bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: Reaction of Methyl 1‐Bromocyclopentanecarboxylate with Zinc and 1‐Aryl‐5‐phenylpenta‐1,4‐dien‐3‐ones.
Authors: Kirillov N. F. , Slepukhin P. A. , Gorbunov A. A. , Gavrilov A. G. , Vakhrin M. I. 
Published: February 2013

AbstractThe reaction of dienones (I) with cyclopentane derivative (II) gives rise to the formation of a mixture of regioisomeric spiro compounds (III) and (IV).
ChemInform Abstract: Five‐Membered 2,3‐Dioxoheterocycles. Part 87. [4 + 2]‐Cycloaddition of Alkyl Vinyl Ethers and 3,4‐Dihydro‐2H‐pyran to 4,5‐Diaroyl‐1H‐pyrrole‐2,3‐diones.
Authors: Silaichev P. S. , Kudrevatykh N. V. , Maslivets A. N. 
Published: February 2013

AbstractThe reactions of pyrrolediones (I) and (IV) with alkyl vinyl ethers (II) and dihydropyran (V) are studied, aiming at the investigation of the effect of the aroyl fragment in 1H‐pyrrole‐2,3‐diones.
ChemInform Abstract: Enantioselective Synthesis of Coumarin Derivatives by PYBOX‐DIPH‐Zn(II) Complex Catalyzed Michael Reaction.
Authors: Ray Sumit K. , Singh Pradeep K. , Molleti Nagaraju , Singh Vinod K. 
Published: February 2013

AbstractIn the presence of the title complex, 4‐hydroxycoumarins smoothly react with the pyridine oxide (II) to afford 3‐substituted derivatives like (III) and (IX) with good to high enantioselectivity.
ChemInform Abstract: An Efficient One‐Pot Synthesis and Photoinduced DNA Cleavage Studies of 2‐Chloro‐3‐(5‐aryl‐4,5‐dihydroisoxazol‐3‐yl)quinolines.
Authors: Bindu P. J. , Mahadevan K. M. , Naik T. R. Ravikumar 
Published: February 2013

AbstractQuinolinyl chalcones (I), obtained by Claisen—Schmidt condensation, undergo cyclization upon treatment with hydroxylamine in the presence of a base to afford the title quinolines (II) in high yields.
ChemInform Abstract: Convergent Domino Synthesis of 1,2,3‐Triaroylindolizines from Methyl Ketones and Pyridines via Self‐Division of Labor Strategy.
Authors: Yang Yan , Gao Meng , Zhang Dong‐Xue , Wu Liu‐Ming , Shu Wen‐Ming , Wu An‐Xin 
Published: February 2013

AbstractThe reaction tolerates a wide range of aromatic and heteroaromatic substituents in methyl ketones, but no product is observed when and α,β‐unsaturated analogue is applied [cf.
ChemInform Abstract: Polycyclic N‐Heterocyclic Compounds. Part 71. Synthesis and Bronchodilator Evaluation of 5‐Substituted 1,2‐Dihydrofuro[3,2‐f][1,7]naphthyridines and Related Compounds.
Authors: Okuda Kensuke , Matsushita Tetsuo , Hirota Takashi , Sasaki Kenji 
Published: February 2013

AbstractA variety of 5‐substituted dihydrofuronaphthyridines as well as related tetracyclic compounds (IV), (VII) is synthesized and evaluated for their bronchodilatory activity.
ChemInform Abstract: Utility of Enaminonitriles in Heterocyclic Synthesis: Synthesis of Some New Pyrazole, Pyridine, and Pyrimidine Derivatives.
Authors: Fadda Ahmed A. , Etman Hassan A. , El‐Seidy Mohamed Y. , Elattar Khaled M. 
Published: February 2013

AbstractThe scope and applicability of dicyanide (I) as a unique precursor for the synthesis of some enaminonitriles and their behavior toward various reagents in which an antipyrine ring is incorporated is studied.
ChemInform Abstract: Synthesis of New Heterocyclic System, Pyrido[3,2‐e][1,3]thiazine by Mannich Reaction.
Authors: Dyachenko V. D. , Nikishin A. A. , Dyachenko A. D. 
Published: February 2013

