bluuebunny/crossref_metadata_2025 huggingface dataset:
Évolution des connaissances sur les gangs de rue. Nouveau regard sur les jeunes qui s’y joignent
Authors: Hamel1 Sylvie , Alain Marc , Messier-Newman Karine
Published: November 2015

Cet article fait état des connaissances nouvelles sur lephénomène des gangs de rue découlant d’unerecension critique de la littérature scientifique sur le sujet.Cette recension se concentre sur des articles parus après 1997,soit après la publication d’une première recensionsur le sujet au Québec. En exerçant certains comparatifsentre les deux recensions, il apparaît non seulement que lesconnaissances se sont beaucoup développées sur certainsplans, mais que la manière d’aborder la complexitédu problème s’est littéralement transformée.Dans le cadre de cet article, nous traitons spécifiquement desprocessus de l’engagement et du désistement, de laviolence des gangs et des caractéristiques internes des jeunesqui s’y joignent, soit là où cette transformationest particulièrement saisissante. En terminant, nous proposonsquelques pistes de réflexion sur les incidences possibles surl’intervention auprès des jeunes qui fontl’expérience de ces groupes.
Définition des gangs et identification des membres à des fins policières1
Authors: Guay2 Jean-Pierre , Fredette Chantal , Mercier Marc-André , Dubé Nathalie , Hobbs Julie , Paixao James , Brisebois René-André
Published: November 2015

L’exercice qui vise à définir les gangs de rue et à en identifier les membres est complexe. Plusieurs caractéristiques de ces groupes, notamment leur caractère élusif et clandestin, leur grande hétérogénéité ainsi que leur caractère changeant nous ont poussés à en modifier notre conceptualisation. Cet article propose une définition générale et simple qui décrit le gang de rue comme un groupe criminel organisé qui se distingue des autres groupes du crime organisé définis par la loi 467.1. L’accent est toutefois mis sur le caractère opérationnel des marqueurs d’appartenance et le rationnel qui sous-tend leur développement. Une nouvelle définition des gangs jumelée à une opérationnalisation basée sur des critères observables par les organisations policières offre plusieurs avantages par rapport à une définition développée dans un cadre académique. Les implications théoriques et les enjeux pratiques sont également abordés.
Les jeunes en bande et leurs parents. Les ressorts symboliques du détachement
Authors: Mohammed1 Marwan
Published: November 2015

L’analyse du rôle des familles dans la formation des bandes de jeunes est l’objet d’un certain paradoxe. Le fonctionnement intrafamilial est davantage commenté, déduit, que directement observé en situation. Paradoxe qui rejaillit sur les interventions institutionnelles de plus en plus intrusives et contraignantes. L’une des explications réside sans doute dans les choix méthodologiques. La prédominance des approches statistiques a tendance à occulter des processus microsociologiques nichés dans les plis intimes des relations et de la symbolique familiales qui nécessitent des dispositifs d’observation ancrés. C’est l’objet de cet article qui vise à mettre en perspective le poids des représentations et des jugements moraux réciproques entre les jeunes en bande et leurs parents. Des analyses qui proposent de remettre en question, voire de renouveler, la manière dont la recherche s’interroge sur les facteurs familiaux de la délinquance juvénile, en particulier le phénomène des bandes de jeunes, et les théorise.
La reconnaissance émotionnelle faciale : validation préliminaire de stimuli virtuels dynamiques et comparaison avec les Pictures of Facial Affect (POFA)
Authors: Cigna1 Marie-Hélène , Guay Jean-Pierre , Renaud Patrice
Published: November 2015

Bien que des photographies d’expressions émotionnelles faciales soient couramment utilisées pour étudier le traitement des informations affectives, les ensembles de stimuli actuels comportent différentes limites méthodologiques. Dans la perspective d’améliorer la validité écologique des travaux sur la reconnaissance émotionnelle faciale (REF), l’étude propose un nouvel ensemble de stimuli dynamiques constitué de personnages virtuels exprimant les six émotions fondamentales à différentes intensités. La validation préliminaire des stimuli a été effectuée en les comparant aux stimuli du POFA. Dans l’étude 1, le contenu émotionnel de 84 avatars statiques et de 48 photographies du POFA a été évalué par 150 étudiants. Dans l’étude 2, la REF a été évaluée chez 134 étudiants à l’aide d’avatars dynamiques. L’habileté à reconnaître les émotions est similaire à celle rapportée dans la littérature scientifique ainsi qu’au POFA. Les résultats permettent de conclure que les avatars constituent un ensemble valide de stimuli pour étudier la REF, offrant une contribution significative dans le domaine de la recherche émotionnelle. L’usage d’avatars étant de plus en plus courant à des fins d’intervention et de recherche, les stimuli ouvrent aussi la voie à diverses applications, entre autres pour l’étude des comportements violents. D’autres travaux devront être réalisés afin de poursuivre leur validation.
New craniodental remains ofWakaleo alcootaensis(Diprotodontia: Thylacoleonidae) a carnivorous marsupial from the late Miocene Alcoota Local Fauna of the Northern Territory, Australia
Authors: Yates Adam M.
Published: November 2015

New jaws and teeth referable to the rare thylacoleonid marsupialWakaleo alcootaensisare figured and described. The species is the geologically youngest known member of the genus and is only known from the late Miocene Alcoota Local Fauna of the Northern Territory, Australia. A revised diagnosis of the species is presented which is found to be morphologically distinct from its congeners.W. alcootaensiscan be distinguished from other species ofWakaleoby its greater size, deeply recessed masseteric fossa, more steeply angled I1, loss of P2, greater P3to M1ratio and loss of M3. Several characters ofW. alcootaensis, including the increase in size, steeply angled I1, increase of the relative size of P3, and reduction of the molar row are present in at least some species ofThylacoleo. Phylogenetic analysis suggests that these character states are convergences and that there was parallel evolution in these two thylacoleonid lineages.
The role of dynamic surface water‐groundwater exchange on streambed denitrification in a first‐order, low‐relief agricultural watershed
Authors: Rahimi Mina , Essaid Hedeff I. , Wilson John T.
Published: November 2015

