bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: Ultrasound Irradiated Synthesis of Bis‐pyrimidine Derivatives in Aqueous Media.
Authors: Dabholkar Vijay V. , Ansari Faisal Y. 
Published: October 2012

AbstractThe practical and convenient synthesis of bis‐pyrimidine derivatives (V) and (VII) involves a base‐mediated olefination and subsequent cyclocondensation of cinnamoyloxy derivatives (III) with (thio)urea or guanidine.
ChemInform Abstract: An Efficient, Greener, and Solvent‐Free One‐Pot Multicomponent Synthesis of 3‐Substituted Quinazolin‐4(3H)ones and Thienopyrimidin‐4(3H)ones.
Authors: Jalani Hitesh B. , Pandya Amit N. , Pandya Dhaivat H. , Sharma Jayesh A. , Sudarsanam V. , Vasu Kamala K. 
Published: October 2012

AbstractA novel efficient one‐pot procedure is developed for the sequential reaction of substrates (I) or (V) with DMF dimethyl acetal and various anilines to give quinazolinones (IV) and thienopyrimidinones (VI), respectively.
ChemInform Abstract: Synthesis of 5‐Alkynylated Uracil—Morpholino Monomers Using Sonogashira Coupling.
Authors: Paul Sibasish , Nandi Bappaditya , Pattanayak Sankha , Sinha Surajit 
Published: October 2012

AbstractSonogashira coupling of 5‐iodouracil derivatives (I) with various terminal alkynes gives the title compounds (III) (18 examples) in good yields.
ChemInform Abstract: Copper‐Catalyzed Aerobic Oxidation of N‐Substituted Hydroxylamines: Efficient and Practical Access to Nitroso Compounds.
Authors: Frazier Charles P. , Bugarin Alejandro , Engelking Jarred R. , de Alaniz Javier Read 
Published: October 2012

AbstractThe reaction succeeds also in other solvents such as various alcohols or toluene.
ChemInform Abstract: Synthesis of an Isoindoline‐Annulated, Tricyclic Sultam Library via Microwave‐Assisted, Continuous‐Flow Organic Synthesis (MACOS).
Authors: Ullah Farman , Zang Qin , Javed Salim , Porubsky Patrick , Neuenswander Benjamin , Lushington Gerald H. , Hanson Paul R. , Organ Michael G. 
Published: October 2012

AbstractA reaction sequence involving three consecutive microwave‐promoted continuous‐flow reaction steps is presented to synthesize the title compounds (V) and (VII).
ChemInform Abstract: Halogen‐Free Room‐Temperature Broensted Acidic Ionic Liquid [Hmim]+ HSO4‐ as a Recyclable Green “Dual Reagent” Catalysis for the Synthesis of Triarylmethanes (TRAMs).
Authors: Mukhopadhyay Chhanda , Datta Arup , Tapaswi Pradip Kumar 
Published: October 2012

AbstractThe protocol is chemoselective and ketones such as benzophenone or esters like ethyl formate do not react, even at prolonged time.
ChemInform Abstract: Absolute Configuration of the Meroditerpenoids Taondiol and Epitaondiol Diacetates by Vibrational Circular Dichroism.
Authors: Munoz Marcelo A. , Areche Carlos , Rovirosa Juana , San Martin Aurelio , Gordillo‐Roman Barbara , Joseph‐Nathan Pedro 
Published: October 2012

AbstractThe calculated spectra of alga meroditerpenoids taondiol diacetate (I) and epitaondiol diacetate (II) match confidently with the experimental ones.
ChemInform Abstract: Synthesis of B‐Ring‐Modified Steroids Through BF3‐Promoted Rearrangement/Substitution of 6β‐Hydroxy‐5,19‐cyclosteroids.
Authors: Kranz Darius P. , Chiha Slim , Meier zu Greffen Aike , Neudoerfl Joerg‐Martin , Schmalz Hans‐Guenther 
Published: October 2012

