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Shunsuke Chiba - One of the best experts on this subject based on the ideXlab platform.
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leaving group ability in nucleophilic aromatic amination by sodium hydride Lithium Iodide composite
Synthesis, 2020Co-Authors: Jia Hao Pang, Ryo Takita, Kohei Watanabe, Shunsuke ChibaAbstract:The methoxy group is generally considered as a poor leaving group for nucleophilic substitution reactions. This work verified the superior ability of the methoxy group in nucleophilic amination of arenes mediated by the sodium hydride and Lithium Iodide through experimental and computational approaches.
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nucleophilic amination of methoxypyridines by a sodium hydride Iodide composite
Chemical Communications, 2018Co-Authors: Jia Hao Pang, Atsushi Kaga, Shunsuke ChibaAbstract:A new protocol for nucleophilic amination of methoxypyridines and their derivatives was developed using sodium hydride (NaH) in the presence of Lithium Iodide (LiI). The method offers a concise access to various aminopyridines which are potentially of medicinal interest.
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dearylation of arylphosphine oxides using a sodium hydride Iodide composite
Chemical Communications, 2018Co-Authors: Ciputra Tejo, Jia Hao Pang, Derek Yiren Ong, Masanobu Uchiyama, Ryo Takita, Shunsuke ChibaAbstract:A new protocol for the dearylation of arylphosphine oxides was developed using sodium hydride (NaH) in the presence of Lithium Iodide (LiI). The transient sodium phosphinite could be functionalized with a range of electrophiles in a one-pot fashion.
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nucleophilic amination of methoxy arenes promoted by a sodium hydride Iodide composite
Angewandte Chemie, 2017Co-Authors: Atsushi Kaga, Masanobu Uchiyama, Ryo Takita, Hirohito Hayashi, Hiroyuki Hakamata, Shunsuke ChibaAbstract:A method for the nucleophilic amination of methoxy arenes was established by using sodium hydride (NaH) in the presence of Lithium Iodide (LiI). This method offers an efficient route to benzannulated nitrogen heterocycles. Mechanistic studies showed that the reaction proceeds through an unusual concerted nucleophilic aromatic substitution.
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amide directed c h sodiation by a sodium hydride Iodide composite
Angewandte Chemie, 2017Co-Authors: Yinhua Huang, Guo Hao Chan, Shunsuke ChibaAbstract:A new protocol for amide-directed ortho and lateral C-H sodiation is enabled by sodium hydride (NaH) in the presence of either sodium Iodide (NaI) or Lithium Iodide (LiI). The transient organosodium intermediates could be transformed into functionalized aromatic compounds.
Tadashi Uemura - One of the best experts on this subject based on the ideXlab platform.
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solubilities for the two ternary systems water Lithium bromide Lithium Iodide and water Lithium chloride Lithium nitrate at various temperatures
Journal of Chemical & Engineering Data, 1993Co-Authors: Shigeki Iyoki, Shozo Iwasaki, Yutaka Kuriyama, Tadashi UemuraAbstract:The analyses of absorption refrigeration and heat pump systems need extensive thermodynamic information such as heat capacities, heats of mixing, vapor pressures, solubilities, densities, viscosities, and surface tensions for working medium plus absorbent systems. Solubilities for the water + Lithium bromide + Lithium Iodide (salt mole ratio 4:1) and the water + Lithium chloride + Lithium nitrate (salt model ratio 2.8:1) systems were measured by means of visual polythermal method from 277.75 to 415.15 K and from 284.85 to 351.75 K, respectively. The transition point for the water + Lithium bromide + Lithium Iodide system existed at 65.3 mass % salts and 293.85 K and at 54.2 mass % salts and 295.75 K for the water + Lithium chloride + Lithium nitrate system. Two solid-liquid phases for these two ternary systems were stable below and above the individual transition point. Two least-squares regression equations as a function of absolute temperatures were obtained from the individual measured solubility data for these two ternary systems. The maximum and average absolute deviations of the calculated values from the individual experimental data were 0.29 and 0.10 % for the water + Lithium chloride + Lithium nitrate system, respectively.
Ying Yang - One of the best experts on this subject based on the ideXlab platform.
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Lithium Iodide effect on the electrochemical behavior of agarose based polymer electrolyte for dye sensitized solar cell
Electrochimica Acta, 2011Co-Authors: Weijia Wang, Xueyi Guo, Ying YangAbstract:Abstract The effect of Lithium Iodide (LiI: 0–85 wt%) on the electrochemical behavior of agarose-based polymer electrolytes for dye-sensitized solar cells (DSSC) was investigated. Fourier Transform Infrared Spectroscopy (FTIR) and scanning electronic microscopy (SEM) were employed to characterize the interactions between polymer matrix and salt and the morphology of the agarose electrolytes, respectively. From the AC impedance spectra study, it was determined that the conduction behavior of the agarose-based polymer electrolyte matches the “salt-in-polymer” like behavior of low LiI content (0–25 wt%) and “polymer-in-salt” like behavior of high LiI content (25–85 wt%). Detailed analysis of characteristic electrochemical processes occurring in DSSC with these agarose electrolytes was also obtained by employing the EIS technique. The impedance spectra showed that the electron lifetime of DSSC was shortened with increasing LiI concentration, while the charge transfer resistance and charge recombination resistance were reduced when LiI concentration was increased.
