bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxyfunctionalization of the Remote C−H Bonds of Aliphatic Amines by Decatungstate Photocatalysis
Authors: Schultz Danielle M. , Lévesque François , DiRocco Daniel A. , Reibarkh Mikhail , Ji Yining , Joyce Leo A. , Dropinski James F. , Sheng Huaming , Sherry Benjamin D. , Davies Ian W. 
Published: October 2017

AbstractAliphatic amines, oxygenated at remote positions within the molecule, represent an important class of synthetic building blocks to which there are currently no direct means of access. Reported herein is an efficient and scalable solution that relies upon decatungstate photocatalysis under acidic conditions using either H2O2 or O2 as the terminal oxidant. By using these reaction conditions a series of simple and unbiased aliphatic amine starting materials can be oxidized to value‐added ketone products. Lastly, NMR spectroscopy using in situ LED‐irradiated samples was utilized to monitor the kinetics of the reaction, thus enabling direct translation of the reaction into flow.
Synthesis of Anisotropic Hydrogels and Their Applications
Authors: Sano Koki , Ishida Yasuhiro , Aida Takuzo 
Published: October 2017

AbstractOwing to their water‐rich structures, which are similar to those of biological tissues, hydrogels have long been regarded as promising scaffolds for artificial tissues and organs. However, in terms of the structural anisotropy, most synthetic hydrogels are substantially different from biological systems. Synthetic hydrogels are usually composed of randomly oriented three‐dimensional polymer networks whereas biological systems adopt anisotropic structures with hierarchically integrated building units. Such anisotropic structures often play essential roles in biological systems to exhibit particular functions. In this context, anisotropic hydrogels provide an entry point for exploring biomimetic applications of hydrogels. Reflecting these aspects, an increasing number of studies on anisotropic hydrogels have been reported recently. This Minireview highlights the use and perspectives of these anisotropic hydrogels, particularly focusing on their preparation, structures, and applications.
Living Supramolecular Polymerization of a Perylene Bisimide Dye into Fluorescent J‐Aggregates
Authors: Wagner Wolfgang , Wehner Marius , Stepanenko Vladimir , Ogi Soichiro , Würthner Frank 
Published: October 2017

AbstractThe self‐assembly of a new perylene bisimide (PBI) organogelator with 1,7‐dimethoxy substituents in the bay position affords non‐fluorescent H‐aggregates at high cooling rates and fluorescent J‐aggregates at low cooling rates. Under properly adjusted conditions, the kinetically trapped “off‐pathway” H‐aggregates are transformed into the thermodynamically favored J‐aggregates, a process that can be accelerated by the addition of J‐aggregate seeds. Spectroscopic studies revealed a subtle interplay of π–π interactions and intra‐ and intermolecular hydrogen bonding for monomeric, H‐, and J‐aggregated PBIs. Multiple polymerization cycles initiated from the seed termini demonstrate the living character of this chain‐growth supramolecular polymerization process.
HAp‐encapsulated γ‐Fe2O3‐supported dual acidic heterogeneous catalyst for highly efficient one‐pot synthesis of benzoxanthenones and 3‐pyranylindoles
Authors: Kheirkhah Leila , Mamaghani Manouchehr , Yahyazadeh Asieh , Mahmoodi Nosrat Ollah 
Published: October 2017

A novel method is reported for the synthesis of benzoxanthenone and 3‐pyranylindole derivatives via one‐pot three‐component reactions using a newly synthesized HAp‐encapsulated γ‐Fe2O3‐supported dual acidic heterogeneous catalyst, as a reusable and highly efficient nanocatalyst. In this protocol the use of the nanocatalyst provided a green, useful and rapid method to generate products in short reaction times (4–20 min) and in excellent yields (87–96%). The paramagnetic nature of the catalyst provided a simple, trouble‐free and facile approach for the separation of the catalyst by applying an external magnet, and it could be used in eight cycles without significant loss in catalytic efficiency.
Cobalt(II)–metformin complexes containing α‐diimine/α‐diamine as auxiliary ligand: DNA binding properties
Authors: Vasantha P. , Sathish Kumar B. , Shekhar B. , Anantha Lakshmi P.V. 
Published: October 2017