AbstractAminomethylation of tetrahydropyridine thiolate (I) with primary amines (II) and formaldehyde (III) under Mannich reaction conditions leads to formation of the new heterocyclic system (IV).
ChemInform Abstract: Fused Heterocyclic Systems with s‐Triazine Ring. Part 18. Synthesis and Structure of 3,4‐Dihydropyrido[2′,3′:3,4]pyrazolo[1,5‐a][1,3,5]triazin‐2‐amines.
Authors: Dolzhenko Anton V. , Bai Shiqi , Dolzhenko Anna V. , Chui Wai Keung 
Published: February 2013

Abstract1H‐Pyrazolo[3,4‐b]pyridin‐ylguanidine (IV) is synthesized as a new convenient synthon for heterocyclic chemistry by selective guanylation of amine (II).
ChemInform Abstract: Novel Heterocyclic Derivatives of 2‐Quinolinone Associated with Antibacterial and Antitumor Potencies.
Authors: Hassanin Hany M. , El‐edfawy Somaya M. 
Published: February 2013

AbstractQuinolinone derivative (II) is subjected to reactions with 1,3‐binucleophiles, 1,4‐binucleophiles, and 1,4‐N,N‐binucleophiles to obtain new quinolinones bearing imidazole, c.f.
ChemInform Abstract: Fused Heterocyclic Systems with s‐Triazine Ring. Part 21. Synthesis of Novel Trichloromethyl Substituted Azolo[1,3,5]triazines.
Authors: Kalinin Dmitrii V. , Kalinina Svetlana A. , Dolzhenko Anton V. 
Published: February 2013

AbstractThe reaction of azoles (I) with trichloroacetonitrile (II) proceeds smoothly and regioselectively at the primary amino group of (I) to yield the trichloroacetamidines (III).
ChemInform Abstract: Synthesis of 1,2,4‐Triazepine and 1,2,5‐Triazocine Derivatives from the Reaction of 2‐Aminobenzohydrazide with π‐Acceptors.
Authors: El‐Shaieb Kamal M. , Ameen Mohamed A. , Abdel‐Latif Fathy F. , Mohamed Asmaa H. 
Published: February 2013

AbstractA convenient, one‐pot method for the preparation of 1,2,4‐triazepine and 1,2,5‐triazocine derivatives is described.
ChemInform Abstract: Synthesis of Dihydrodibenzo[b,f]furo[2,3‐d]oxepins and Related Reactions.
Authors: Maemura Yasunobu , Tanoue Yuka , Nishino Hiroshi 
Published: February 2013

AbstractThe annulation of dibenzoxepins (I) is based on Mn(III)‐initiated oxidative radical cyclization yielding the lactone‐ and dihydrofuran‐fused dibenzoxepin derivatives (III),(V), and (VII).
ChemInform Abstract: Palladium‐Catalyzed Borylation of Aryl and Heteroaryl Halides Utilizing Tetrakis(dimethylamino)diboron: One Step Greener.
Authors: Molander Gary A. , Trice Sarah L. J. , Kennedy Steven M. 
Published: February 2013

AbstractThe novel borylating reagent, a synthetic precursor of bis(pinacolato)diboron and bis‐boronic acid (BBA), can be used for a broad spectrum of substrates where only iodides are less efficient.
ChemInform Abstract: Two New Chromanone Derivatives from the Roots and Stems of Nicotiana tabacum and Their Cytotoxicity.
Authors: Mou Dingrong , Zhao Wei , Zhang Tao , Wan Lan , Yang Guangyu , Chen Yongkuan , Hu Qiufen , Miao Mingming 
Published: February 2013

AbstractTabchromones A(Ia) and B(Ib) are isolated from the title plant together with four known compounds.
Preference for color‐enhanced images assessed by color deficiencies
Authors: Chen Yi‐Chun , Guan Yunge , Ishikawa Tomoharu , Eto Hiroaki , Nakatsue Takehiro , Chao Jinhui , Ayama Miyoshi 
Published: February 2013