The role of temporally varying surface water‐groundwater (SW‐GW) exchange on nitrate removal by streambed denitrification was examined along a reach of Leary Weber Ditch (LWD), Indiana, a small, first‐order, low‐relief agricultural watershed within the Upper Mississippi River basin, using data collected in 2004 and 2005. Stream stage, GW heads (H), and temperatures (T) were continuously monitored in streambed piezometers and stream bank wells for two transects across LWD accompanied by synoptic measurements of stream stage, H, T, and nitrate (NO3) concentrations along the reach. The H and T data were used to develop and calibrate vertical two‐dimensional, models of streambed water flow and heat transport across and along the axis of the stream. Model‐estimated SW‐GW exchange varied seasonally and in response to high‐streamflow events due to dynamic interactions between SW stage and GW H. Comparison of 2004 and 2005 conditions showed that small changes in precipitation amount and intensity, evapotranspiration, and/or nearby GW levels within a low‐relief watershed can readily impact SW‐GW interactions. The calibrated LWD flow models and observed stream and streambed NO3 concentrations were used to predict temporal variations in streambed NO3 removal in response to dynamic SW‐GW exchange. NO3 removal rates underwent slow seasonal changes, but also underwent rapid changes in response to high‐flow events. These findings suggest that increased temporal variability of SW‐GW exchange in low‐order, low‐relief watersheds may be a factor contributing their more efficient removal of NO3.
Spatial slip behavior of large strike‐slip fault belts: Implications for the Holocene slip rates of the eastern termination of the North Anatolian Fault, Turkey
Authors: Zabcı Cengiz , Sançar Taylan , Akyüz H. Serdar , Kıyak Nafiye Güneç
Published: November 2015

We present new data on Holocene slip rates for the eastern end of the North Anatolian Fault (NAF) by using the optically stimulated luminescence ages of the offset terrace deposits at two sites, where a total of four displaced landforms was studied. Each offset feature was analyzed independently, and three different assumptions were made for all the offsets, depending on whether the age of the upper tread (upper tread reconstruction), the lower tread (lower tread reconstruction), or all bounding surfaces (intermediate solution) were used in dating of the terrace risers. The deflected geometry of the risers strongly suggests the use of either the intermediate solution or the upper tread reconstruction. The joint slip rate distributions for the upper tread reconstructions and the intermediate solutions were modeled as 13.0 + 1.8 / −1.4 and 14.3 + 5.8 / −2.4 mm/yr (2σ), respectively. Although the intermediate solution covers the full range of ages for the measured displacements, the curved geometry of the terrace risers suggests that the initiations of the riser offsets are most probably close to the abandonment ages of the upper terrace treads. Therefore, we accepted the joint slip rate of the intermediate solution but suggested that the average rate for the main displacement zone of the eastern NAF should be close to its lower limits. This slower rate with respect to previous estimates suggests that the total deformation is not only accommodated on the main displacement zone but is also distributed along the secondary faults to the south of the easternmost segments of the NAF.
Quantifying slip balance in the earthquake cycle: Coseismic slip model constrained by interseismic coupling
Authors: Wang Lifeng , Hainzl Sebastian , Mai P. Martin
Published: November 2015

The long‐term slip on faults has to follow, on average, the plate motion, while slip deficit is accumulated over shorter timescales (e.g., between the large earthquakes). Accumulated slip deficits eventually have to be released by earthquakes and aseismic processes. In this study, we propose a new inversion approach for coseismic slip, taking interseismic slip deficit as prior information. We assume a linear correlation between coseismic slip and interseismic slip deficit and invert for the coefficients that link the coseismic displacements to the required strain accumulation time and seismic release level of the earthquake. We apply our approach to the 2011M9 Tohoku‐Oki earthquake and the 2004M6 Parkfield earthquake. Under the assumption that the largest slip almost fully releases the local strain (as indicated by borehole measurements), our results suggest that the strain accumulated along the Tohoku‐Oki earthquake segment has been almost fully released during the 2011M9 rupture. The remaining slip deficit can be attributed to the postseismic processes. Similar conclusions can be drawn for the 2004M6 Parkfield earthquake. We also estimate the required time of strain accumulation for the 2004M6 Parkfield earthquake to be ~25 years (confidence interval of [17, 43] years), consistent with the observed average recurrence time of ~22 years forM6 earthquakes in Parkfield. For the Tohoku‐Oki earthquake, we estimate the recurrence time of ~500–700 years. This new inversion approach for evaluating slip balance can be generally applied to any earthquake for which dense geodetic measurements are available.
Conjugate rifted margins width and asymmetry: The interplay between lithospheric strength and thermomechanical processes
Authors: Svartman Dias Anna Eliza , Lavier Luc L. , Hayman Nicholas W.
Published: November 2015

Numerical experiments have been used to relate the range in the distribution and the style of deformation observed in rifted margins to localizing/delocalizing thermomechanical processes. The experiments give rise to four end‐members of margins for varying initial lithospheric strength and extension rates. The first two end‐members are narrow and asymmetric and narrow and near‐symmetric, conjugate margins. The third end‐member is asymmetric conjugate margins, wherein one side is <100 km wide and the other is >100–300 km wide. Lastly, we explore wide rift systems that may form very asymmetric conjugate margins with one narrow margin and a very wide conjugate, 200 km to > 350 km across. With initial and boundary conditions close to that inferred from the North and South Atlantic margins, we find that not all margins experience a polyphase rifting history of stretching‐thinning‐exhumation. Instead, the stretching mode can be very short or protracted, and the thinning or the exhumation modes can be incomplete or absent. The deformation localization of the thinning mode is in places associated with the formation of a keystone block or “block H.” A new mechanism for the formation of the unstable crustal root under block H is described, wherein the bounding border faults lead to differential thinning of the crust and mantle lithosphere. Nonuniform extension also occurs in both types of wide rift systems and is related to the sequential deformation migration outward of an initial graben, associated with effective lithospheric strengthening that occurs during crustal thinning and bending.
Experimental constraints on the role of dynamic recrystallization on resetting the Ti‐in‐quartz thermobarometer
Authors: Nachlas W. O. , Hirth G.
Published: November 2015