The cobalt(II) complexes [Co(Cl)2(met)(o‐phen)] (1), [Co(Cl)2(en)(met)] (2) and [Co(Cl)2(met)(opda)] (3) (met = metformin, o‐phen = ortho‐phenanthroline, en = ethylenediamine, opda = ortho‐phenylenediamine) were synthesized and characterized using liquid chromatography–mass spectrometry, elemental analysis, molar conductance measurements, thermal analysis, infrared spectroscopy, magnetic moment measurements, electronic spectroscopy and X‐ray diffraction. The metal centre was found to be in an octahedral geometry. UV–visible absorption, fluorescence and viscosity measurements were conducted to assess the interaction of the complexes with calf thymus DNA. The complexes showed absorption hyperchromism in UV–visible spectra with DNA. The binding constants from UV–visible absorption studies were 1.38 × 105, 2.1 × 105 and 3.1 × 105 M−1 for 1, 2 and 3, respectively, and Stern–Volmer quenching constants from fluorescence studies were 0.146, 0.176 and 0.475, respectively. Viscosity measurements revealed that the binding of the complexes with DNA could be surface binding, mainly due to groove binding. The activities of the complexes in DNA cleavage decrease in the order 3 > 2 > 1. The complexes were docked into DNA topoisomerase II using Discovery Studio 2.1 software.
Sustainable chitosan/starch composite material for stabilization of palladium nanoparticles: Synthesis, characterization and investigation of catalytic behaviour of Pd@chitosan/starch nanocomposite in Suzuki–Miyaura reaction
Authors: Baran Talat , Yılmaz Baran Nuray , Menteş Ayfer 
Published: October 2017

We fabricated a green chitosan/starch composite as support material for stabilization of palladium nanoparticles for the first time. The chemical structure of the sustainable palladium nanocomposite was investigated using various techniques. Characterization studies showed that the average dimensions of the palladium nanocomposite ranged between 16 and 21 nm. The synthesized palladium nanocomposite was employed in the synthesis of a series of biphenyl compounds via Suzuki–Miyaura cross‐coupling reactions with an unconventional technique. All coupling reactions were conducted in very short reaction time and excellent biphenyl yields were obtained in the presence of the nanocomposite. The palladium catalyst was tolerant to a wide range of functional groups. We also investigated the recyclability and reusability of the palladium nanocomposite, and found that it could be used for seven successive cycles.
Cu(II) immobilized on guanidinated epibromohydrin‐functionalized γ‐Fe2O3@TiO2 (γ‐Fe2O3@TiO2‐EG‐Cu(II)): A highly efficient magnetically separable heterogeneous nanocatalyst for one‐pot synthesis of highly substituted imidazoles
Authors: Nejatianfar Mahdi , Akhlaghinia Batool , Jahanshahi Roya 
Published: October 2017

A simple, efficient and eco‐friendly procedure has been developed using Cu(II) immobilized on guanidinated epibromohydrin‐functionalized γ‐Fe2O3@TiO2 (γ‐Fe2O3@TiO2‐EG‐Cu(II)) for the synthesis of 2,4,5‐trisubstituted and 1,2,4,5‐tetrasubstituted imidazoles, via the condensation reactions of various aldehydes with benzil and ammonium acetate or ammonium acetate and amines, under solvent‐free conditions. High‐resolution transmission electron microscopy analysis of this catalyst clearly affirmed the formation of a γ‐Fe2O3 core and a TiO2 shell, with mean sizes of about 10–20 and 5–10 nm, respectively. These data were in very good agreement with X‐ray crystallographic measurements (13 and 7 nm). Moreover, magnetization measurements revealed that both γ‐Fe2O3@TiO2 and γ‐Fe2O3@TiO2‐EG‐Cu(II) had superparamagnetic behaviour with saturation magnetization of 23.79 and 22.12 emu g−1, respectively. γ‐Fe2O3@TiO2‐EG‐Cu(II) was found to be a green and highly efficient nanocatalyst, which could be easily handled, recovered and reused several times without significant loss of its activity. The scope of the presented methodology is quite broad; a variety of aldehydes as well as amines have been shown to be viable substrates. A mechanism for the cyclocondensation reaction has also been proposed.
New Ni(II), Pd(II) and Pt(II) complexes coordinated to azo pyrazolone ligand with a potent anti‐tumor activity: Synthesis, characterization, DFT and DNA cleavage studies
Authors: Bakr Eman A. , Al‐Hefnawy Gad B. , Awad Mohamed K. , Abd‐Elatty Hossam H. , Youssef Mohamed S. 
Published: October 2017