AbstractIn this study, we propose color images with color enhancement for congenital red–green color deficiency on the basis of the model proposed by Mochizuki et al. [In Terrassa, Spain: Proceedings for CGIV, Springfield VA: IS&T 2008;208–213] with the aim of facilitating color customization in displays used by color‐deficient observers. Three types of color enhancements for deficiency were addressed in this study: colors were enhanced along the protan confusion line (i.e., P‐enhancement), deutan confusion line (i.e., D‐enhancement), and a line between the protan and deutan confusion lines (i.e., mix‐enhancement). We investigated the color‐enhanced image that is most preferred by each group of protan, deutan, and normal observers. Protan and deutan in this study indicate observers that are both dichromats and anomalous trichromats. Nine protan, nine deutan, and six normal observers participated in the experiment. The results showed that among the three types of color enhancements, the D‐enhancement provided the best performance for protan observers. For deutan observers, all three types provided effective enhancement, although the P‐ and mix‐enhancements were slightly better than the D‐enhancement. Our results indicated that color enhancement increases the preference evaluations of protan and deutan observers.  © 2013 Wiley Periodicals, Inc. Col Res Appl, 39, 234–251, 2014; Published Online 20 February 2013 in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/col.21795
Molecular Switching Behavior in Isosteric DNA Base Pairs
Authors: Jissy A. K. , Konar Sukanya , Datta Ayan 
Published: February 2013

AbstractThe structures and proton‐coupled behavior of adenine–thymine (A‐T) and a modified base pair containing a thymine isostere, adenine–difluorotoluene (A‐F), are studied in different solvents by dispersion‐corrected density functional theory. The stability of the canonical Watson–Crick base pair and the mismatched pair in various solvents with low and high dielectric constants is analyzed. It is demonstrated that A‐F base pairing is favored in solvents with low dielectric constant. The stabilization and conformational changes induced by protonation are also analyzed for the natural as well as the mismatched base pair. DNA sequences capable of changing their sequence conformation on protonation are used in the construction of pH‐based molecular switches. An acidic medium has a profound influence in stabilizing the isostere base pair. Such a large gain in stability on protonation leads to an interesting pH‐controlled molecular switch, which can be incorporated in a natural DNA tract.
Ring‐Opening Metathesis Polymerization‐based Recyclable Magnetic Acylation Reagents
Authors: Kainz Quirin M. , Linhardt Roland , Maity Pradip K. , Hanson Paul R. , Reiser Oliver 
Published: February 2013

AbstractAn operationally simple method for the acylation of amines utilizing carbon‐coated metal nanoparticles as recyclable supports is reported. Highly magnetic carbon‐coated cobalt (Co/C) and iron (Fe/C) nanobeads were functionalized with a norbornene tag (Nb‐tag) through a “click” reaction followed by surface activation employing Grubbs‐II catalyst and subsequent grafting of acylated N‐hydroxysuccinimide ROMPgels (ROMP=ring‐opening metathesis polymerization). The high loading (up to 2.6 mmol g−1) hybrid material was applied in the acylation of various primary and secondary amines. The products were isolated in high yields (86–99%) and excellent purities (all >95 % by NMR spectroscopy) after rapid magnetic decantation and simple evaporation of the solvents. The spent resins were successfully re‐acylated by acid chlorides, anhydrides, and carboxylic acids and reused for up to five consecutive cycles without considerable loss of activity.
Cellulose Conversion with Tungstated‐Alumina‐Based Catalysts: Influence of the Presence of Platinum and Mechanistic Studies
Authors: Chambon Flora , Rataboul Franck , Pinel Catherine , Cabiac Amandine , Guillon Emmanuelle , Essayem Nadine 
Published: February 2013

