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Nakara Bhawawet, Jeremy B Essner, Durgesh Vinod Wagle, Gary A Baker
Two different ionic liquids comprising the tetrabutylphosphonium cation ([P4444]) paired with the strongly-coordinating anions 6-aminocaproate ([6-AC]) or taurinate ([tau]) were prepared and employed in an aqueous/organic liquid bilayer system to generate nanoscale gold by Au(OH)4- photoreduction. Generally, as the concentration of ionic liquid in the organic phase was increased, the resulting quasi-spherical gold nanoparticles reduced in size and presented less aggregation, leading to marked increases in the catalytic efficiency for 4-nitrophenol reduction using borohydride...
May 23, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Ruizhi Guo, Lihao Liao, Xiaodan Zhao
A suitable oxidative system is crucial to electrophilic selenium catalysis (ESC). This short review offers the overview of recent development in ESC with electrophilic N-F reagents as the oxidants. Several highly selective transformations of alkenes such as allylic or vinylic imidation, pyridination, syn-dichlorination, oxidative cyclization and asymmetric cyclization have been described.
May 19, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Youfu Wang, Shudan Chen, Aiguo Hu
Synthetic polymer chemistry is a fundamental part of polymer science, and highly efficient polymerization reactions are essential for the synthesis of high-performance polymers. Development of new synthetic methods for emerging polymer science is of great importance in this regard. Bergman cyclization is a chemical process in which highly reactive aryl diradicals form from enediyne precursors, having a strong impact in a number of fields including pharmaceutics, synthetic chemistry, and materials science. Diradical intermediates stemming from enediynes can cause DNA cleavage under physiological conditions, leading to the strong cytotoxicity of many naturally occurring enediyne antibiotics...
June 2017: Topics in Current Chemistry (Journal)
Jian An, Charles M Ponthier, Ragna Sack, Jan Seebacher, Michael B Stadler, Katherine A Donovan, Eric S Fischer
Thalidomide and its derivatives lenalidomide and pomalidomide (IMiDs) are effective treatments of haematologic malignancies. It was shown that IMiDs impart gain-of-function properties to the CUL4-RBX1-DDB1-CRBN (CRL4(CRBN)) ubiquitin ligase that enable binding, ubiquitination and degradation of key therapeutic targets such as IKZF1, IKZF3 and CSNK1A1. While these substrates have been implicated as efficacy targets in multiple myeloma (MM) and 5q deletion associated myelodysplastic syndrome (del(5q)-MDS), other targets likely exist...
May 22, 2017: Nature Communications
Z Wojnarowska, E Thoms, B Blanchard, S N Tripathy, P Goodrich, J Jacquemin, J Knapik-Kowalczuk, M Paluch
Modern ionic liquids (ILs) are considered green solvents for the future applications due to their inherited advantages and remarkable transport properties. One of the ubiquitous properties of ILs is their intrinsic ionic conductivity. However, understanding of the super-Arrhenius behavior of the ionic conductivity process at elevated pressure still remains elusive and crucial in glass science. In this work, we investigate the ion transport properties of 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide: [C4mim][NTf2], 1-butylimidazolium bis[(trifluoromethyl)-sulfonyl]imide: [C4Him][NTf2] and 1-butylimidazolium hydrogen sulfate: [C4Him][HSO4] ILs in the supercooled liquid state using dielectric spectroscopy at ambient and high pressure...
May 19, 2017: Physical Chemistry Chemical Physics: PCCP
Yago Nieto, Benigno C Valdez, Sai R Pingali, Roland Bassett, Ruby Delgado, John Nguyen, Nina Shah, Uday Popat, Roy B Jones, Borje S Andersson, Alison Gulbis, Sairah Ahmed, Qaiser Bashir, Simrit Parmar, Krina Patel, Alan Myers, Gabriela Rondon, Robert Z Orlowski, Richard Champlin, Muzaffar Qazilbash
BACKGROUND: High-dose melphalan is of little benefit as a regimen for patients with relapsed or refractory myeloma undergoing an autologous stem-cell transplant (ASCT). The poor performance of single-agent melphalan in this setting prompted us to study a new high-dose combination of infused gemcitabine, busulfan, and melphalan. METHODS: We did a phase 2 trial at the University of Texas MD Anderson Cancer Center (Houston, TX, USA). We enrolled patients with primary refractory or relapsed myeloma who had received treatment with bortezomib, an immunomodulatory drug, or both, or who were receiving a salvage ASCT...
May 15, 2017: Lancet Haematology
Alex Ryan Neale, Sinead Murphy, Peter Goodrich, Christopher Hardacre, Johan Jacquemin
A series of hydrophobic room temperature ionic liquids (ILs) based on ethereal functionalised pyrrolidinium, piperidinium and azepanium cations bearing the bis{(trifluoromethyl)sulfonyl}imide, [TFSI]-, anion were synthesized and characterized. Their physicochemical properties such as density, viscosity and electrical conductivity and thermal properties including phase transition behaviour and decomposition temperature have been measured. All of the ILs showed low melting point, low viscosity and good conductivity and the latter properties have been discussed in terms of the IL fragility, an important electrolyte feature of the transport properties of glassy-forming ILs...