The absolute necessity to fight some class of tumor is perceived as serious health concerns, so the discovery and development of effective anticancer agents are urgently needed. (E)‐4‐((2‐hydroxyphenyl)diazenyl)‐3‐phenyl‐1H‐pyrazol‐5(4H)‐one, HL, and its Ni(II), Pd(II) and Pt(II) complexes were synthesized and the biological activity was evaluated for antitumor, antioxidant and antimicrobial activity as well as DNA cleavage. Their structures were assigned depending on the elemental analysis, conductivity, magnetic moment, spectral measurements (IR, 1HNMR, mass and UV–Vis) and thermal analysis. 3D molecular modeling using DFT method confirmed that the geometrical structures agree well with the suggested experimental ones. The antitumor activity was evaluated against four different cell lines using MTT assay. The ligand HL showed a potent cytotoxic activity compared to 5‐fluorouracil as a reference drug. For metal complexes, the order of activity was: Pd(II) > Ni(II) > Pt(II). A remarkable antioxidant activity for the ligand HL was recorded. It was higher than that of the metal complexes. Results of antimicrobial experiments revealed that all compounds were moderate to highly active against selected bacterial strains but inactive as antifungal except Pd(II) which showed a moderate antifungal activity. Gel electrophoresis showed insignificant nucleases activity for the ligand or its metal complexes even in the presence of H2O2 providing protection of DNA from damage. The antitumor activity of our compounds may be not due to DNA cleavage but may be referred to a mechanism similar to that of 5‐fluorouracil which interfere with DNA replication. The present work suggests the use of this ligand in the design and development of new anticancer drugs.
New anthracene based Schiff base ligands appended Cu(II) complexes: Theoretical study, DNA binding and cleavage activities
Authors: Gubendran Ammavasai , Kumar Gujuluva Gangatharan Vinoth , Kesavan Mookkandi Palsamy , Rajagopal Gurusamy , Athappan Periakaruppan , Rajesh Jegathalaprathaban 
Published: October 2017

New anthracene based Schiff base ligands L1 and H(L2), their Cu(II) complexes [Cu(L1)Cl2] (1) and [Cu(L2)Cl] (2), (where L1 = N1,N2‐bis(anthracene‐9‐methylene)benzene‐1,2‐diamine, L2 = (2Z,4E)‐4‐(2‐(anthracen‐9‐ylmethyleneamino)phenylimino)pent‐2‐en‐2‐ol) have been prepared and characterized by elemental analysis, NMR, FAB‐mass, EPR, FT‐IR, UV–Vis and cyclic voltammetry. The electronic structures and geometrical parameters of complexes 1 and 2 were analyzed by the theoretical B3LYP/DFT method. The interaction of these complexes 1 and 2 with CT‐DNA has been explored by using absorption, cyclic voltammetric and CD spectral studies. From the electronic absorption spectral studies, it was found that the DNA binding constants of complexes 1 and 2 are 8.7 × 103 and 7.0 × 104 M−1, respectively. From electrochemical studies, the ratio of DNA binding constants K+/K2+ for 2 has been estimated to be >1. The high binding constant values, K+/K2+ ratios more than unity and positive shift of voltammetric E1/2 value on titration with DNA for complex 2 suggest that they bind more avidly with DNA than complex 1. The inability to affect the conformational changes of DNA in the CD spectrum is the definite evidences of electrostatic binding by the complex 1. It can be assumed that it is the bulky anthracene unit which sterically inhibits these complexes 1 and 2 from intercalation and thereby remains in the groove or electrostatic. The complex 2 hardly cleaves supercoiled pUC18 plasmid DNA in the presence of hydrogen peroxide. The results suggest that complex 2 bind to DNA through minor groove binding.
Optical coherence tomography guided carotid artery stent procedure: technique and potential applications
Authors: Dohad Suhail , Zhu Alexander , Krishnan Sandeep , Wang Frances , Wang Serena , Cox Justin , Henry Timothy D. 
Published: October 2017