AbstractThe performances of platinum supported on tungstated alumina (Pt/AlW) in the hydrothermal conversion of cellulose at 190 °C under H2 pressure were evaluated and compared to that of Pt‐free tungstated alumina (AlW). We show that the presence of Pt significantly increased the extent of conversion and led to a different product distribution with the formation of acetol and propylene glycol as the main products and a global yield of up to 40 %. Based on previous reports, we propose the formation of pyruvaldehyde on the Lewis acid sites of the tungstated alumina as a key intermediate. Pyruvaldehyde can then be transformed to acetol and propylene glycol or lactic acid depending on the presence or absence of supported Pt.
Mechanistic Studies on Water‐Exchange Reactions in [Zn(H2O)4L]2+·2H2O for L = sp2, sp3 Oxygen‐Donor Ligands: A DFT Approach
Authors: Alzoubi Basam M. , Walther Markus , Puchta Ralph , van Eldik Rudi 
Published: February 2013

AbstractWater‐exchange reactions on the five‐coordinate complex [Zn(H2O)4(L)]2+·2H2O (L = water, methanol, ethanol, propan‐1‐ol, butan‐1‐ol, dimethyl ether, propan‐2‐ol, fluorophosgene, phosgene, formaldehyde, acetyl chloride, acetaldehyde, acetone and acetamide) were studied by quantum‐chemical calculations (B3LYP/6‐311+G**). The reactions follow an associative pathway that involves the formation of a six‐coordinate intermediate [Zn(H2O)5(L)]2+·H2O, followed by the dissociation of a water molecule to form the product [Zn(H2O)4(L)]2+·2H2O. The water‐exchange process involves isoenergetic cis‐ and trans‐oriented transition states to form the product state that is similar to the reactant state. Of the studied ligands L, acetamide, which has the highest basicity, exhibited the highest activation energy and energy gap between the reactant and intermediate states. Electronic and steric effects of the coordinated ligands influence the activation barrier and the efficiency of the water‐exchange process.
Oxidation of Carbene‐Derived Selenium Diiodide with Silver Tetrafluoroborate – Isolation of Iodonium Ion Complexes with Selones
Authors: Manjare Sudesh T. , Singh Harkesh B. , Butcher Ray J. 
Published: February 2013

AbstractThe oxidation reactions of diiodoselones 10a and 10b with silver tetrafluoroborate afford linear complexes of iodonium ions with selones 13a and 13b. The decomposition of the tellurium tetraiodide adduct with benzimidazolin‐2‐selone (12) in chloroform also affords a similar iodonium ion complex 13c. Crystal structure analysis of 13a–13c shows interesting supramolecular formation by C–H···F, C–H···Br, C–H···I, Se···π, and I···π interactions.
A Concise and Divergent Approach to Hydroxylated Piperidine Alkaloids and Azasugar Lactams
Authors: Guo Lian‐Dong , Liang Pan , Zheng Jian‐Feng , Huang Pei‐Qiang 
Published: February 2013

AbstractThe vinylogous Mannich reaction (VMR) between 2‐(tert‐butyldimethylsilyloxy)furan (TBSOF) and (RS)‐t‐BS‐imine 12a and the application of the VMR adduct butenolide 13a as a versatile chiral building block for the synthesis of hydroxylated piperidine alkaloids and azasugars were investigated. Firstly, both the anti diastereoselectivity and the chemical yield of the asymmetric VMR between TBSOF and (RS)‐t‐BS‐imine 12a were improved by the use of Sm(OTf)3/H2O (1.5 equiv.) as the promoter. Similar diastereoselectivities were also obtained with Yb(OTf)3/H2O, Cu(OTf)2/H2O, Zn(OTf)2/H2O, or the Brønsted acids TfOH or MsOH as the promotors. Secondly, an efficient four‐step procedure for the elaboration of butenolide 13a into piperidine alkaloid (–)‐deoxoprosophylline (2) was established. Thirdly, by taking advantage of the olefin functionality in the butenolide 13a, polyhydroxylated δ‐lactams 23 and 21, which are ready precursors of azasugars L‐deoxyallonojirimycin (ent‐7) and L‐3‐epi‐fagomine (ent‐6), were obtained in two and three steps, respectively, via dihydroxylated lactone 17. The easily available synthetic intermediate 17 can also serve as a key intermediate for the synthesis of the glycosyl nucleoside amino acid cores of polyoxins and nikkomycins.
Interactive effects of contaminants and climate-related stressors: High temperature increases sensitivity to cadmium
Authors: Kimberly David A. , Salice Christopher J. 
Published: February 2013