AbstractMe3Si‐allyl as the nucleophile gives the highest yield of the rearranged alcohol (XIII) after hydrolysis.
ChemInform Abstract: Tumescenamide C, an Antimicrobial Cyclic Lipodepsipeptide from Streptomyces sp.
Authors: Kishimoto Shinji , Tsunematsu Yuta , Nishimura Shinichi , Hayashi Yutaka , Hattori Akira , Kakeya Hideaki 
Published: October 2012

AbstractTitle compound (I) exhibits antimicrobial activity against Streptomyces species.
ChemInform Abstract: Antioxidant and Antinitric Oxide Components from Quercus glauca.
Authors: Shen Chien‐Chang , Hong Kun‐Yuan , Chen Jennifer , Zhang Li‐Jie , Lin Zhi‐Hu , Huang Hung‐Tse , Cheng Hui‐Ling , Kuo Yao‐Haur 
Published: October 2012

AbstractTwo new lignan glycosides (I) and (II) are isolated from Quercus glauca along with 14 known compounds.
ChemInform Abstract: Continuous Flow Photocatalysis Enhanced Using an Aluminum Mirror: Rapid and Selective Synthesis of 2′‐Deoxy and 2′,3′‐Dideoxynucleosides.
Authors: Shen Bo , Bedore Matthew W. , Sniady Adam , Jamison Timothy F. 
Published: October 2012

AbstractA photochemical flow reactor is developed and applied for a photoinduced electron‐transfer deoxygenation of protected nucleosides (I) and (IV).
ChemInform Abstract: Stereoselective Total Synthesis of Atpenins A4 and B, Harzianopyridone, and NBRI23477 B.
Authors: Ohtawa Masaki , Sugiyama Kouhei , Hiura Tohru , Izawa Shujiro , Shiomi Kazuro , Omura Satoshi , Nagamitsu Tohru 
Published: October 2012

AbstractUsing a convergent approach involving the coupling reaction of a common iodopyridine with an aldehyde to the appropriate side chain, the stereoselective synthesis of atpenins A4 (Ia) and B (Ib), NBRI23477 B (Ic), and harzianopyridinone (II) is developed.
ChemInform Abstract: New, Efficient, and High‐Yielding Asymmetric Synthesis of (4S,5S)‐Cytoxazone.
Authors: Babu Kollapudi Chandra , Reddy Rapolu Naveen , Rao Salluri Yellamanda , Venkateshwarlu Palnati , Madhusudhan Gutta 
Published: October 2012

AbstractKey step in the new asymmetric approach to (+)‐cytoxazone (VII) is a highly diastereoselective 1,2‐addition of anisylmagnesium bromide to the known chiral N‐sulfinimine precursor (I).
ChemInform Abstract: Dotting the i′s in Three‐Component Biginelli‐Like Condensations Using 3‐Amino‐1,2,4‐triazole as a 1,3‐Binucleophile.
Authors: Sedash Yuriy V. , Gorobets Nikolay Yu. , Chabanov Valentin A. , Konovalova Irina S. , Shishkin Oleg V. , Desenko Sergey M. 
Published: October 2012

AbstractReview: 58 refs.
Technical Factors Affecting the Size Reduction Result for Impact Milling of Medium‐Volatile Bituminous Coal
Authors: Lehmann Bastian , Schneider Diana , Schröder Hans‐Werner , Wollenberg Ralf , Repke Jens‐Uwe 
Published: October 2012

AbstractBei der Prallzerkleinerung von Gasflammkohlen in einer Universal‐Feinprallmühle kann das Zerkleinerungsergebnis durch Variation maschinentechnischer Paramater wie der Rotorgeometrie, der Geometrie der Austragssiebe sowie durch die Rotorumfangsgeschwindigkeit beeinflusst werden. Wichtige Kenngrößen sind hierbei der Zentralwert und die Breite der Partikelgrößenverteilung sowie die Energieausnutzung. Bei der untersuchten Feinprallmühle wird das Zerkleinerungsergebnis im Wesentlichen durch die Rotorumfangsgeschwindigkeit und die Sieblochgeometrie der Austragssiebe beeinflusst, wobei über die Art der Austragssiebe die Breite der Produktpartikelgrößenverteilung gezielt beeinflusst werden kann.
Enhanced Photocatalytic Activity of Thienyl‐Porphyrins‐TiO2 for Degradation of 4‐Nitrophenol
Authors: Ma Wangyang , Li Jun , Liu Jingzhou , Feng Meng 
Published: October 2012