AbstractObjectivesTo (1) present a guide on how to perform optical coherence tomography (OCT) in carotid artery stenting (CAS), to (2) highlight several instructive cases illustrating OCT‐guidance as an interventional strategy, and to (3) present the largest case‐series of OCT‐guided CAS performed in North America, demonstrating its feasibility as an imaging modality in this setting.BackgroundOCT is an intravascular imaging method that captures images with an axial resolution 10 times higher than intravascular ultrasound. OCT has proven to be a useful modality in coronary angiography and may have similar applications in evaluating carotid atherosclerotic disease.MethodsWe compared our experience in CAS utilizing OCT (40 patients) versus that of CAS without OCT guidance (52 patients).ResultsNo strokes or deaths occurred in either group postprocedurally or at 12 months. Fluoroscopy time was reduced in the OCT arm (14 ± 1 vs. 16 ± 1 min). Postprocedural creatinine levels were identical (1 ± 0 mg/dl, P = 0.96). Procedure time (96 ± 8 vs. 80 ± 3 min, P = 0.06) and contrast use (94 ± 4 vs. 83 ± 4 ml, P = 0.05) was slightly elevated in the OCT arm.ConclusionsWe established a standardized protocol to consistently obtain OCT images that helped guide interventional decision‐making during CAS. OCT imaging in the carotids requires a higher contrast load and prolongs procedure time. However, it can be performed without significant increases in fluoroscopy time or negatively affecting renal function. There were no negative safety signals in this pilot study.
Transcoronary pacing to assess myocardial viability prior to percutaneous coronary intervention: Pilot study to assess feasibility
Authors: O'Neill James , Hogarth Andrew J. , Pearson Ian , Law Hannah , Bowes Robert , Kidambi Ananth , Wheatcroft Stephen , Sivananthan U. Mohanaraj , Tayebjee Muzahir H. 
Published: October 2017

AbstractBackgroundThe assessment of myocardial viability is crucial before percutaneous coronary intervention (PCI) is carried out to ensure that the patient will gain benefit. Trans‐coronary pacing (TCP) has previously been used to pace myocardium but may also provide information on myocardial viability.MethodsPatients with a single, significant coronary stenosis requiring PCI were recruited. They underwent a cardiac MRI to assess myocardial viability. Prior to PCI, a coronary guidewire was used to measure pacing threshold, impedance, and R‐wave amplitude in different myocardial segments to determine any association between the electrical parameters and myocardial viability.ResultsEight patients were recruited and six patients underwent intervention. Pacing sensitivity did not demonstrate statistically significant differences between normal and scarred myocardium. Impedance demonstrated a mean of 304.8 ± 74.0 Ω in normal myocardium (NM), 244.1 ± 66.6 Ω in <50% myocardial scar (MS), and 222.3 ± 33.8 Ω in ≥50% MS. Pacing threshold demonstrated a mean of 1.960 ± 1.226 V in NM, 5.009 ± 2.773 V in <50% MS, and 3.950 ± 0.883 V in ≥50% MS. For both impedance and threshold, there was a significant difference among the groups (P = 0.12 and P = 0.002, respectively), and post hoc Tukey's pairwise comparison demonstrated significant differences between NM and scarred myocardium. No significant differences were found between <50% MS and ≥50% MS.ConclusionsImpedance and pacing threshold, measured during TCP, can be used to differentiate between normal myocardium and scarred myocardium. Further research is needed to determine whether TCP can discriminate between viable and nonviable myocardium.
A Bifunctional Fluorogenic Rhodamine Probe for Proximity‐Induced Bioorthogonal Chemistry
Authors: Werther Philipp , Möhler Jasper S. , Wombacher Richard 
Published: October 2017

