bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: A Facile Synthetic Route to 2‐Trifluoromethyl‐Substituted Polyfunctionalized Chromenes and Chromones.
Authors: Wen Lele , Zhang Honghai , Lin Hao , Shen Qilong , Lu Long 
Published: May 2012

AbstractNEt3‐mediated reaction of salicylaldehydes (I) with (Z)‐butenoate (II) provides an easy access to 2‐trifluoromethylchromenols (III), which can readily be oxidized to corresponding chromones (IV).
ChemInform Abstract: CuO Nanoparticles: An Efficient and Recyclable Nanocatalyst for the Rapid and Green Synthesis of 3,4‐Dihydropyrano[c]chromenes.
Authors: Mehrabi Hossein , Kazemi‐Mireki Maryam 
Published: May 2012

AbstractCuO‐nanoparticles are described as recyclable heterogeneous catalyst for the three‐component synthesis of the title compounds (IV).
ChemInform Abstract: Features of the α‐Azolyl‐2‐hydroxyacetophenones Reaction with Chloroacetyl Chloride.
Authors: Shokol T. V. , Gorbulenko N. V. , Khilya V. P. 
Published: May 2012

AbstractFor unknown reasons, the cyclization of title acetophenones proceeds only in the presence of thiazole rings.
ChemInform Abstract: 1,3‐Dichloro‐tetra‐n‐butyl‐distannoxane: A New Application for Catalyzing the Direct Substitution of 9H‐Xanthen‐9‐ol at Room Temperature.
Authors: Liu Ling‐yan , Zhang Yan , Huang Kai‐meng , Chang Wei‐xing , Li Jing 
Published: May 2012

AbstractTin‐catalyzed direct substitution reactions of xanthenol (II) with indoles (I) afford xanthenylindole derivatives (III) in high yields.
ChemInform Abstract: Stereoselective Piperidine Synthesis Through Oxidative Carbon—Hydrogen Bond Functionalizations of Enamides.
Authors: Brizgys Gediminas J. , Jung Hyung Hoon , Floreancig Paul E. 
Published: May 2012

AbstractIn the presence of DBU, N‐vinyl carbamates, sulfonamides, and amides that contain pendent π‐nucleophiles such as allylsilane, enolsilane, propargylsilane, and enol acetate, give the piperidines within minutes.
ChemInform Abstract: Facile One‐Pot Synthesis of Polysubstituted Quinolines under Solvent‐Free Conditions Using Sulfamic Acid as a Reusable Catalyst.
Authors: Zhang Min , Xiong Biao , Yang Wei , Kumar D. N. T. , Ding Yu‐Qiang 
Published: May 2012

AbstractThe reaction proceeds regioselectively in the case of disubstituted anilines such as (VI) or β‐naphthylamine (IV).
ChemInform Abstract: Synthesis of Annulated Pyridines by Intramolecular Inverse‐Electron‐Demand Hetero‐Diels—Alder Reaction under Superheated Continuous Flow Conditions.
Authors: Martin Rainer E. , Morawitz Falk , Kuratli Christoph , Alker Andre M. , Alanine Alexander I. 
Published: May 2012

AbstractThe reaction of various pyrimidine alkynes proceeds with the expulsion of cyanides and provides facile access to the novel annulated pyridine building blocks.
ChemInform Abstract: Three‐Component Spiro Heterocyclization of 1H‐Pyrrole‐2,3‐dione by the Action of 3‐Arylamino‐1H‐inden‐1‐ones.
Authors: Dmitriev M. V. , Silaichev P. S. , Aliev Z. G. , Maslivets A. N. 
Published: May 2012

AbstractA previously inaccessible spiro[diindeno[1,2‐b:2′,1′‐e]pyridine‐11,3′‐pyrrole] heterocyclic system is obtained.
ChemInform Abstract: A Synthesis of Dihydroimidazo[5,1‐a]isoquinolines Using a Sequential Ugi—Bischler—Napieralski Reaction Sequence.
Authors: Seganish W. Michael , Bercovici Ana , Ho Ginny D. , Loozen Hubert J. J. , Timmers Cornelis M. , Tulshian Deen 
Published: May 2012

