published: October 2013

Reaction of L‐tryptophan ethyl ester (I) with aromatic aldehydes gives a separable mixture of diastereomers (III) and (IV).
ChemInform Abstract: Composition Dependent Elastic Modulus and Phase Stability of Ni2MnGa Based Ferromagnetic Shape Memory Alloys
Authors: Hu Qing Miao , Luo Hu Bin , Li Chun Mei , Vitos Levente , Yang Rui
Published: October 2013

Review: 58 refs.
ChemInform Abstract: Organic Stereochemistry. Part 5. Stereoselectivity in Molecular and Clinical Pharmacology
Authors: Testa Bernard , Vistoli Giulio , Pedretti Alessandro , Caldwell John
Published: October 2013

Review: 169 refs.
ChemInform Abstract: Use of Sulfur Fragments for the Synthesis of Nitrogen Heterocycles
Authors: Padwa Albert
Published: October 2013

Review: 178 refs.
ChemInform Abstract: Aziridinyl Imines in Organic Synthesis: Development of Tandem Reaction Strategies and Application to Total Synthesis of Natural Products
Authors: Lee Hee‐Yoon , Song Seog‐Beom , Kang Taek , Kim Yoon Jung , Geum Su Jeong
Published: October 2013

Review: 37 refs.
ChemInform Abstract: Synthetically Derived Auxiliaries: Organometallic Derivatives (Main Group and Transition Metals)
Authors: Moyano A.
Published: October 2013

Review: 94 refs.
ChemInform Abstract: Layered Double Hydroxide‐Based Catalysts: Nanostructure Design and Catalytic Performance
Authors: He Shan , An Zhe , Wei Min , Evans David G. , Duan Xue
Published: October 2013

Review: 99 refs.
ChemInform Abstract: Higher‐Order Multicomponent Reactions: Beyond Four Reactants
Authors: Brauch Sebastian , van Berkel Sander S. , Westermann Bernhard
Published: October 2013

Review: 55 refs.
ChemInform Abstract: Inverse Electron Demand Diels—Alder (iEDDA)‐Initiated Conjugation: A (High) Potential Click Chemistry Scheme
Authors: Knall Astrid‐Caroline , Slugovc Christian
Published: October 2013

Review: 49 refs.
ChemInform Abstract: Solid‐Emissive BODIPY Derivatives: Design, Synthesis and Applications
Authors: Xiao Shuzhang , Cao Qiong , Dan Feijun
Published: October 2013

Review: 91 refs.
ChemInform Abstract: Near‐Infrared Phosphorescence: Materials and Applications
Authors: Xiang Haifeng , Cheng Jinghui , Ma Xiaofeng , Zhou Xiangge , Chruma Jason Joseph
Published: October 2013

Review: 482 refs.
ChemInform Abstract: Glycosidase Inhibitors: Versatile Tools in Glycobiology
Authors: Lopez Oscar , Merino‐Montiel Penelope , Martos Sergio , Gonzalez‐Benjumea Alejandro
Published: October 2013

Review: 164 refs.
ChemInform Abstract: Synthesis and Utilization of Sugar Compounds Derived from Lignocellulosic Biomass
Authors: Kobayashi Hirokazu , Fukuoka Atsushi
Published: October 2013

Review: < 230 refs.
ChemInform Abstract: Nanomaterials Based Electrochemical Sensors for Biomedical Applications
Authors: Chen Aicheng , Chatterjee Sanghamitra
Published: October 2013

Review: 80 refs.
ChemInform Abstract: Computational Enzyme Design
Authors: Kiss Gert , Celebi‐Oelcuem Nihan , Moretti Rocco , Baker David , Houk K. N.
Published: October 2013

Review: 213 refs.
ChemInform Abstract: Convective Assembly of Patterned Media
Authors: Ghosh Moniraj , Stebe Kathleen J.
Published: October 2013

Review: 319 refs.
ChemInform Abstract: Applications of Derivatization Reactions to Trace Organic Compounds During Sample Preparation Based on Pressurized Liquid Extraction
Authors: Carro Antonia M. , Gonzalez Paula , Lorenzo Rosa A.
Published: October 2013

Review: 57 refs.
ChemInform Abstract: Lithium Chalcogenidotetrelates: LiChT—Synthesis and Characterization of New Li+ Ion Conducting Li/Sn/Se Compounds.
Authors: Kaib Thomas , Bron Philipp , Haddadpour Sima , Mayrhofer Leonhard , Pastewka Lars , Jaervi Tommi T. , Moseler Michael , Roling Bernhard , Dehnen Stefanie
Published: October 2013