We conducted deformation experiments on Ti‐doped quartz aggregates to investigate the effect of crystal‐plastic deformation and dynamic recrystallization on Ti substitution in quartz. Shear experiments were conducted at 1.0 GPa and 900°C at a constant shear strain rate (~5 × 10−6 s−1) for progressively longer intervals of time (24, 48, and 72 h). Equivalent experiments were conducted under hydrostatic stress to compare the effect of deformation relative to static crystallization. A novel quartz‐doping technique is used to synthesize a quartz aggregate consisting of two layers with Ti concentrations above and below the predicted solubility level for the experimental conditions. Samples deformed to progressively higher shear strain by dislocation creep accommodated by a combination of subgrain rotation and grain boundary migration recrystallization show a strengthening of the crystallographic preferred orientation that correlates with a progressive evolution of Ti concentrations. Quartz grains in the highest strain, most strongly recrystallized samples have Ti concentrations that are most similar to undeformed quartz grown in hydrostatic annealing experiments. Cathodoluminescence (CL) analysis of intragrain variations in Ti content reveals core and rim zoning present in the starting material that becomes progressively homogenized with increasing strain—recrystallized quartz in the highest‐strain samples exhibits a uniform CL signal. We conclude that dynamic recrystallization enhances the kinetics of trace element equilibration in quartz, illustrating that Ti‐in‐quartz thermobarometry is capable of recording the conditions of ductile shearing.
Derivation of operation rules for reservoirs in parallel with joint water demand
Authors: Zeng Xiang , Hu Tiesong , Xiong Lihua , Cao Zhixian , Xu Chongyu
Published: November 2015

The purpose of this paper is to derive the general optimality conditions of the commonly used operating policies for reservoirs in parallel with joint water demand, which are defined in terms of system‐wide release rules and individual reservoir storage balancing functions. Following that, a new set of release rules for individual reservoirs are proposed in analytical forms by considering the optimality conditions for the balance of total water delivery utility and carryover storage value of individual reservoirs. Theoretical analysis indicates that the commonly used operating policies are a special case of the newly derived rules. The derived release rules are then applied to simulating the operation of a parallel reservoir system in northeastern China. Compared to the performance of the commonly used policies, some advantages of the proposed operation rules are illustrated. Most notably, less water shortage occurrence and higher water supply reliability are obtained from the proposed operation rules.
Complementary‐relationship‐based 30 year normals (1981–2010) of monthly latent heat fluxes across the contiguous United States
Authors: Szilagyi Jozsef
Published: November 2015

Thirty year normal (1981–2010) monthly latent heat fluxes (ET) over the conterminous United States were estimated by a modified Advection‐Aridity model from North American Regional Reanalysis (NARR) radiation and wind as well as Parameter‐Elevation Regressions on Independent Slopes Model (PRISM) air and dew‐point temperature data. Mean annual ET values were calibrated with PRISM precipitation (P) and validated against United States Geological Survey runoff (Q) data. At the six‐digit Hydrologic Unit Code level (sample size of 334) the estimated 30 year normal runoff (P – ET) had a bias of 18 mm yr−1, a root‐mean‐square error of 96 mm yr−1, and a linear correlation coefficient value of 0.95, making the estimates on par with the latest Land Surface Model results but without the need for soil and vegetation information or any soil moisture budgeting.
Surgical treatment of gastrointestinal hereditary hemorrhagic telangiectasia
Authors: Yen Min‐Hsuan , Chen Chiung‐Nien
Published: November 2015

Case

A 48‐year‐old man with a history of gastrointestinal bleeding from Osler–Weber–Rendu disease presented with recurrent hematemesis and tarry stool. He received repeated endoscopic therapy, but profound component therapy was still needed. Because repeated gastrointestinal bleeding was caused by same bleeder, tattoo‐assisted laparoscopic gastric wedge resection was carried out.

Outcome

The pathology showed vascular abnormalities that involved gastric mucosal and submucosal layers. After surgery, the blood transfusion for the patient is not seen.

Conclusion

Osler–Weber–Rendu is a hereditary disease characterized by vascular abnormalities of the nose, skin, lung, brain, and gastrointestinal tract. Management of gastrointestinal bleeding requires medical treatment first, and there are rare reports of surgical treatment. Our pathology findings showed a transmucosal vessel lesion, which had poor response to endoscopic treatment. Surgical intervention may be considered in the patient with gastrointestinal bleeding refractory to endoscopic therapy.
Thermal and dielectric properties of electrospun fiber membranes from polyimides with different structural units
Authors: Li Penggang , Liu Leipeng , Ding Ling , Lv Fengzhu , Zhang Yihe
Published: November 2015

In this work, electrospinning technique was used to prepare low dielectric constant membranes. First, three kinds of polyimide (PI) fiber membranes were fabricated by electrospinning of poly(amic acid) (PAA) solutions which are from polycondensation of 4,4′‐oxidianiline (ODA) and three dianhydrides, pyromellitic dianhydride (PMDA), 2,2′‐bis(3,4‐dicarboxyphenyl) hexafluropropane dianhydride (6FDA) and 1,2,4,5‐cyclohexanetetracarboxylic dianhydride(HPMDA), followed by imidization at higher temperature. The relationship of the fiber morphology, thermostability and dielectric properties of the membranes with the polymer structure were discussed. Under the same conditions, PAAs with more flexible structure are easier to form low viscosity solution and fabricate high pore fraction membranes which are low dielectric constant materials. Under the coupling effect of fluorine‐containing groups and contribution of pores, the dielectric constant of 6FDA‐containing PI is lowered to 1.21 at 1 KHz with lower dielectric loss which accords with the calculated one. Also the 5% weight loss temperature of the three kinds of PIs is all higher than 400°C. The formed electrospun membranes are thermostable low dielectric constant materials. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43081.
Effects of PEMF on patients with osteoarthritis: Results of a prospective, placebo‐controlled, double‐blind study
Authors: Wuschech Heinz , von Hehn Ulrike , Mikus Eberhard , Funk Richard H.
Published: November 2015