AbstractBioorthogonal reactions have emerged as a versatile tool in life sciences. The inverse electron demand Diels–Alder reaction (DAinv) stands out due to the availability of reactants with very fast kinetics. However, highly reactive dienophiles suffer the disadvantage of being less stable and prone to side reactions. Herein, we evaluate the extent of acceleration of rather unreactive but highly stable dienophiles by DNA‐templated proximity. To this end, we developed a modular synthetic route for a novel bifunctional fluorogenic tetrazine rhodamine probe that we used to determine the reaction kinetics of various dienophiles in a fluorescence assay. Under proximity‐driven conditions the reaction was found to be several orders of magnitude faster, and we observed almost no background reaction when proximity was not induced. This fundamental study identifies a minimally sized fluorogenic tetrazine dienophile reactant pair that has potential to be generally used for the visualization of biomolecular interactions with temporal and spatial resolution in living systems.
Substitution Reactions at DippBIAN Supported Fluoroantimony Cations Yielding Cyanoantimony and Azidoantimony Cations
Authors: Suter Riccardo , Frazee Christopher , Burford Neil , McDonald Robert , Ferguson Michael J. 
Published: October 2017

AbstractThis work presents new cationic coordination complexes of antimony with the 1,2‐bis[(2,6‐diisopropylphenyl)imino]acenaphthene (DippBIAN) ligand system. The fluoroantimony complexes [SbF(DippBIAN)][OTf]2 and [SbF2(DippBIAN)][OTf] have been successfully isolated and characterized. The fluorine substituent in the Lewis acidic complex [SbF(DippBIAN)][OTf]2 can be selectively replaced without degradation of the Sb‐DippBIAN interaction to give the first dicationic azido and cyano derivatives, [Sb(CN)(DippBIAN)][OTf]2 and [Sb(N3)(DippBIAN)][OTf]2, which have been isolated and structurally characterized.
Alkyl and Aryl Thiol Addition to [1.1.1]Propellane: Scope and Limitations of a Fast Conjugation Reaction
Authors: Bär Robin M. , Kirschner Stefan , Nieger Martin , Bräse Stefan 
Published: October 2017

AbstractHerein the addition of different thiols to the strained carbon–carbon bond of [1.1.1]propellane (1) is reported. The reaction pathway was investigated, addition reactions with substituted thiols, hydrogen sulfide and protected cysteine were performed, and further modifications of the products were verified. The clean reaction proceeds by a radical chain process, which was confirmed by different deuterium labelling experiments. It shows high functional‐group tolerance, since halo‐, hydroxy‐, methoxy‐, carboxy‐, amino‐ and nitro‐substituted thiols could be added to 1 with few by‐products in 16–90 % yield. Oxidation of the products allows tuning of the polarity and subsequent reactions of the products. The click‐type reaction proceeds even faster with selenols, as was shown in a proof of concept. Thiol addition to 1 offers a facile tool for surface modification, conjugation and tuning of hydrophilicity in bio‐ and medicinal chemistry.
Synthesis of Spirocyclic Pyrrolidines: Advanced Building Blocks for Drug Discovery
Authors: Chalyk Bohdan A. , Butko Maryna V. , Yanshyna Oksana O. , Gavrilenko Konstantin S. , Druzhenko Tetiana V. , Mykhailiuk Pavel K. 
Published: October 2017