May 18, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
Francesco Nastasi, Giuseppina La Ganga, Sebastiano Campagna, Zois Syrgiannis, Francesco Rigodanza, Stefania Vitale, Antonino Licciardello, Maurizio Prato
Herein, the synthesis and the photophysical and redox properties of a new perylene bisimide (PBI) species (L), bearing two 1,10-phenanthroline (phen) ligands at the two imide positions of the PBI, and its dinuclear Ru(ii) and Os(ii) complexes, [(bpy)2Ru(μ-L)Ru(bpy)2](PF6)4 (Ru2; bpy = 2,2'-bipyridine) and [(Me2-bpy)2Os(μ-L)Os(Me2-bpy)2](PF6)4 (Os2; Me2-bpy = (4,4'-dimethyl)-2,2'-bipyridine), are reported. The absorption spectra of the compounds are dominated by the structured bands of the PBI subunit due to the lowest-energy spin-allowed π-π* transition...
May 18, 2017: Physical Chemistry Chemical Physics: PCCP
Lauren W Veltri, Denái R Milton, Ruby Delgado, Nina Shah, Krina Patel, Yago Nieto, Partow Kebriaei, Uday R Popat, Simrit Parmar, Betul Oran, Stefan Ciurea, Chitra Hosing, Hans C Lee, Elisabet Manasanch, Robert Z Orlowski, Elizabeth J Shpall, Richard E Champlin, Muzaffar H Qazilbash, Qaiser Bashir
BACKGROUND: Despite the introduction of effective, novel agents, the outcome of patients with refractory multiple myeloma remains poor, particularly those who are refractory to both proteasome inhibitors (PIs) and immunomodulatory agents (IMiDs). Limited data are available on the role of autologous hematopoietic stem cell transplantation in this population. METHODS: Patients with refractory myeloma who underwent first autologous hematopoietic stem cell transplantation (auto-HCT) between March 2000 and October 2015 were retrospectively analyzed...
May 17, 2017: Cancer
Mingsheng Xie, Lili Lin, Xiaoming Feng
In this review, the recent developments in catalytic asymmetric inverse-electron-demand hetero-Diels-Alder reaction, which is recognized as one of the most powerful routes to construct highly functionalized and enantioenriched six-membered heterocycles, are described. The article is organized on the basis of different kinds of electron-deficient heterodienes, including α,β-unsaturated ketones/aldehydes, o-benzoquinones, α,β-unsaturated imines, N-aryl imines, o-benzoqinone imides, and other aza-olefins.
May 16, 2017: Chemical Record: An Official Publication of the Chemical Society of Japan ... [et Al.]
François Saint-Dizier, Nigel S Simpkins
The synthesis of the unusual alkaloid concavine, isolated from Clitocybe concava (Basidiomycetae), has been accomplished. The synthetic route features regio- and stereoselective manipulation of polycyclic imide intermediates via enolate substitution and Grignard addition, along with a key bridge-forming step involving a new method for sulfenylative radical cyclisation. The NMR data for synthetic concavine demonstrate that the original data reported for the natural product refer to the derived acetic acid salt, probably formed as an artefact of isolation or purification...
May 1, 2017: Chemical Science
Chelsea L Gustafson, Nicole C Parsley, Hande Asimgil, Hsiau-Wei Lee, Christopher Ahlbach, Alicia K Michael, Haiyan Xu, Owen L Williams, Tara L Davis, Andrew C Liu, Carrie L Partch
The C-terminal transactivation domain (TAD) of BMAL1 (brain and muscle ARNT-like 1) is a regulatory hub for transcriptional coactivators and repressors that compete for binding and, consequently, contributes to period determination of the mammalian circadian clock. Here, we report the discovery of two distinct conformational states that slowly exchange within the dynamic TAD to control timing. This binary switch results from cis/trans isomerization about a highly conserved Trp-Pro imide bond in a region of the TAD that is required for normal circadian timekeeping...
May 18, 2017: Molecular Cell
Wattaka Sitaputra, Dario Stacchiola, James F Wishart, Feng Wang, Jerzy T Sadowski
Charge transport at the interface of electrodes and ionic liquids is critical for the use of the latter as electrolytes. A room-temperature ionic liquid, 1-ethyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide (EMMIM TFSI), is investigated in situ under applied bias voltage with a novel method using low-energy electron and photoemission electron microscopy. Changes in photoelectron yield as a function of bias applied to electrodes provide a direct measure of the dynamics of ion reconfiguration and electrostatic responses of the EMMIM TFSI...