This study aimed to evaluate effects of pulsed electromagnetic fields (PEMF) in a double blind study on patients with knee joint osteoarthritis. The MAGCELL ARTHRO electrode‐less therapy delivered a sinusoidal magnetic field, varying in frequency between 4 and 12 Hz. In 1 cm tissue depth, magnetic flux density was 105 mT. A total of n = 57 patients were randomly assigned to the verum, PEMF or placebo group (placebo device). Their average age was 61.6 ± 12.0 years. According to American College of Rheumatology criteria the osteoarthritis level was 2.8 ± 0.8. Treatment was performed twice a day for 5 min over a period of 18 days. Treatment with the MAGCELL device versus control (sham exposed) showed a highly significant reduction in pain (P < 0.001), a significant reduction in stiffness (P = 0.032) and a significant reduction in disability in daily activities (P = 0.005) according to the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scales—with a good overall treatment tolerance. In the placebo group there was no evidence of a significant change between the initial and final examination in any of the three above‐mentioned WOMAC scales. Results of this partly randomized placebo‐controlled double‐blind study show clinically at any rate, that use of PEMF lead to highly significant better results in the treatment group compared to the placebo group with regard to the total WOMAC global score and especially for visual analogue scale. Patient assessment of the “effectiveness” was rated in 29.5% as very good and good in 27.3% compared to 0.0% and 15.4% in controls. This therapy is thus a useful complementary treatment option with no side effects. Bioelectromagnetics. 36:576–585, 2015. © 2015 Wiley Periodicals, Inc.
Identification of vanishing tophi by three‐dimensional dual‐energy computed tomography in a patient with chronic tophaceous gout
Authors: Jung Seung Min , Ju Ji Hyeon
Published: November 2015

Key clinical message

Large gout tophi are difficult to treat and sometimes needs operation for its elimination. Dual‐energy computed tomography (DECT) is now being used for detection of tophi in patients with gouty arthritis. After intensive treatment, we could observe vanishing tophi with DECT.
The Effect of Additives on the High‐Temperature Stability of the Vanadium Redox Flow Battery Positive Electrolytes
Authors: Kausar Nadeem , Mousa Asem , Skyllas‐Kazacos Maria
Published: November 2015

Several inorganic additives are investigated as potential precipitation inhibitors for the positive half‐cell electrolyte of the vanadium redox flow battery (VRB) at elevated temperatures. Electrolyte stability tests on the more concentrated 2 m vanadium electrolyte show that of the additives tested, the best results are obtained with the addition of 1 % phosphoric acid that give induction times of 40, 22 and 18 days for 80, 90 and 95 % state of charge (SOC) solutions at 50 °C, compared with 5, 2 and 1 days respectively for the corresponding blank solution. Several additives are also evaluated at 45 °C in a vanadium redox flow cell operating with a 2 m vanadium electrolyte. In the case of the cell employing the blank solution, a sudden drop in capacity, followed by pump failure is observed after around 70 cycles, while the cells with the additives continue to cycle without failure for 120 and 150 cycles for ammonium sulphate and ammonium phosphate additives respectively. A similar stabilising effect has previously been observed with these additives at low temperatures in the negative half‐cell electrolyte of the VRB, confirming that these stabilising agents have the potential to extend the upper and lower operating temperature limits of a 2 m vanadium electrolyte in the VRB to 45 and 5 °C respectively, while also significantly enhancing its energy density without the need for potentially hazardous chloride additions.
Water Oxidation for Simplified Models of the Oxygen‐Evolving Complex in Photosystem II
Authors: Li Xichen , Siegbahn Per E. M.
Published: November 2015

For the main parts of the mechanism for water oxidation in photosystem II there has recently been very strong experimental support for the mechanism suggested by theoretical model studies. The question addressed in the present study is to what extent this knowledge can be used for the design of artificial catalysts. A major requirement for a useful artificial catalyst is that it is small enough to be synthesized. Small catalysts also have the big advantage that they could improve the catalysis per surface area. To make the mechanism found for PSII useful in this context, it needs to be analyzed in detail. A small model system was therefore used and the ligands were replaced one by one by water‐derived ligands. Only the main chemical step of OO bond formation was investigated in this initial study. The energetics for this small model and the larger one previously used for PSII are remarkably similar, which is the most important result of the present study. This shows that small model complexes have a potential for being very good water oxidation catalysts. It was furthermore found that there is a clear correlation between the barrier height for OO bond formation and the type of optimal structure for the S3 state. The analysis shows that a flexible central part of the complex is the key for efficient water oxidation.
σ Aromaticity Dominates in the Unsaturated Three‐Membered Ring of Cyclopropametallapentalenes from Groups 7–9: A DFT Study
Authors: Hao Yulei , Wu Jingjing , Zhu Jun
Published: November 2015

Aromaticity, an old but still fantastic topic, has long attracted considerable interest of chemists. Generally, π aromaticity is described by π‐electron delocalization in closed circuits of unsaturated compounds whereas σ‐electron delocalization in saturated rings leads to σ aromaticity. Interestingly, our recent study shows that σ aromaticity can be dominating in an unsaturated three‐membered ring (3MR) of cyclopropaosmapentalene. An interesting question is raised: Can the σ aromaticity, which is dominant in the unsaturated 3MR, be extended to other cyclopropametallapentalenes? If so, how could the metal centers, ligands, and substituents affect the σ aromaticity? Here, we report a thorough theoretical study on these issues. The nucleus‐independent chemical shift calculations and the anisotropy of the current‐induced density plots reveal the dominant σ aromaticity in these unsaturated 3MRs. In addition, our calculations show that substituents on the 3MRs have significant effects on the σ aromaticity, whereas the ligand effect is particularly small.
Superior Photostability and Photocatalytic Activity of ZnO Nanoparticles Coated with Ultrathin TiO2 Layers through Atomic‐Layer Deposition
Authors: Sridharan Kishore , Jang Eunyong , Park Young Min , Park Tae Joo
Published: November 2015