AbstractThe two‐step sequence is optimized to give fair yields of the biologically interesting title compounds (V).
ChemInform Abstract: Isoxazoles Incorporated N‐Substituted Decahydroquinolines: A Precursor to the Next Generation Antimicrobial Drug.
Authors: Babu Mariappan , Pitchumani Kasi , Ramesh Penugonda 
Published: May 2012

AbstractA simple access to N‐substituted decahydroisoxazoloquinolines (IV) with substituents at position 3 and 4 is achieved from readily available substrates in appreciable yields.
ChemInform Abstract: One‐Pot Synthesis of 2,6‐Diamino‐4‐sulfonamidopyrimidines from Sulfonyl Azides, Terminal Alkynes and Cyanoguanidine.
Authors: Yavari Issa , Nematpour Manijeh , Ghazanfarpour‐Darjani Majid 
Published: May 2012

AbstractAddition of copper acetylides to sulfonyl azides generates ketenimines which are readily trapped by cyanoguanidine to yield the pyrimidines.
ChemInform Abstract: Green Synthesis of Quinazolinone Derivatives Catalyzed by Iodine in Ionic Liquid.
Authors: Wang Shu‐Liang , Yang Ke , Yao Chang‐Sheng , Wang Xiang‐Shan 
Published: May 2012

AbstractIodine‐catalyzed cyclization of o‐aminobenzamides (I) with triethyl orthoformate (II) or triphosgene (IV) proceeds smoothly in ionic liquid as solvent to afford quinazolinones (III) and (IV) in high yields.
ChemInform Abstract: Facile and Efficient Synthesis of 3,10‐Disubstituted‐bis‐1,2,4‐triazolo[4,3‐a][3′,4′‐c]quinoxalines Using Copper Dichloride as an Oxidant.
Authors: Aggarwal Ranjana , Sumran Garima , Yadav Mamta , Anju Anju 
Published: May 2012

AbstractCopper dichloride is a nontoxic, inexpensive, and readily available reagent, which offers a general access to the synthesis of bis‐triazoloquinoxalines, which are not obtainable by use of iodobenzene diacetate.
ChemInform Abstract: First Synthesis of 4‐Aminopyrido[2′,3′:4,5]furo[3,2‐d]pyrimidines.
Authors: Loidreau Yvonnick , Marchand Pascal , Dubouilh‐Benard Carole , Nourrisson Marie‐Renee , Duflos Muriel , Besson Thierry 
Published: May 2012

AbstractThe novel precursor (II) is prepared following the procedure published for its 6‐bromo analogue.
ChemInform Abstract: Highly Efficient and Broad‐Scope Protocol for the Preparation of 7‐Substituted 6‐Halopurines via N9‐Boc‐Protected 7,8‐Dihydropurines.
Authors: Kotek Vladislav , Tobrman Tomas , Dvortak Dalimil 
Published: May 2012

AbstractIt is demonstrated that a Boc‐protecting group is suitable for the synthesis of a variety of 7,9‐disubstituted derivatives which can be readily deprotected and oxidized to 7‐substituted purines in excellent overall yields.
ChemInform Abstract: Desulfurization of Pyrido[3′,2′:4,5]thieno[2,3‐f]pyrrolo[1,2‐a][1,4]diazepines.
Authors: Red'kin V. M. , Stroganova T. A. , Vasilin V. K. , Krapivin G. D. 
Published: May 2012

AbstractThe thieno[2,3‐b]pyridine fragment in (I) undergoes desulfurization in the presence of activated Raney nickel.
ChemInform Abstract: Rapid Synthesis of Benzodiazepines by Ring Expansion of Aziridines with Anthranilic Acids by Using a Grinding Technique.
Authors: Singh Atul K. , Yadav Lal Dhar S. 
Published: May 2012

AbstractA direct synthesis of potentially pharmaceutically relevant benzo‐1,4‐diazepines is developed by LiBr‐catalyzed reaction of anthranilic acids with aziridines.
ChemInform Abstract: Preparation of Chiral Multifunctional Thiourea—Phosphanes and Synthesis of Chiral Allylic Phosphites and Phosphane Oxides Through Asymmetric Allylic Substitution Reactions of Morita—Baylis—Hillman Carbonates.
Authors: Deng Hong‐Ping , Shi Min 
Published: May 2012