Abstract5‐Mono‐(2‐thienyl)‐10,15,20‐triphenyl porphyrin (H2MTP) and its Co(II), Cu(II), Zn(II) metalloporphyrins (CoMTP, CuMTP, ZnMTP) were synthesized and characterized spectroscopically. The corresponding Co(II), Cu(II), Zn(II) metalloporphyrins‐TiO2 photocatalysts were then prepared and characterized by means of scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), UV‐vis spectra and FT‐IR. The photocatalytic activities of these photocatalysts were investigated by testing the photodegradation of 4‐nitrophenol (4‐NP) in aqueous solution under irradiation with high‐pressure mercury lamp and metal halide lamp respectively. The results indicated that these metalloporphyrins greatly enhanced the photocatalytic efficiency of bare TiO2 in degradating the 4‐NP, and CuMTP‐TiO2 exhibited the highest photocatalytic activity of all photocatalysts. In addition, the first order rate constants of these photocatalytic reactions were calculated.
Accurate Prediction of AuP Bond Strengths by Density Functional Theory Methods
Authors: Yu Haizhu , Liu Dingjia , Dang Zhimin , Wang Dongrui , Fu Yao 
Published: October 2012

AbstractThe recent development of Au‐catalyzed reactions has greatly enriched the methods of organic synthesis. The phosphine or phosphate‐coordinated Au complexes have shown high efficiency in catalyzing various CC and CH activations. In many of these reactions, the AuP bond strength was found to play an important role in determining the catalytic efficiency. In the present study, the accuracy of different theoretical methods for prediction of AuP strengths has been examined on basis of the experimental enthalpy changes between different ClAu(PR3) and ClAu(THT) (THT=tetrahydrothiophene). By comparing the different DFT functionals (e.g. B3LYP, TPSS, M06), different basis sets (including the different effective core potentials on Au and the total electron basis sets on all other atoms), and different solution phase single point calculations, we found that the TPSS/(CPE‐121G+f:6‐311+G(d,p)(SMD)//TPSS/(CPE‐121G:6‐31G(d) (M1) method gives the best correlations with the available experimental results. Meanwhile, the calculations with B3LYP//TPSS and M05//TPSS also give comparable calculation results. Finally, the specified method (M1) is used to calculate the AuP bond dissociation enthalpies and energies of different ClAu(PR3)/ClAu(P(OR)3) complexes. By accurately reproducing the available experimental results, we believe that the method (M1) is reliable for the theoretical analysis of Au‐P systems.
A Facile Access to Fluorinated Pyrrolidines via Catalytic Asymmetric 1,3‐Dipolar Cycloaddition of Azomethine Ylides with Methyl α‐Fluoroacrylate
Authors: Yan Dingce , Li Qinghua , Wang Chunjiang 
Published: October 2012

AbstractAsymmetric 1,3‐dipolar cycloaddition of methyl α‐fluoroacrylate with azomethine ylides for the construction of optically active fluorinated pyrrolidines bearing one unique fluorinated quaternary and two tertiary stereogenic centers has been achieved with Cu(CH3CN)4BF4/TF‐BiphamPhos complexes for the first time. This catalytic system performs well over a broad scope of substrates, providing the synthetically useful adducts in good yields and excellent diastereoselectivities and good to high enantioselectivities.
Enantioselective and α‐Regioselective Allylic Amination of Morita‐Baylis‐Hillman Acetates with Simple Aromatic Amines Catalyzed by Planarly Chiral Ligand/Palladium Catalyst
Authors: Wang Yan , Zhang Tao , Liu Li 
Published: October 2012

AbstractAn asymmetric allylic amination of Morita‐Baylis‐Hillman acetates with simple aromatic amines catalyzed by planarly chiral ligand/palladium‐catalyst was developed in good yield with excellent α‐regioselectivity (α/γ up to 30:1) and moderate enantioselectivity (up to 70% ee).
Cu(II)‐Catalyzed Enantioselective Conjugate Reduction for the Synthesis of N‐Aryl β‐Amino Acid Esters
Authors: Sui Yaozong , Fang Qiang , Li Min , Hu Yihu , Xia Hongfeng , Li Shijun , Wu Jing 
Published: October 2012