Atomic‐layer deposition (ALD) is a thin‐film growth technology that allows for conformal growth of thin films with atomic‐level control over their thickness. Although ALD is successful in the semiconductor manufacturing industry, its feasibility for nanoparticle coating has been less explored. Herein, the ALD coating of TiO2 layers on ZnO nanoparticles by employing a specialized rotary reactor is demonstrated. The photocatalytic activity and photostability of ZnO nanoparticles coated with TiO2 layers by ALD and chemical methods were examined by the photodegradation of Rhodamine B dye under UV irradiation. Even though the photocatalytic activity of the presynthesized ZnO nanoparticles is higher than that of commercial P25 TiO2 nanoparticles, their activity tends to decline due to severe photocorrosion. The chemically synthesized TiO2 coating layer on ZnO resulted in severely declined photoactivity despite the improved photostability. However, ultrathin and conformal ALD TiO2 coatings (≈0.75–1.5 nm) on ZnO improved its photostability without degradation of photocatalytic activity. Surprisingly, the photostability is comparable to that of pure TiO2, and the photocatalytic activity to that of pure ZnO.
Palladium(0)/NHC‐Catalyzed Reductive Heck Reaction of Enones: A Detailed Mechanistic Study
Authors: Raoufmoghaddam Saeed , Mannathan Subramaniyan , Minnaard Adriaan J. , de Vries Johannes G. , Reek Joost N. H.
Published: November 2015

We have studied the mechanism of the palladium‐catalyzed reductive Heck reaction ofpara‐substituted enones with 4‐iodoanisole by usingN,N‐diisopropylethylamine (DIPEA) as the reductant. Kinetic studies and in situ spectroscopic analysis have provided a detailed insight into the reaction. Progress kinetic analysis demonstrated that neither catalyst decomposition nor product inhibition occurred during the catalysis. The reaction is first order in the palladium and aryl iodide, and zero order in the activated alkene, N‐heterocyclic carbene (NHC) ligand, and DIPEA. The experiments with deuterated solvent ([D7]DMF) and deuterated base ([D15]Et3N) supported the role of the amine as a reductant in the reaction. The palladium complex [Pd0(NHC)(1)] has been identified as the resting state. The kinetic experiments by stopped‐flow UV/Vis also revealed that the presence of the second substrate, benzylideneacetone1, slows down the oxidative addition of 4‐iodoanisole through its competing coordination to the palladium center. The kinetic and mechanistic studies indicated that the oxidative addition of the aryl iodide is the rate‐determining step. Various scenarios for the oxidative addition step have been analyzed by using DFT calculations (bp86/def2‐TZVP) that supported the inhibiting effect of substrate1by formation of resting state [Pd0(NHC)(1)] species at the cost of further increase in the energy barrier of the oxidative addition step.
Cyano‐Schmittel Cyclization through Base‐Induced Propargyl‐Allenyl Isomerization: Highly Modular Synthesis of Pyridine‐Fused Aromatic Derivatives
Authors: You Xu , Xie Xin , Chen Haoyi , Li Yuxue , Liu Yuanhong
Published: November 2015

The cyano‐Schmittel cyclization of in situ‐generated cyano‐allenes has been carried out. The DFT calculation results suggest that the diradical pathway plays a major role in this cyclization. The reactions can be conveniently performed in a one‐pot manner through cascade Sonogashira coupling of terminal cyano‐ynes with organic halides, followed by base‐promoted propargyl‐allenyl isomerization/cyclization, leading to an efficient access to pyridine‐fused polycyclic architectures. In particular, a large variety of aryl or heteroaryl rings such as furans, thiophenes and pyridines can be incorporated into the follow‐up cyano‐Diels–Alder reactions, highlighting the great synthetic utility of this chemistry.
Remote Construction of Chiral Vicinal Tertiary and Quaternary Centers by Catalytic Asymmetric 1,6‐Conjugate Addition of Prochiral Carbon Nucleophiles to Cyclic Dienones
Authors: Wei Yuan , Liu Zunwu , Wu Xinxin , Fei Jie , Gu Xiaodong , Yuan Xiaoqian , Ye Jinxing
Published: November 2015

An unprecedented remote construction of chiral vicinal tertiary and quaternary centers by a catalytic asymmetric 1,6‐conjugate addition of prochiral carbon nucleophiles to cyclic dienones has been developed. Both 5H‐oxazol‐4‐ones and 2‐oxindoles were found to be very efficient carbon nucleophiles in this reaction at a remote position, giving products with excellent enantio‐ and diastereoselectivities (up to 99 % ee and >19:1 d.r. for 5H‐oxazol‐4‐ones and up to 97 % ee and >19:1 d.r. for 2‐oxindoles).
Evaluation of the Synthetic Potential of an AHBA Knockout Mutant of the Rifamycin Producer Amycolatopsis mediterranei
Authors: Bułyszko Ilona , Dräger Gerald , Klenge Anja , Kirschning Andreas
Published: November 2015

Supplementing an AHBA(−) mutant strain of Amycolatopsis mediterranei, the rifamycin producer, with a series of benzoic acid derivatives yielded new tetraketides containing different phenyl groups. These mutasynthetic studies revealed unique reductive properties of A. mediterranei towards nitro‐ and azidoarenes, leading to the corresponding anilines. In selected cases, the yields of mutaproducts (fermentation products isolated after feeding bacteria with chemically prepared analogs of natural building blocks) obtained are in a range (up to 118 mg L−1) that renders them useful as chiral building blocks for further synthetic endeavors. The configuration of the stereogenic centers at C6 and C7 was determined to be 6R,7S for one representative tetraketide. Importantly, processing beyond the tetraketide stage is not always blocked when the formation of the bicyclic naphthalene precursor cannot occur. This was proven by formation of a bromo undecaketide, an observation that has implications regarding the evolutionary development of rifamycin biosynthesis.
Hypervalent Activation as a Key Step for Dehydrogenative ortho CC Coupling of Iodoarenes
Authors: Wu Yichen , Arenas Ismael , Broomfield Lewis Marc , Martin Eddy , Shafir Alexandr
Published: November 2015