The new compounds (IV)—(VIII) are characterized by single crystal XRD and impedance spectroscopy.
ChemInform Abstract: Catalytic Activity of Palladium(II) Diaminocarbene Complexes in the Sonogashira and Suzuki Reactions.
Authors: Mikhailov V. N. , Savicheva E. A. , Sorokoumov V. N. , Boyarskii V. P.
Published: October 2013

Cross‐coupling reactions of haloarenes with oct‐1‐yne (Sonogashira reaction) and phenylboronic acid (Suzuki reaction) are presented using palladium(II) complexes with chelating and non‐chelating diaminocarbene ligands as catalysts.
ChemInform Abstract: Selective Reduction of Acyl Aziridines to Mannich Bases Using Silyllithium Reagents.
Authors: Davis Amanda L. , Korous Arthur A. , Hartel Aaron M.
Published: October 2013

The selective α‐reduction of N‐protected acyl aziridines is achieved with methyldiphenylsilyllithium in THF to produce Mannich bases.
ChemInform Abstract: Enantioselective Synthesis of 3‐Hydroxytetradecanoic Acid and Its Methyl Ester Enantiomers as New Antioxidants and Enzyme Inhibitors.
Authors: Kuecuek Hatice Baspinar , Yusufoglu Ayse
Published: October 2013

Racemic ester (I) is resolved into optically pure enantiomers by porcine pancreas lipase catalyzed hydrolysis of (‐)‐enantiomer followed by column chromatographic separation.
ChemInform Abstract: Multistep Synthesis of Amides from Alcohols and Amines in Continuous Flow Microreactor Systems Using Oxygen and Urea Hydrogen Peroxide as Oxidants.
Authors: Liu Xiaoying , Jensen Klavs F.
Published: October 2013

The oxidation of alcohols (I) in a packed‐bed microreactor followed by oxidative amidation of resulting aldehydes with amines (II) in a spiral‐channel microreactor leads to a wide range of amides (III).
ChemInform Abstract: Stereo‐Controlled Deamination of Ketoaziridines Using Ph3P/I2.
Authors: Samimi Heshmat Allah , Kiyani Hamzeh , Shams Zahra
Published: October 2013

A novel and efficient method for the deamination of N‐H and N‐alkyl aziridines using Ph3P·I2 is developed.
ChemInform Abstract: Duality of Donor—Acceptor Cyclopropane Reactivity as a Three‐Carbon Component in Five‐Membered Ring Construction: [3 + 2] Annulation versus [3 + 2] Cycloaddition.
Authors: Volkova Yulia A. , Budynina Ekaterina M. , Kaplun Alexey E. , Ivanova Olga A. , Chagarovskiy Alexey O. , Skvortsov Dmitriy A. , Rybakov Victor B. , Trushkov Igor V. , Melnikov Mikhail Ya.
Published: October 2013

A new simple approach to the synthesis of cyclopentannulated (hetero)arenes is developed.
ChemInform Abstract: Control of Remote Stereochemistry in the Synthesis of Spirocyclic Oxindoles: Vinylogous Organocascade Catalysis.
Authors: Tian Xu , Melchiorre Paolo
Published: October 2013

The ability of the cinchona derived bifunctional catalyst to propagate the aminocatalytic activation modes through the conjugated π‐system of substrates (I) while transmitting the stereochemical information to distant positions renders possible the synthesis of spiro compounds (III) and (V) with high diastereo‐ and enantioselectivity.
ChemInform Abstract: Cinchona Alkaloid Amide/Copper(II) Catalyzed Diastereo‐ and Enantioselective Vinylogous Mannich Reaction of Ketimines with Siloxyfurans.
Authors: Hayashi Masashi , Sano Masahide , Funahashi Yasuhiro , Nakamura Shuichi
Published: October 2013

The asymmetric vinylogous Mannich reaction of unactivated ketimines with siloxyfurans using cinchona alkaloids and Cu(OAc)2 as catalysts is reported.
ChemInform Abstract: CuBr‐Catalyzed Cascade Reaction of 2‐Substituted‐3‐(1‐alkynyl)chromones to Synthesize Functionalized 3‐Acylfurans.
Authors: Huang Liping , Hu Feng , Ma Qingdong , Hu Youhong
Published: October 2013

The cascade involves 1,4‐addition, cyclization and hydrolysis to provide various multisubstituted 3‐acylfurans in a convenient manner.