Abstract

An emerging issue in environmental toxicology is in understanding how climate change will alter responses of organisms to chemical contaminants. The objective of the present study was to characterize the interactive effects of cadmium and elevated temperature on life-stage-specific responses in the freshwater snail Physa pomilia. We exposed developing eggs, juveniles, and adults to Cd (5 µg/L, 15 µg/L, and 25 µg/L for eggs, and 250 µg/L for juveniles and adults) and 2 temperatures of 25 °C (control) and 35 °C (upper range of tolerance). In the absence of Cd, time to hatch was shorter at 35 °C compared with 25 °C, demonstrating a stimulatory effect of the higher temperature. However, when egg masses were reared at 35 °C and exposed to Cd, hatching success was significantly lower, and time-to-hatching was significantly longer. The effects of the higher temperature and Cd on newly hatched neonate survival were additive, except at the highest Cd concentration, at which effects of the 2 stressors were greater than additive. Overall, within the combined stressor treatments, adult snails generally survived significantly longer than did juvenile snails, and both were more tolerant than developing snails. Many climate projection models predict future increases in global temperatures. The present study shows that combined stressors may produce greater-than-additive effects, challenging predictive power. More studies are needed to better characterize the interactive effects of chemical contaminants and stressors related to climate change. Environ Toxicol Chem 2013;32:1337–1343. © 2013 SETAC
The mode of deformation in the orogenic mid‐crust revealed by seismic attribute analysis
Authors: Torvela Taija , Moreau Julien , Butler Robert W. H. , Korja Annakaisa , Heikkinen Pekka 
Published: February 2013

AbstractThe processes and the structures within the middle and the lower crust are intimately related to the evolution of orogenies, but more detailed knowledge is needed of these deep crustal processes. Seismic reflection data, chiefly displayed in amplitude, are commonly used to interpret deep crustal structures. The strongest amplitude events are probably related to lithological changes and do not necessarily correspond to geological structures, tectonic boundaries, or deformation fabrics. Furthermore, the detailed structures and the strain distribution between the interpreted structural boundaries remain obscure. Here, we show an example of how seismic attributes, combined with the seismic facies interpretation technique, can be used to enhance 2D seismic reflection data from the Palaeoproterozoic Svecofennian crust of southern Finland, to reveal unprecedentedly detailed information about the deformation fabrics within the mid‐crust of a collisional orogen. The images are plausibly interpreted to show that the extension/lateral flow of the orogenic middle and lower crust was mainly accommodated by kilometer‐scale S‐C′ structures. The structures form penetrative deformation fabrics which are correlated with outcrop observations. The successful enhancement of the seismic data confirms the ductile extension affecting hot orogenic crust, and gives new information about the strain distribution of the regional, syn‐ to late‐orogenic deformation. The seismic attribute method and the seismic facies interpretational approach described in this paper should be applicable to other seismic datasets from the crystalline basement.
In situ stress and pore pressure in the Kumano Forearc Basin, offshore SW Honshu from downhole measurements during riser drilling
Authors: Saffer D. M. , Flemings P. B. , Boutt D. , Doan M.‐L. , Ito T. , McNeill L. , Byrne T. , Conin M. , Lin W. , Kano Y. , Araki E. , Eguchi N. , Toczko S. 
Published: February 2013