Building on earlier results, a direct metal‐free α‐ arylation of substituted cyclic 1,3‐diones using ArI(O2CCF3)2 reagents has been developed; unlike other arylative approaches, the arylated products retain the iodine substituent ortho to the newly formed CC bond. The mechanism is explored by using DFT calculations, which show a vanishingly small activation barrier for the CC bond‐forming step. In fact, taking advantage of an efficient in situ hypervalent activation, the iodoarenes are shown to undergo a cross‐ dehydrogenative CC coupling at the CH ortho to the iodine. When Oxone is used as terminal oxidant, the process is found to benefit from a rapid initial formation of the hypervalent ArI(OR)2 species and the sulfate‐accelerated final coupling with a ketone. This method complements the ipso selectivity obtained in the metal‐catalyzed α‐arylation of carbonyl compounds.
ChemInform Abstract: Synthesis and Characterization of a Disordered Variant of KB5O7(OH)2.
Authors: Ortner Teresa S. , Schauperl Michael , Wurst Klaus , Hofer Thomas S. , Huppertz Hubert
Published: November 2015

The title compound is hydrothermally synthesized from a mixture of KNO3, B2O3, and Ce(NO3)3·6H2O with a molar ratio of 1:1:0.07 (autoclave, 513 K, 3 d).
ChemInform Abstract: Two Hexagonal Series of Lanthanoid(III) Oxide Fluoride Selenides: M6O2F8Se3 (M: La—Nd) and M2OF2Se (M: Nd, Sm, Gd—Ho).
Authors: Zimmermann Dirk D. , Grossholz Hagen , Wolf Sarah , Janka Oliver , Mueller Alexander C. , Schleid Thomas
Published: November 2015

The two series of title compounds are prepared from mixtures of MF3 (M: La—Nd, Sm, Gd—Ho), M2O3, M, and Se using excess CsI as a flux (Nb tubes, 850 °C, 10 d).
ChemInform Abstract: Phosphine‐Free Synthesis and Characterization of Cubic‐Phase Cu2SnTe3 Nanocrystals with Optical and Optoelectronic Properties.
Authors: Wang Wenliang , Feng Wenling , Ding Tao , Yang Qing
Published: November 2015

Cu2SnTe3 nanocrystals with a cubic structure are prepared by reacting stoichiometric amounts of Cu(acac)2 and Ph4Sn in presence of oleylamine (argon atmosphere, 130 °C, 30 min) followed by injection of a TeO2 solution in 1‐dodecanethiol (210 °C, 90 min).
ChemInform Abstract: New Synthesis Route and Magnetic Structure of Tm2Mn2O7 Pyrochlore.
Authors: Pomjakushina Ekaterina , Pomjakushin Vladimir , Rolfs Katharina , Karpinski Janusz , Conder Kazimierz
Published: November 2015

Phase‐pure Tm2Mn2O7 pyrochlore is prepared by oxidation of TmMnO3 (high‐pressure apparatus, 1100 °C, 1.3 kbar O2 pressure, 20 h).
ChemInform Abstract: The Ternary System Tm—Ni—In at 870 K.
Authors: Tyvanchuk Yuriy B. , Lukachuk Maryana , Poettgen Rainer , Szytula Andrzej , Kalychak Yaroslav M.
Published: November 2015

The title system is investigated by powder XRD.
ChemInform Abstract: Hydrothermal Synthesis, Structure, and Property Characterization of Rare Earth Silicate Compounds: NaBa3Ln3Si6O20 (Ln: Y, Nd, Sm, Eu, Gd).
Authors: Sanjeewa Liurukara D. , Fulle Kyle , McMillen Colin D. , Wang Fenglin , Liu Yufei , He Jian , Anker Jeffrey N. , Kolis Joseph W.
Published: November 2015

The title compounds are hydrothermally synthesized from aqueous NaOH solutions of BaO, Ln2O3 (Ln: Y, Nd, Sm, Eu, Gd), and SiO2 in a 6:3:12 molar ratio (silver ampules, autoclave, 600—620 °C, 6 d).
ChemInform Abstract: Synthesis, Structure, and Photoluminescence Properties of an Organically‐Templated Uranyl Selenite.
Authors: Liu Dong‐Sheng , Kuang Han‐Mao , Chen Wen‐Tong , Luo Qiu‐Yan , Sui Yan
Published: November 2015

The uranyl selenite (H2en) [(UO2)(SeO3)(HSeO3)] (NO3)·0.5H2O is synthesized by slow evaporation of an aqueous mixture of UO2(NO3)2, SeO2, and en (56% yield).
ChemInform Abstract: Nucleophilic β‐Carbon Activation of Propionic Acid as a 3‐Carbon Synthon by Carbene Organocatalysis.
Authors: Jin Zhichao , Jiang Ke , Fu Zhenqian , Torres Jaume , Zheng Pengcheng , Yang Song , Song Bao‐An , Chi Yonggui Robin
Published: November 2015

An enantioselective reaction of α‐ketoesters (I) with propionic acid proceeds readily in the presence of an optically active indanol‐derived triazolium catalyst to afford chiral lactones (III).
ChemInform Abstract: Nickel‐Catalyzed Asymmetric Transfer Hydrogenation of Conjugated Olefins.
Authors: Guo Siyu , Yang Peng , Zhou Jianrong (Steve)
Published: November 2015

Asymmetric transfer hydrogenation of electron‐deficient olefins, e.g. (I), (III), and (V) is realized with Ni‐catalysts supported by strongly σ‐donating bisphosphines.
ChemInform Abstract: Ni‐Catalyzed Asymmetric Cycloisomerization of Dienes by Using TADDOL Phosphoramidites.
Authors: Schmitz Christian , Leitner Walter , Francio Giancarlo
Published: November 2015

A library of 34 monodentate TADDOL‐type phosphoramidites is prepared and their catalytic activity in the enantioselective cycloisomerization of diallyl substrates of type (I) is demonstrated.
ChemInform Abstract: Removable Silyl Group as a “Masked Proton” in Oxy‐2‐oxonia(azonia)‐Cope Rearrangement: Applications in Stereoselective Total Synthesis of Natural Macrolides.
Authors: Mu Wenbo , Zou Yue , Zhou Lijun , Wang Quanrui , Goeke Andreas
Published: November 2015