May 12, 2017: Advanced Materials
Leslie-Joana Riwar, Nils Trapp, Bernd Kuhn, François Diederich
Host-guest systems with Rebek imide type receptors and a 2,6-di(isobutyramido)pyridine ligand were employed to investigate substituent effects in parallel-displaced π-π stacking interactions. Changing the intermolecular distance between the para substituent on the aromatic platform of the receptor and the pyridine ring of the guest results in a strongly different substituent effect. With a short ethyne-1,2-diyl spacer between the Rebek imide and the aromatic platform, partial overlap of substituent and guest stabilizes the π-π stacking interactions independent of the electronic nature of the substituent (Wheeler-Houk model)...
May 11, 2017: Angewandte Chemie
R G Waruna Jinadasa, Michael B Thomas, Yi Hu, Francis D'Souza, Hong Wang
A series of β-pyrrole functionalized push-pull porphyrins with amine push groups linked via an ethynylphenyl spacer, and cyclic imide or carboxylic esters as pull groups have been newly synthesized and characterized. The β-pyrrole functionalized ethynylphenyl spacer extends the conjugation of the porphyrin π-system, as reflected by their red-shifted absorbance and fluorescence spectra. The computed structures revealed no steric hindrance between the porphyrin π-system and the β-substituents. The calculated HOMO and LUMO of compounds WJ2 and WJ3 display significant segregation, where the electron density in the HOMO and LUMO is mainly located at the donor component and the acceptor component, respectively...
May 10, 2017: Physical Chemistry Chemical Physics: PCCP
Idaira Pacheco-Fernández, Verónica Pino, Juan H Ayala, Ana M Afonso
The IL-based surfactant octylguanidinium chloride (C8Gu-Cl) was designed and synthetized with the purpose of obtaining a less harmful surfactant: containing guanidinium as core cation and a relatively short alkyl chain. Its interfacial and aggregation behavior was evaluated through conductivity and fluorescence measurements, presenting a critical micelle concentration value of 42.5 and 44.6mmolL(-1), respectively. Cytotoxicity studies were carried out with C8Gu-Cl and other IL-based and conventional surfactants, specifically the analogue 1-octyl-3-methylimidazolium chloride (C8MIm-Cl), and other imidazolium- (C16MIm-Br) and pyridinium- (C16Py-Cl) based surfactants, together with the conventional cationic CTAB and the conventional anionic SDS...
May 1, 2017: Journal of Chromatography. A
Hiroshi Okada, Hiroki Kawakami, Shinobu Aoyagi, Yutaka Matsuo
Organic functionalization of lithium-ion-containing [60]fullerene, Li+@C60, was performed by using diphenyl(diazo)methane as a stable, readily available diazo compound to obtain lithium-ion-encapsulated [5,6]- and [6,6]-diphenylmethano[60]fullerenes, Li+@C61Ph2. The bis(trifluoromethanesulfonyl)imide (TFSI) salts of [5,6]- and [6,6]-Li+@C61Ph2 were successfully separated by using a cation exchange column with eluent containing LiTFSI. Improved separation protocol and high crystallinity of ionic components in less polar solvents enabled separate crystallization of each isomer...
May 10, 2017: Journal of Organic Chemistry
Senlin Gu, Leon Zhu, Claude Mercier, Yongjin Li
Polypropylene (PP)/glass fiber (GF) composites showing excellent antistatic performance were prepared by a simple melt process blending PP with GF and a small amount of organic salts (OSs). Two types of OSs, tribuyl(octyl)phosphonium bis(trifloromethanesulfonyl)imide (TBOP-TFSI) and lithium bis(trifloromethanesulfonyl)imide (Li-TFSI), with equivalent anions were used as antistatic agents for the composites. It was found that the GF and OSs exhibited significant synergistic effects on the antistatic performance as well as the mechanical properties of the composites...
May 16, 2017: ACS Applied Materials & Interfaces
Saad Z Usmani, Joris Diels, Tetsuro Ito, Maneesha Mehra, Imran Khan, Annette Lam
Daratumumab is a human CD38-directed monoclonal antibody approved in the United States as monotherapy for patients with multiple myeloma (MM) who have received ≥3 prior lines of therapy (LOTs), including a proteasome inhibitor (PI) and an immunomodulatory agent (IMiD) or who are double refractory to a PI and an IMiD, and in combination with lenalidomide/dexamethasone or bortezomib/dexamethasone for patients with MM who have received ≥1 prior LOT. This study compared the efficacy of daratumumab monotherapy versus historical controls through adjusted treatment comparison...
May 5, 2017: American Journal of Hematology
Promit Ray, Thomas Vogl, Andrea Balducci, Barbara Kirchner
Solutions of lithium bis(trifluoromethanesulfonyl)imide (LiNTf2), in four different [NTf2](-)-based ionic liquids, are extensively investigated as potential electrolytes for lithium-ion batteries. Solvation of the [Li](+) ions in the ionic liquids and its impact on their physicochemical properties are studied herein with the aid of molecular dynamics simulations. The cationic components of the investigated liquids were systematically varied so as to individually evaluate effects of specific structural changes; increase in ring size, the addition of an alkyl chain and absence of an acidic proton, on the solvation and mobility of the [Li](+) cations...
May 12, 2017: Journal of Physical Chemistry. B
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