AbstractA new set of reaction conditions has been established and allowed for the first non‐noble Cu(II)‐catalyzed asymmetric 1,4‐hydrosilylation of N‐aryl β‐enamino esters under air to afford a selection of N‐aryl β‐amino acid esters of moderate‐to‐good enantiopurities (ee up to 91%).
Iridium‐Catalyzed Allylic Alkylations of Sodium Phenyl Selenide
Authors: Cui Ruimin , Guo Xinwen , Zheng Shengcai , Zhao Xiaoming 
Published: October 2012

AbstractAn iridium‐catalyzed allylic substitution of sodium phenyl selenide with unsymmetrical allyl carbonates was accomplished, which produced the linear allyl phenyl selenides in 38%–74% yields. An asymmetric iridium‐catalyzed allylation of sodium phenyl selenide was presented as well.
An Efficient Asymmetric Domino Reaction of Amino Aldehyde to β,γ‐Unsaturated α‐Keto Esters Using trans‐Perhydroindolic Acid as a Chiral Organocatalyst
Authors: Shen Jiefeng , An Qianjin , Liu Delong , Liu Yangang , Zhang Wanbin 
Published: October 2012

AbstractAn efficient asymmetric domino reaction of amino aldehyde to β,γ‐unsaturated α‐keto esters was achieved by using trans‐perhydroindolic acid 1d as a chiral organocatalyst with excellent asymmetric behavior. Under the optimal reaction conditions, products with more than 99% de and up to 93% ee were obtained in high chemical yield (up to 98%) for a series of β,γ‐unsaturated α‐keto esters. The methodology provided an efficient route to dihydropyran derivatives containing many substituent groups (including amino groups).
Ultrafast Photodynamics of the Indoline Dye D149 Adsorbed to Porous ZnO in Dye‐Sensitized Solar Cells
Authors: Rohwer Egmont , Richter Christoph , Heming Nadine , Strauch Kerstin , Litwinski Christian , Nyokong Tebello , Schlettwein Derck , Schwoerer Heinrich 
Published: October 2012

AbstractWe investigate the ultrafast dynamics of the photoinduced electron transfer between surface‐adsorbed indoline D149 dye and porous ZnO as used in the working electrodes of dye‐sensitized solar cells. Transient absorption spectroscopy was conducted on the dye in solution, on solid state samples and for the latter in contact to a I−/I3− redox electrolyte typical for dye‐sensitized solar cells to elucidate the effect of each component in the observed dynamics. D149 in a solution of 1:1 acetonitrile and tert‐butyl alcohol shows excited‐state lifetimes of 300±50 ps. This signature is severely quenched when D149 is adsorbed to ZnO, with the fastest component of the decay trace measured at 150±20 fs due to the charge‐transfer mechanism. Absorption bands of the oxidized dye molecule were investigated to determine regeneration times which are in excess of 1 ns. The addition of the redox electrolyte to the system results in faster regeneration times, of the order of 1 ns.
Sol–Gel‐Derived, Calcium‐Based, Copper‐Functionalised CO2 Sorbents for an Integrated Chemical Looping Combustion–Calcium Looping CO2 Capture Process
Authors: Kierzkowska Agnieszka M. , Müller Christoph R. 
Published: October 2012

AbstractUsing a sol–gel technique, new copper‐functionalised, calcium‐based CO2 sorbents were developed to integrate chemical looping combustion into the calcium looping scheme. In this process, the exothermic reduction of copper oxide with methane, carbon monoxide or hydrogen is used to provide the heat required to calcine (regenerate) calcium carbonate. The materials contained CuO and CaO in a molar ratio of either 1.3:1 or 3.3:1, were supported on Al2O3, MgO or MgAl2O4 and were characterised by means of X‐ray diffraction, N2 physisorption, scanning electron microscopy and temperature‐programmed reduction. All materials, independent of the precursors and support material used, possessed excellent cyclic oxygen‐carrying capacities. However, it was found that the presence of magnesium in the support stabilised the CO2 uptake and minimised carbon deposition. CuCa‐MgAl‐1.3:1 was the material that possessed the highest CO2 uptake of 0.13 g gmaterial−1 after 15 cycles of repeated carbonation/calcination–redox reactions.
Mixed metal oxide nanocomposites derived from layered double hydroxides as photocatalysts for C.I. Basic Blue 3 degradation under UV light
Authors: Rezvani Z. , Sarkarat M. , Khataee A. R. , Nejati K. 
Published: October 2012