In the presence of a Lewis acid catalyst, β,γ‐unsaturated ketones bearing a vinylic TMS directing group react with aldehydes or imines to furnish zwitterionic intermediates, which undergo an oxy‐2‐oxonia(azonia)‐Cope rearrangement.
ChemInform Abstract: Boron‐Catalyzed N‐Alkylation of Amines Using Carboxylic Acids.
Authors: Fu Ming‐Chen , Shang Rui , Cheng Wan‐Min , Fu Yao
Published: November 2015

N‐Alkylation of primary and secondary amines with carboxylic acids proceeds in the presence of B(C6F5)3 as the catalyst and silanes as reducing agent.
ChemInform Abstract: Chiral Bis(imidazolidine)‐Derived NCN Pincer Rh Complex for Catalytic Asymmetric Mannich Reaction of Malononitrile with N‐Boc Imines.
Authors: Arai Takayoshi , Moribatake Takuma , Masu Hyuma
Published: November 2015

The chiral NCN‐Rh complex (TBP) is demonstrated to be an efficient catalyst for the asymmetric Mannich reaction of N‐Boc imines with malononitrile.
ChemInform Abstract: Selective Michael Reaction Controlled by Supersilyl Protecting Group.
Authors: Izumiseki Atsuto , Yamamoto Hisashi
Published: November 2015

Selective single and double Michael addition reactions of lithium organyls to acrylates are achieved using —Si(SiEt3)3 (supersilyl) as a carboxyl protecting group.
ChemInform Abstract: Nickel‐ or Cobalt‐Catalyzed Cross‐Coupling of Arylsulfonic Acid Salts with Grignard Reagents.
Authors: Malapit Christian A. , Visco Michael D. , Reeves Jonathan T. , Busacca Carl A. , Howell Amy R. , Senanayake Chris H.
Published: November 2015

CoCl2(PCy3)2 as catalyst is also applicable though it results in somewhat lower yields.
ChemInform Abstract: Nickel‐Catalyzed Alkyl—Alkyl Cross‐Couplings of Fluorinated Secondary Electrophiles: A General Approach to the Synthesis of Compounds Having a Perfluoroalkyl Substituent.
Authors: Liang Yufan , Fu Gregory C.
Published: November 2015

A convenient and mild method is presented for the coupling of fluorinated alkyl halides with alkylzinc reagents.
ChemInform Abstract: Facile Access to Fluoromethylated Arenes by Nickel‐Catalyzed Cross‐Coupling Between Arylboronic Acids and Fluoromethyl Bromide.
Authors: An Lun , Xiao Yu‐Lan , Min Qiao‐Qiao , Zhang Xingang
Published: November 2015

The title reaction proceeds under mild conditions and exhibits excellent functional group compatibility.
ChemInform Abstract: Catalytic Asymmetric Cascade Vinylogous Mukaiyama 1,6‐Michael/Michael Addition of 2‐Silyloxyfurans with Azoalkenes: Direct Approach to Fused Butyrolactones.
Authors: Li Jun , Huang Rong , Xing Yi‐Kang , Qiu Guofu , Tao Hai‐Yan , Wang Chun‐Jiang
Published: November 2015

This unprecedented cascade reaction yields pyridazine‐fused butyrolactones and butyrolactams in high yields and with excellent enantio‐ and diastereoselectivities from silyloxy‐substituted furans and pyrroles.
ChemInform Abstract: Copper‐Catalyzed Regioselective Hydroalkylation of 1,3‐Dienes with Alkyl Fluorides and Grignard Reagents.
Authors: Iwasaki Takanori , Shimizu Ryohei , Imanishi Reiko , Kuniyasu Hitoshi , Kambe Nobuaki
Published: November 2015

The copper catalysis features the selective hydroalkylation of 1,3‐dienes over alkenes and alkynes, a catalytic cleavage of the C—F bond, and a selective C—C bond formation at the relatively congested internal carbon of the dienes.
ChemInform Abstract: A Recyclable CO Surrogate in Regioselective Alkoxycarbonylation of Alkenes: Indirect Use of Carbon Dioxide.
Authors: Gehrtz P. H. , Hirschbeck V. , Fleischer I.
Published: November 2015

The CO gas stream (max.
ChemInform Abstract: Olefin‐Directed Palladium‐Catalyzed Regio‐ and Stereoselective Oxidative Arylation of Allenes.
Authors: Zhu Can , Yang Bin , Jiang Tuo , Baeckvall Jan‐E.
Published: November 2015

The olefin moiety is found to be a crucial element for the regio‐ and stereoselective arylation of various allenes to give 1,3,6‐trienes.
ChemInform Abstract: Ligand‐Assisted Gold‐Catalyzed Cross‐Coupling with Aryldiazonium Salts: Redox Gold Catalysis Without an External Oxidant.
Authors: Cai Rong , Lu Mei , Aguilera Ellen Y. , Xi Yumeng , Akhmedov Novruz G. , Petersen Jeffrey L. , Chen Hao , Shi Xiaodong
Published: November 2015

Aryldiazonium salts work both as coupling partners and, with assistance of the bipy ligand, as reagents for oxidation of gold(I) to gold(III).
ChemInform Abstract: Selective Formation of ortho‐Aminobenzylamines by the Copper‐Catalyzed Amination of Benzylamine Boronate Esters.
Authors: McGarry Kathryn A. , Duenas Alexi A. , Clark Timothy B.
Published: November 2015

Copper‐catalyzed coupling of ortho‐(aminomethyl)benzeneboronates with primary aromatic amines leads to ortho‐aminobenzylamines.
ChemInform Abstract: A Mild CuBr—NMO Oxidative System for the Coupling of Anilines Leading to Aromatic Azo Compounds.
Authors: Singh Shikha , Chauhan Parul , Ravi Makthala , Taneja Isha , Wahajuddin Wahajuddin , Yadav Prem. P.
Published: November 2015