AbstractThe reactions apply chiral multifunctional thiourea‐phosphane catalyst (TPB) to afford allylic phosphites and phosphane oxides in high yields and enantioselectivities.
ChemInform Abstract: Synthesis of Novel Heterocyclic Systems 3,9‐Dihydro‐2H‐[1,3]selenazolo[3,2‐a]benzimidazol‐4‐ium Derivatives.
Authors: Borisov A. V. , Matsulevich Zh. V. , Osmanov V. K. , Borisova G. N. 
Published: May 2012

AbstractThe novel fused selenazole heterocycles (V) and (VII) are formed both diastereo‐ and regioselectively.
ChemInform Abstract: Unusual Reactivity of Dimethylsulfoxonium Methylide with Esters.
Authors: Leggio Antonella , De Marco Rosaria , Perri Francesca , Spinella Mariagiovanna , Liguori Angelo 
Published: May 2012

AbstractThe title reaction affords the corresponding free acids after an acidic work‐up through an ester hydrolysis mechanism.
ChemInform Abstract: Rapid Access to Polycyclic Indolines Related to the Stephacidin Alkaloids Using a Radical Cascade.
Authors: Simpkins Nigel , Pavlakos Ilias , Male Louise 
Published: May 2012

AbstractThis radical cascade reaction initiated from sulfur‐substituted diketopiperazine (I) affords indolines as key stepping stones to avrainvillamide, stephacidin B, and their bioactive analogues.
ChemInform Abstract: Design, Synthesis, Antiviral and Cytostatic Evaluation of Novel Isoxazolidine Nucleotide Analogues with a 1,2,3‐Triazole Linker.
Authors: Piotrowska Dorota G. , Balzarini Jan , Glowacka Iwona E. 
Published: May 2012

AbstractReplacing the furanose ring by an isoxazolidine system and introduction of a triazole linker between isoxazolidine and the nucleobase or another aromatic function afford the title analogues (V) and (VI).
ChemInform Abstract: Four New Stilbenoids from the Orchids Coelogyne ochracea and Coelogyne cristata
Authors: Majumder P. L. , Bandyopadhyay Saswati , Pal Suparna 
Published: May 2012

Abstractisolation and structure of ochracinone (Ia), ochracinanthrone (Ib), coeloginone (Ic) and coeloginanthrone (Id)
ChemInform Abstract: Colloidal CIGS and CZTS Nanocrystals: A Precursor Route to Printed Photovoltaics
Authors: Akhavan Vahid A. , Goodfellow Brian W. , Panthani Matthew G. , Steinhagen Chet , Harvey Taylor B. , Stolle C. Jackson , Korgel Brian A. 
Published: May 2012

AbstractReview: CIGS: Cu(In1‐xGax)Se2, CZTS: Cu2ZnSnS4; 63 refs.
ChemInform Abstract: Recent Patents on Oligonucleotide Synthesis and Gene Synthesis
Authors: Yu Tingsheng , Bao Xiao , Piao Wenxian , Peng Jingli , Li Wei , Yang Cui , Xing Meng , Zhang Yiliu , Qi Jinhuan , Xu Lei , et al. et al. 
Published: May 2012

AbstractReview: 37 refs.
Synthesis of a Heparan Sulfate Mimetic Library Targeting FGF and VEGF via Click Chemistry on a Monosaccharide Template
Authors: Liu Ligong , Li Caiping , Cochran Siska , Jimmink Shane , Ferro Vito 
Published: May 2012

AbstractA disulfated methyl 6‐azido‐6‐deoxy‐α‐D‐mannopyranoside template was used as a core structure for binding to the angiogenic growth factors FGF‐1, FGF‐2, and VEGF. The core structure was diversified in a rapid, parallel manner by employing the CuI‐catalyzed Huisgen azide–alkyne cycloaddition (“click”) reaction. The diversity was further extended by incorporating a Swern oxidation–Wittig reaction sequence on a click adduct of propargyl alcohol. Thus, the sulfated core was linked by various spacers to selected hydrophobic or polar motifs, which were designed to probe the protein surface surrounding the cationic heparan sulfate binding sites of the growth factors in order to improve affinity and selectivity. The affinities of the compounds for the growth factors were measured by surface plasmon resonance solution affinity assays. A lead compound was identified with micromolar binding affinity toward both FGF‐1 and VEGF (Kd=84 and 49 μM, respectively) and good selectivity over FGF‐2 (29‐ and 51‐fold, respectively).
A robust and efficient valve model based on resistive immersed surfaces
Authors: Astorino Matteo , Hamers Jeroen , Shadden Shawn C. , Gerbeau Jean‐Frédéric 
Published: May 2012