AbstractIn this research we report synthesis of the heterostructure Mg‐Al‐Zn mixed metal oxide (ZnO/MMO) nanocomposite photocatalysts derived from Zn(OH)2/Mg‐Al‐layered double hydroxides (ZLDHs) precursors. The obtained samples were characterized by the X‐ray diffraction (XRD), FT‐IR, BET surface area, ICP and TG/DTG methods. The chemical compositions and morphology of the synthesized materials were investigated by the energy dispersive X‐ray analysis (EDX) and the transmission electron microscopy (TEM). The results reveal that at the reaction time 96 h, ZLDH has the highest crystalinity which was confirmed by the X‐ray diffraction spectra. The calcined samples at 500, 600 and 700 °C for 4 h show that the crystallinity of the nanocomposite improves with the increase of calcination temperature. The photocatalytic activities of synthesized nanocomposites were compared for the degradation of C. I. Basic Blue 3 (BB3) dye under UV illumination in aqueous solution. Among the synthesized nanocomposites, ZnO/MMO calcined at 700 °C shows the highest efficiency towards the removal of dye. The effect of UV illumination on the stability of ZnO in ZnO/MMO nanocomposite and pure ZnO was also investigated. The results showed that the photostability of ZnO in ZnO/MMO nanocomposite is increased compared to the pure ZnO.
Electrochemical Valorisation of Glycerol
Authors: Simões Mário , Baranton Stève , Coutanceau Christophe 
Published: October 2012

AbstractThe worldwide glycerol stocks are increasing; to make the biodiesel industry sustainable economically, this chemical could be used as a secondary primary raw material. Electric energy or hydrogen and added‐value‐chemical cogeneration becomes more and more an important research topic for increasing economical and industrial interests towards electrochemical technologies. Studies on glycerol electrooxidation for fuel or electrolysis cell applications are scarce. The valorisation of glycerol is generally performed by organic chemistry reactions forming, for example, esters, glycerol carbonates, ethers, acetals or ketals. Glycerol oxidation is made up of complex pathway reactions that can produce a large number of useful intermediates or valuable fine chemicals with presently limited market impact due to expensive production processes. Many of these chemical oxidation routes lead to significant amounts of undesired by‐products, and enzymatic processes are limited. Converse to classical heterogeneous processes, electrocatalytic oxidation processes can be tuned by controlling the nature, composition and structure of the electrocatalyts as well as the electrode potential. Such control may lead to very high selectivity and activity, avoiding or limiting product separation steps. The coupling of glycerol oxidation to produce chemicals with the oxygen reduction reaction in a fuel cell or water reduction reaction in an electrolysis cell on Pt‐free catalysts results either in coproduction of electrical energy or hydrogen for energy storage.
Functionalized Graphene for High Performance Lithium Ion Capacitors
Authors: Lee Ji Hoon , Shin Weon Ho , Ryou Myung‐Hyun , Jin Jae Kyu , Kim Junhyung , Choi Jang Wook 
Published: October 2012