Homo‐ as well as cross‐coupling azo compounds are accessible though in the latter case homo‐coupling products are often formed as byproducts.
ChemInform Abstract: Practical Ligand‐Free Copper‐Catalyzed Short‐Chain Alkoxylation of Unactivated Aryl Bromides.
Authors: Guo Ying , Fan Xue‐Min , Nie Min , Liu Hong‐Wei , Liao Dao‐Hua , Pan Xian‐Dao , Ji Ya‐Fei
Published: November 2015

Sodium alkoxides are used as nucleophiles in the procedure and the corresponding alcohol acts as the solvent.
ChemInform Abstract: Deep Eutectic Mixture Catalyzed the Synthesis of Disulfides Using Bunte Salts as Thiol Surrogates.
Authors: Zhou Yongsheng
Published: November 2015

An eutectic mixture of choline chloride and toluenesulfonic acid is used for the synthesis of disulfides from Bunte salts in the presence of an oxidant.
ChemInform Abstract: 2,2′‐Bis‐substituted Biphenyls by the Addition of Nucleophiles to Benzyne Followed by in situ Oxidative Homocoupling.
Authors: Sibbel Friederike , Daniliuc Constantin G. , Studer Armido
Published: November 2015

In a first step, Mg anilides or thiolates are added to benzyne, generated in situ from precursor (I).
ChemInform Abstract: Dialkylzinc‐Mediated Allylic Polyfluoroarylation Reaction.
Authors: Kurauchi Daisuke , Hirano Keiichi , Kato Hisano , Saito Tatsuo , Miyamoto Kazunori , Uchiyama Masanobu
Published: November 2015

Iodine‐zinc exchange and subsequent substitution reaction of polyfluoroaryl iodides with allylic bromides affords polyfluoroarylation products.
ChemInform Abstract: Cycloaddition of Alkyl Azides to Fullerene C60 in the Presence of Cu(OTf)2.
Authors: Akhmetov Arslan R. , Tuktarov Airat R. , Popod'ko Natal'ya R. , Dzhemilev Usein M.
Published: November 2015

A highly selective method for the cycloaddition of linear and cyclic azides to fullerene C60 promoted by copper triflate is presented, which provides a fairly simple and effective access to the new practically important N‐(cyclo)alkylaziridinofullerenes with various substituents including those based on natural compounds.
ChemInform Abstract: Organocatalytic Enantioselective Formal Arylation of Azlactones Using Quinones as the Aromatic Partner.
Authors: Li Guofeng , Sun Wangsheng , Li Jingyi , Jia Fengjing , Hong Liang , Wang Rui
Published: November 2015

A series of tricyclic furan derivatives (III) is prepared by a domino arylation‐cyclization reaction of quinones (I) with azlactones (II) in the presence of a chiral squaramide catalyst.
ChemInform Abstract: Synthesis and Isolation of Enantiomerically Enriched Cyclopenta[b]benzofurans Based on Products from Anodic Oxidation of 2,4‐Dimethylphenol.
Authors: Mirion Michael , Andernach Lars , Stobe Caroline , Barjau Joaquin , Schollmeyer Dieter , Opatz Till , Luetzen Arne , Waldvogel Siegfried R.
Published: November 2015

Tetramer (I) is obtained by anodic oxidation of 2,4‐dimethylphenol as reported in a previous paper.
ChemInform Abstract: Chiral N,O‐Ligand/[Cu(OAc)2]‐Catalyzed Asymmetric Construction of 4‐Aminopyrrolidine Derivatives by 1,3‐Dipolar Cycloaddition of Azomethine Ylides with α‐Phthalimidoacrylates.
Authors: Wang Zheng , Yu Xingxin , Tian Bo‐Xue , Payne Daniel T. , Yang Wu‐Lin , Liu Yang‐Zi , Fossey John S. , Deng Wei‐Ping
Published: November 2015

Among various chiral N,O‐ligands tested, the 7‐chloro derivative CQI is found to be the optimal one.
ChemInform Abstract: Synthesis of a C—N Axially Chiral N‐Arylisatin Through Asymmetric Intramolecular N‐Arylation.
Authors: Nakazaki Atsuo , Miyagawa Keitaro , Miyata Noriaki , Nishikawa Toshio
Published: November 2015

An optimized approach allows the preparation of the N‐aryloxindole (II) with a high level of enantiocontrol.
ChemInform Abstract: Vinylogous Reactivity of Oxindoles Bearing Nonsymmetric 3‐Alkylidene Groups.
Authors: Di Iorio Nicola , Righi Paolo , Ranieri Silvia , Mazzanti Andrea , Margutta Riccardo G. , Bencivenni Giorgio
Published: November 2015

A protocol for site‐ and enantioselective vinylogous Michael reactions of oxindoles possessing non‐equivalent γ‐ and γ′‐positions is developed.
ChemInform Abstract: An Au(I)‐Catalyzed Rearrangement/Cyclization Cascade Toward the Synthesis of 2‐Substituted‐1,4,5,6‐tetrahydrocyclopenta[b]pyrrole.
Authors: Mou Xue‐Qing , Xu Zheng‐Liang , Wang Shao‐Hua , Zhu Dao‐Yong , Wang Jie , Bao Wen , Zhou Shi‐Jiang , Yang Chao , Zhang Di
Published: November 2015

Au(I)‐catalyzed tandem reaction of cyclobutanol derivatives (I) and primary amines (II) involves a Meyer—Schuster rearrangement/1,2‐migration/Paal—Knorr cyclization cascade furnishing cyclopentapyrroles.
ChemInform Abstract: Synthesis of Polysubstituted Pyrroles Derivatives by PPh3‐Promoted Condensation Reaction Between Ninhydrin, 2‐Amino Pyridine Derivatives and Acetylenes.
Authors: Shams Nasim , Mosslemin Mohammad Hossein , Anaraki‐Ardakani Hossein
Published: November 2015

The one‐pot, three‐component intermolecular Wittig reaction furnishes polysubstituted pyrroles from readily available starting materials under mild conditions without the use of a base or an acid.