AbstractInvited for the cover of this issue is the group of Pavel K. Mykhailiuk at the Taras Shevchenko National University of Kyiv and Enamine Ltd. The image depicts spirocyclic pyrrolidine—a novel building block for drug discovery. Read the full text of the article at 10.1002/chem.201702362.
Gold‐Doping of Double‐Crown Pd Nanoclusters
Authors: Chen Jishi , Liu Liren , Liu Xu , Liao Lingwen , Zhuang Shengli , Zhou Shiming , Yang Jinlong , Wu Zhikun 
Published: October 2017

AbstractDouble‐crown Ni, Pd, or Pt nanoclusters have attracted extensive interests due to their aesthetic structure and intriguing properties. However, their doping by other metals remains unknown until now. Herein, Pd4(PET)8 and Pd5(PET)10 (PET: SCH2CH2Ph) were successfully doped with gold and the doped nanoclusters were characterized by using multiple techniques such as mass spectrometry and X‐ray crystallography. It is revealed that in the doping not one but two gold atoms replace one Pd with the other double‐crown structure essentially unchanged, and the gold‐doping results in the blue‐shift of the maximum visible absorption, the increase of optical energy gap and the reduction of anti‐aromaticity of monometal Pd nanoclusters. Importantly, it is found that Au4Pd2(PET)8 nanocluster bears chirality originating from not only the helixed Au4Pd2S8 framework, but also unanimous R or S configuration of sulfur atoms in the enantiomer. For the latter chirality origin, it was not previously reported or proposed. Au4Pd2(PET)8 reported here also represents the smallest chiral bimetal nanocluster so far to the best of our knowledge. This work advances one step toward both the tailoring of group 10 metal nanoclusters by doping and the understanding of chirality origin for metal nanoclusters.
Aerosol‐Synthesis of Porous Catalyst Particles with Tailored Pores and Tunable Metal Particle Size
Authors: Röhrbein Jannis , Arias Aurina Martínez , Weber Alfred P. 
Published: October 2017

AbstractDie Herstellung von porösen geträgerten Katalysatoren mit fein einstellbaren Struktureigenschaften spielt in der heterogenen Katalyse eine große Rolle in der Erforschung von Reaktionsabläufen und Mechanismen. Das Zusammenspiel von nanoskaligen Poren und Aktivkomponenten bietet dabei die Möglichkeit der Optimierung von Reaktionen im Hinblick auf Ausbeute und Selektivität. Gängige Synthesemethoden sind oftmals in der Variationsbreite limitiert. Im Rahmen dieser Arbeit wird ein einfacher und gut skalierbarer Aerosol‐Syntheseweg für die Herstellung nanoskaliger Katalysatoren für die Fischer‐Tropsch‐Synthese aufgezeigt.
Cover Picture: Rapid Detection of Sildenafil Drugs in Liquid Nutraceuticals Based on Surface‐Enhanced Raman Spectroscopy Technology (Chin. J. Chem. 10/2017)
Authors: Zhao Hang , Hasi Wuliji , Bao Lin , Han Siqingaowa , Sha Xuanyu , Sun Jia , Lou Xiutao , Lin Dianyang , Lv Zhiwei 
Published: October 2017

The cover picture shows a rapid detection of sildenafil drugs in liquid nutraceuticals based on surface‐enhanced Raman spectroscopy technology. A detailed attribution analysis by density functional theory (DFT) was used to guide specific experiments. The Raman signals were obtained from a silver colloid (Ag col) substrate, and they increased in the presence of the mineral salt, potassium iodide (KI). These methods detected sildenafil in aqueous solutions as low as 1 µg/mL with high signal uniformity (RSD = 3.77%). Raman technology detected low contents of sildenafil drugs in liquid nutraceuticals, not in solid samples. Therefore, SERS technology has great potential for on‐site and real‐time detection of illegal drugs in water and in liquid nutraceuticals. More details are discussed in the article by Hasi et al. on page 1522–1528.
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