AbstractLithium ion capacitors (LICs) have recently drawn considerable attention because they utilize the advantages of supercapacitors (high power) and lithium ion batteries (high energy). However, the energy densities of conventional LICs, which consist of a pair of graphite and activated carbon electrodes, are limited by the small capacities of the activated carbon cathodes. To overcome this limitation, we have engaged urea‐reduced graphene oxide. The amide functional groups generated during the urea reduction facilitate the enolization processes for reversible Li binding, which improves the specific capacity by 37 % compared to those of conventional systems such as activated carbon and hydrazine‐reduced graphene oxide. Utilizing the increased Li binding capability, when evaluated based on the mass of the active materials on both sides, the LICs based on urea‐reduced graphene oxide deliver a specific energy density of approximately 106 Wh kgtotal−1 and a specific power density of approximately 4200 W kgtotal−1 with perfect capacity retention up to 1000 cycles. These values are far superior to those of previously reported LICs and supercapacitors, which suggests that appropriately treated graphene can be a promising electrode material for LICs.
Network‐layer security for the Internet of Things using TinyOS and BLIP
Authors: Granjal Jorge , Monteiro Edmundo , Silva Jorge Sá 
Published: October 2012

SUMMARYThe design of standard communications and security mechanisms for resource‐constrained sensing applications and devices may provide an important contribution for its integration with the Internet and consequently towards the realization of what we nowadays identify as the Internet of Things. This vision will only be realizable if appropriate security mechanisms are available, and in this context we target the design and experimental evaluation of security mechanisms for communications at the network‐layer with sensing devices (smart objects) using the standard IPv6 protocol. Our work proposes and evaluates the usage of new compressed security headers for the network layer with smart objects. We implement and evaluate what is, as far as we know, the first proposal of security at the network layer experimentally evaluated using the TinyOS operating system and its networking stack. As we verify in the course of our evaluation study, various scenarios employing network‐layer secure communications involving smart objects are feasible, particularly when security mechanisms are designed to benefit from cross‐layer interactions that allow the optimization of expensive cryptographic operations. Copyright © 2012 John Wiley & Sons, Ltd.
Performance analysis of MIMO beamforming with imperfect feedback
Authors: Tang Lan , Zhang Xinggan , Bai Yechao , Zhu Pengcheng 
Published: October 2012

SUMMARYThe quality of channel state information at the transmitter (CSIT) is critical to MIMO beamforming systems. However, in practical wireless systems, CSIT suffers from imperfections originating from quantization effects, feedback error and feedback delay. In this paper, we study the impact of feedback error and delay on the symbol error rate of MIMO beamforming systems with finite rate feedback. The feedback channel is modeled as a uniform symmetric channel. We derive an symbol error rate upper bound that is tight for a good beamformer. We also quantify the diversity gain and array gain loss due to the feedback error and delay. The codebook design method that is applicable to the beamforming systems with error or delay feedback is discussed. Both analytical and simulation results show that feedback error and delay will make the system behave badly at high signal‐to‐noise ratios. Copyright © 2012 John Wiley & Sons, Ltd.
Water‐storage capacity controls energy partitioning and water use in karst ecosystems on the Edwards Plateau, Texas
Authors: Heilman James L. , Litvak Marcy E. , McInnes Kevin J. , Kjelgaard James F. , Kamps Ray H. , Schwinning Susanne 
Published: October 2012

ABSTRACTWoody plants are encroaching into grasslands and savannas of the karst Edwards Plateau, but their impacts on climate and hydrology are unclear because of high variability in soil depth and uncertainties about the contribution of water in fractured limestone to the water available to trees. Water use is controlled by available energy (AE) and its partitioning between latent (λE) and sensible (H) heat fluxes. We hypothesized that the partitioning of AE depends on soil depth, with greater depth leading to more λE and less H. We compared energy fluxes of a deep soil savanna with ~50% woody cover dominated by Ashe juniper (Juniperus ashei) and a shallow soil woodland dominated by live oak (Quercus virginiana) and juniper over a 5‐year period, which included periods of unusually high rainfall and severe drought. Although AE was 7% higher in the woodland, λE was about 2% higher at the savanna over the 5‐year study. Site differences in evapotranspiration were maximal during dry periods between rainfall events, suggesting greater storage of water at the savanna site. During periods of high rainfall, the impact of water storage limitations was minimal, and site differences in evapotranspiration were controlled mainly by AE and its partitioning into H. Both sites were characterized by rapid reductions in λE and reciprocal increases in H during drying cycles following rainfall, indicating that neither of these ecosystems had access to easily utilized sources of deep water. Copyright © 2012 John Wiley & Sons, Ltd.