SUMMARYA procedure for modeling the heart valves is presented. Instead of modeling complete leaflet motion, leaflets are modeled in open and closed configurations. The geometry of each configuration can be defined, for example, from in vivo image data. This method enables significant computational savings compared with complete fluid–structure interaction and contact modeling, while maintaining realistic three‐dimensional velocity and pressure distributions near the valve, which is not possible from lumped parameter modeling. Leaflets are modeled as immersed, fixed surfaces over which a resistance to flow is assigned. On the basis of local flow conditions, the resistance values assigned for each configuration are changed to switch the valve between open and closed states. This formulation allows for the pressure to be discontinuous across the valve. To illustrate the versatility of the model, realistic and patient‐specific simulations are presented, as well as comparison with complete fluid–structure interaction simulation. Copyright © 2012 John Wiley & Sons, Ltd.
Large Deviations for Brownian Intersection Measures
Authors: König Wolfgang , Mukherjee Chiranjib 
Published: May 2012

AbstractWe consider p independent Brownian motions in
\input amssym ${\Bbb R}^d$. We assume that p ≥ 2 and p (d − 2) < d. Let ℓt denote the intersection measure of the p paths by time t, i.e., the random measure on \input amssym ${\Bbb R}^d$
that assigns to any measurable set \input amssym $A \subset {\Bbb R}^d$
the amount of intersection local time of the motions spent in A by time t. Earlier results of X. Chen derived the logarithmic asymptotics of the upper tails of the total mass \input amssym $\ell _t \left({{\Bbb R}^d } \right)$
as t → ∞. In this paper, we derive a large‐deviation principle for the normalized intersection measure t−pℓt on the set of positive measures on some open bounded set \input amssym $B \subset {\Bbb R}^d$
as t → ∞ before exiting B. The rate function is explicit and gives some rigorous meaning, in this asymptotic regime, to the understanding that the intersection measure is the pointwise product of the densities of the normalized occupation times measures of the p motions. Our proof makes the classical Donsker‐Varadhan principle for the latter applicable to the intersection measure.A second version of our principle is proved for the motions observed until the individual exit times from B, conditional on a large total mass in some compact set
$U \subset B$. This extends earlier studies on the intersection measure by König and Mörters. © 2012 Wiley Periodicals, Inc.
Divalent Europium Nanocrystals: Controllable Synthesis, Properties, and Applications
Authors: Wang Chuanxi , Xu Lin , Li Xiangwei , Lin Quan 
Published: May 2012

AbstractMagnetic and luminescent bifunctional divalent europium nanocrystals (Eu2+ NCs) are a promising class of novel advanced materials that have various applications in magneto‐optic devices, catalysis, bioimaging, and solar cells. In the past few decades, much work has been carried out to study the synthesis, properties, and applications of Eu2+ NCs. The aim of this Minireview is to present the progress in preparing Eu2+ NCs based on the reported research, by describing the advantages and disadvantages of the synthesis methods. The morphologies and size are controlled through adjusting the experimental conditions. Eu2+ NCs show superior magnetic and luminescence properties simultaneously. Self‐assembly and doping with other ions are important routes to improve their magnetic and luminescence properties. Their applications in magneto‐optic devices are discussed. Some difficulties and challenges in the fabrication of Eu2+ NCs are discussed, such as water‐soluble Eu2+ NCs and tunable luminescence in the whole visible region.
Calixarene‐Based Surfactants: Conformational‐Dependent Solvation Shells for the Alkyl Chains
Authors: Basílio Nuno , Garcia‐Rio Luis 
Published: May 2012