AbstractIn situ stress and pore pressure are key parameters governing rock deformation, yet direct measurements of these quantities are rare. During Integrated Ocean Drilling Program (IODP) Expedition #319, we drilled through a forearc basin at the Nankai subduction zone and into the underlying accretionary prism. We used the Modular Formation Dynamics Tester tool (MDT) for the first time in IODP to measure in situ minimum stress, pore pressure, and permeability at 11 depths between 729.9 and 1533.9 mbsf. Leak‐off testing at 708.6 mbsf conducted as part of drilling operations provided a second measurement of minimum stress. The MDT campaign included nine single‐probe (SP) tests to measure permeability and in situ pore pressure and two dual‐packer (DP) tests to measure minimum principal stress. Permeabilities defined from the SP tests range from 6.53 × 10−17 to 4.23 × 10−14 m2. Pore fluid pressures are near hydrostatic throughout the section despite rapid sedimentation. This is consistent with the measured hydraulic diffusivity of the sediments and suggests that the forearc basin should not trap overpressures within the upper plate of the subduction zone. Minimum principal stresses are consistently lower than the vertical stress. We estimate the maximum horizontal stress from wellbore failures at the leak‐off test and shallow MDT DP test depths. The results indicate a normal or strike‐slip stress regime, consistent with the observation of abundant active normal faults in the seaward‐most part of the basin, and a general decrease in fault activity in the vicinity of Site C0009.
Timing, origin and emplacement dynamics of mass flows offshore of SE Montserrat in the last 110 ka: Implications for landslide and tsunami hazards, eruption history, and volcanic island evolution
Authors: Trofimovs J. , Talling P. J. , Fisher J. K. , Sparks R. S. J. , Watt S. F. L. , Hart M. B. , Smart C. W. , Le Friant A. , Cassidy M. , Moreton S. G. , Leng M. J. 
Published: February 2013

AbstractMass flows on volcanic islands generated by volcanic lava dome collapse and by larger‐volume flank collapse can be highly dangerous locally and may generate tsunamis that threaten a wider area. It is therefore important to understand their frequency, emplacement dynamics, and relationship to volcanic eruption cycles. The best record of mass flow on volcanic islands may be found offshore, where most material is deposited and where intervening hemipelagic sediment aids dating. Here we analyze what is arguably the most comprehensive sediment core data set collected offshore from a volcanic island. The cores are located southeast of Montserrat, on which the Soufriere Hills volcano has been erupting since 1995. The cores provide a record of mass flow events during the last 110 thousand years. Older mass flow deposits differ significantly from those generated by the repeated lava dome collapses observed since 1995. The oldest mass flow deposit originated through collapse of the basaltic South Soufriere Hills at 103–110 ka, some 20–30 ka after eruptions formed this volcanic center. A ~1.8 km3 blocky debris avalanche deposit that extends from a chute in the island shelf records a particularly deep‐seated failure. It likely formed from a collapse of almost equal amounts of volcanic edifice and coeval carbonate shelf, emplacing a mixed bioclastic‐andesitic turbidite in a complex series of stages. This study illustrates how volcanic island growth and collapse involved extensive, large‐volume submarine mass flows with highly variable composition. Runout turbidites indicate that mass flows are emplaced either in multiple stages or as single events.
Olivine thermometry and source constraints for mantle fragments in the Navajo Volcanic Field, Colorado Plateau, southwest United States: Implications for the mantle wedge
Authors: Smith Douglas 
Published: February 2013

AbstractThe evolution of the mantle wedge below the Colorado Plateau during low‐angle subduction has been investigated by analysis of fragments from the Navajo Volcanic Field (NVF), most from serpentinized ultramafic microbreccia (SUM) diatremes. In most SUM‐hosted olivine, concentrations of Al and V are < 1 ppm, and Cr, Ca, and Na concentrations also are unusually low: most temperatures from three olivine thermometers (Al, Cr, and V‐based) are in the range 530°C to 650°C. The temperatures are consistent with the presence of chlorite in some inclusions, and they support the utility of olivine thermometry for diverse mineral assemblages in cool peridotite. Most pressures calculated for discrete diopside grains in SUM correspond to depths in the range 80 to 120 km. Diopside is relatively high in Li (~3.5 ppm), and two of five diopside grains have high Sr/Nd. SUM diatreme sources are inferred to be serpentine‐rich mélange tectonically eroded from the forearc, transported above the Farallon slab, and incorporated into the lithosphere of the Plateau. Garnet peridotite xenoliths from minettes of the NVF record deeper depths in the range 120 to 150 km. These garnet peridotites also may be from forearc mantle emplaced during Farallon subduction. Calculated temperatures preclude the possibility that asthenosphere was in contact with that lithosphere at or near 150 km depth for tens of m.y. before NVF formation. Structures observed in seismic images of mantle to depths of 150 km below the central Colorado Plateau may be related to Farallon subduction, not inherited from Proterozoic lithosphere.