AbstractThermodynamic parameters obtained from studying the micellization of amphiphilic p‐sulfonatocalix[n]arenes were correlated with the alkyl chain length and with the number of monomeric units (n) in the calix[n]arene structure. The micellization Gibbs free energy (Δ${G{{{\rm o}\hfill \atop {\rm M}\hfill}}}$) becomes more negative upon increasing the alkyl chain length of the p‐sulfonatocalix[4]arene. This is in agreement with the trend generally observed for other surfactants. However, the Δ${G{{{\rm o}\hfill \atop {\rm M}\hfill}}}$ value for transferring one CH2 group from the bulk aqueous medium to the micelle [Δ${G{{{\rm o}\hfill \atop {\rm M}\hfill}}}$(CH2)] is lower than the value generally observed for single‐chain surfactants, suggesting the existence of intramolecular interactions between the alkyl chains of the free unimers. On the other hand, the critical micelle concentration (cmc; per alkyl chain unit) increased with the increasing number of monomeric units. These results are explained on the basis of the conformation adopted by the calixarene in the bulk solution. The calix[4]arene derivatives are preorganized into the cone conformation, which is favorable for the formation of globular aggregates. The calix[6]arene and calix[8]arene derivatives do not adopt cone conformations. Changing these conformations to the more favorable cone conformer in the aggregates implies an energetic cost that contributes to making Δ${G{{{\rm o}\hfill \atop {\rm M}\hfill}}}$ less efficient. In the case of the calix[6]arene derivative this energetic cost is enthalpic, whereas in the case of the octamer it is both enthalpic and entropic. Both the Δ${G{{{\rm o}\hfill \atop {\rm M}\hfill}}}$(CH2) value and the change in heat capacity (ΔC${{\rm p}{{{\rm o}\hfill \atop {\rm M}\hfill}}}$) seem to indicate that for the cone calix[4]arene derivatives all alkyl chains are solvated by the same hydration shell, whereas in the case of the highly flexible calix[8]arene derivative each alkyl chain is individually hydrated.
Structural Characteristics of Graphane‐Type C and BN Nanostructures by Periodic Local MP2 Approach
Authors: Tanskanen Jukka T. , Maschio Lorenzo , Karttunen Antti J. , Linnolahti Mikko , Pakkanen Tapani A. 
Published: May 2012

AbstractThe structural characteristics of fully‐hydrogenated carbon and boron nitride mono‐ and multilayer slabs, together with nanotubes derived from the slabs, are investigated mainly by means of periodic local second‐order Møller–Plesset perturbation (LMP2) calculations and the results are compared with Hartree–Fock (HF), density functional theory (DFT), and dispersion function‐augmented DFT (DFT‐D) obtained ones. The investigated systems are structurally analogous to (111) and (110) slabs of diamond, where the hydrogenated (111) slab of diamond corresponds to the experimentally known graphane. Multilayering of monolayers and nanotubes is energetically favorable at the LMP2 level for both C and BN, while HF and DFT are not able to reproduce this behavior for CH systems. The work highlights the importance of utilizing methods capable of properly describing weak interactions in the investigation of dispersively‐bound systems such as the multilayered graphanes and the corresponding nanotubes.
The Nature of Chemical Bonds from PNOF5 Calculations
Authors: Matxain Jon M. , Piris Mario , Uranga Jon , Lopez Xabier , Merino Gabriel , Ugalde Jesus M. 
Published: May 2012

AbstractNatural orbital functional theory (NOFT) is used for the first time in the analysis of different types of chemical bonds. Concretely, the Piris natural orbital functional PNOF5 is used. It provides a localization scheme that yields an orbital picture which agrees very well with the empirical valence shell electron pair repulsion theory (VSEPR) and Bent’s rule, as well as with other theoretical pictures provided by valence bond (VB) or linear combination of atomic orbitals–molecular orbital (LCAO‐MO) methods. In this context, PNOF5 provides a novel tool for chemical bond analysis. In this work, PNOF5 is applied to selected molecules that have ionic, polar covalent, covalent, multiple (σ and π), 3c–2e, and 3c–4e bonds.
Spiral Intramolecular Charge Transfer and Large First Hyperpolarizability in Möbius Cyclacenes: New Insight into the Localized π Electrons
Authors: Zhong Rong‐Lin , Xu Hong‐Liang , Su Zhong‐Min , Li Zhi‐Ru , Sun Shi‐Ling , Qiu Yong‐Qing 
Published: May 2012

AbstractMuch effort has been devoted to investigating the unusual properties of the π electrons in Möbius cyclacenes, which are localized in a special region. However, the localized π electrons are a disadvantage for applications in optoelectronics, because intramolecular charge transfer is limited. This raises the question of how the intramolecular charge transfer of a Möbius cyclacene with clearly localized π electrons can be enhanced. To this end, [8]Möbius cyclacene ([8]MC) is used as a conjugated bridge in a donor–π‐conjugated bridge–acceptor (D–π–A) system, and NH2‐6‐[8]MC‐10‐NO2 exhibits a fascinating spiral charge‐transfer transition character that results in a significant difference in dipole moments Δμ between the ground state and the crucial excited state. The Δμ value of 6.832 D for NH2‐6‐[8]MC‐10‐NO2 is clearly larger than that of 0.209 D for [8]MC. Correspondingly, the first hyperpolarizability of NH2‐6‐[8]MC‐10‐NO2 of 12 467 a.u. is dramatically larger than that of 261 a.u. for [8]MC. Thus, constructing a D–π–A framework is an effective strategy to induce greater spiral intramolecular charge transfer in MC although the π electrons are localized in a special region. This new insight into the properties of π electrons in Möbius cyclacenes may provide valuable information for their applications in optoelectronics.
Polypyridyl Complexes of Ruthenium(II): Stabilization of G‐quadruplex DNA and Inhibition of Telomerase Activity
Authors: Liu Du , Liu Yanan , Wang Chuan , Shi Shuo , Sun Dongdong , Gao Feng , Zhang Qianling , Liu Jie 
Published: May 2012

AbstractTwo ruthenium(II) complexes [Ru(phen)2(tip)](ClO4)2 (1) and [Ru(bpy)2(tip)](ClO4)2 (2; phen=1,10‐phenanthroline, bpy=2,2’‐bipyridine, tip=2‐thiophenimidazo[4,5‐f][1,10]phenanthroline) were synthesized and characterized by elemental analysis, 1H NMR spectroscopy, and electrospray ionization‐mass spectrometry to explore the role of metal complexes as novel telomeric quadruplex stabilizers. The different quadruplex binding properties of these compounds were evaluated by absorption and emission analyses, circular dichroism spectroscopy, fluorescence resonance energy transfer (FRET) melting assay, NMR spectroscopy, and molecular modeling. The results show that both complexes can well induce and stabilize different G‐quadruplex structures using a 1:1 [quadruplex]/[complex] binding mode ratio. Complex 1 exhibits higher interaction ability at 1.43×106 M−1 binding affinity and superior G‐quadruplex selectivity over duplex DNA through multiple interaction (mainly intercalating) with the G‐quadruplex at the 3’‐terminal face. Furthermore, polymerase chain reaction (PCR)‐stop assay, electrophoretic mobility shift assay, telomerase repeat amplification protocol, and MTT assay demonstrate that complex 1 not only can stabilize dimer forms of the G‐quadruplex at low concentrations but also exhibit better inhibitory activity for telomerase and cancer cells. The results suggest that complex 1 may be a potential telomerase inhibitor for cancer chemotherapy.
Investigation of Copper Corrosion Inhibition with Frequency‐Dependent Alternating‐Current Scanning Electrochemical Microscopy
Authors: Santana Juan José , Pähler Maike , Schuhmann Wolfgang , Souto Ricardo M. 
Published: May 2012

AbstractAlternating current scanning electrochemical microscopy (AC‐SECM) is used to investigate the inhibition of copper corrosion by four potential inhibitors, namely benzotriazole (BTAH), 5‐methyl‐benzotriazole (MBTAH), 2‐mercaptobenzimidazole (MBI), and ethyl xanthate (EX). It is shown that the formation of inhibitor films on the metal can be followed from the decrease of the substrate’s local electrochemical activity associated with the formation of inhibitor‐containing surface layers. Sensitive imaging can be performed that accounts for changes in electrochemical activity of the modified surfaces, as well as for their corrosive attack from the environment. AC‐SECM is shown to be a powerful technique for the investigation of corrosion processes.