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Effect of Lithium Iodide Addition on Poly(ethylene oxide)−Poly(vinylidene fluoride) Polymer-Blend Electrolyte for Dye-Sensitized Nanocrystalline Solar Cell
Journal of Physical Chemistry B, 2008Co-Authors: Ying Yang, Sujuan Wu, Hongwei Han, Bolei Chen, Conghua Zhou, Sheng Xu, Jing Zhang, Wei Liu, Xingzhong ZhaoAbstract:The effect of Lithium Iodide concentration on the conduction behavior of poly(ethylene oxide)−poly(vinylidene fluoride) (PEO−PVDF) polymer-blend electrolyte and the corresponding performance of the dye-sensitized solar cell (DSSC) were studied. The conduction behavior of these electrolytes was investigated with varying LiI concentration (10−60 wt % in polymer blend) by impedance spectroscopy. A “polymer-in-salt” like conduction behavior has been observed in the high salt concentration region. The transition from “salt-in-polymer” to “polymer-in-salt” conduction behavior happened at the salt content of 23.4 wt %, which is much lower than 50 wt % as generally reported. The electrolyte shows the highest ionic conductivity (∼10−3 S cm−1) at the salt concentration above 23.4 wt %. From the evaluation of salt effect on the performances of corresponding DSSC, we find that increasing LiI concentration leads to increased short-circuit photocurrent density (Jsc) caused by enhanced I3− diffusion up to an LiI content...
Joan Bosch - One of the best experts on this subject based on the ideXlab platform.
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nucleophilic addition of 1 acetylindole enolates to pyridinium salts stereoselective formal synthesis of geissoschizine and akagerine via 1 4 dihydropyridines
Journal of Organic Chemistry, 1999Co-Authors: Lluisa M Bennasar, Juanmiguel Jimenez, Bernat Vidal, And Bilal A Sufi, Joan BoschAbstract:Addition of the enolate derived from 1-acetylindole (3) to pyridinium salt 4b followed by acid-induced cyclization of the resulting 1,4-dihydropyridine 5b in the presence of Lithium Iodide gives tetracyclic 3,7-methano[1,4]diazonino[1,2-a]indole 6b, which has subsequently been elaborated into the (E)-ethylidene derivative 7b. From this compound is reported a stereocontrolled route to (±)-geissoschizine, involving closure of C ring by Pummerer reaction, methanolysis of the resulting pentacyclic lactam 12, and desulfurization. A similar synthetic sequence starting from the enolate of 3 and 2-fluoropyridinium salt 15b gives access to the pentacyclic dilactam 2, which had previously been converted to (±)-akagerine through opening of the piperidone (D) ring.
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the effect of Lithium Iodide on the acid promoted cyclization of 4 1 indolylcarbonyl methyl 1 4 dihydropyridines
Tetrahedron Letters, 1996Co-Authors: Lluisa M Bennasar, Juanmiguel Jimenez, Bilal A Sufi, Joan BoschAbstract:Abstract 1,4-Dihydropyridines 3 resulting from the addition of the enolate derived from 1-acetylindole ( 1 ) to pyridinium salts 2 do not undergo cyclization under the usual acidic conditions, but do satisfactorily cyclize to the tetracyclic derivatives 4 by treatment with TsOH in the presence of Lithium Iodide.
A K Arof - One of the best experts on this subject based on the ideXlab platform.
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effect of Lithium Iodide on the performance of dye sensitized solar cells dssc using poly ethylene oxide peo poly vinyl alcohol pva based gel polymer electrolytes
Optical Materials, 2018Co-Authors: L P Teo, T S Tiong, M H Buraidah, A K ArofAbstract:Abstract In this work, different concentrations of Lithium Iodide (LiI) have been added to the gel polymer electrolyte (GPE) containing PEO and PVA in equal ratio, tetrabutylammonium Iodide (TBAI), ethylene carbonate (EC), dimethyl sulfoxide (DMSO) and iodine crystals (I2). The effect of introducing Lithium Iodide (LiI) into PEO-PVA blended GPE system having TBAI has been investigated in terms of optical, electrical, thermal and electrochemical characteristics. Fourier transform infrared (FTIR) spectroscopy has been carried out to study the interaction of LiI with the GPEs. The GPE without LiI showed the highest conductivity of 5.50 mS cm−1 at room temperature. With the incorporation of LiI, decrement in conductivity was observed. Dye-sensitized solar cells (DSSCs) with configuration FTO/TiO2/N3-dye/GPE/Pt/FTO have been fabricated and tested under white light of intensity 100 mW cm−2. The DSSC made of GPE with 1.34 wt% LiI exhibited highest efficiency, η of 6.26%.
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structural studies and ionic conductivity of Lithium Iodide Lithium tungstate solid electrolytes
Ionics, 2002Co-Authors: Azizah Hanom Ahmad, A K ArofAbstract:Solid mixtures of calcined Lithium Iodide - Lithium tungstate (LiI -Li2WO4) have been found to be potential solid electrolytes for practical applications with high conductivities of about 10−3 S·cm−1 at room temperature. The highest ionic conductivity was recorded for the sample containing 20 wt.-% of Lithium Iodide. The ionic conductivity was related to the structure of the material using X-ray diffraction (XRD) and infrared techniques (FTIR). These experiments confirm the evidence of interaction between LiI and Li2WO4. FTIR spectroscopy revealed the existence of a band at 1505 cm−1 which is formed as a result of this LiI -Li2WO4 interaction. The new phase acts as a conducting pathway for the ions to migrate through the material. Lithium ionic conduction was confirmed by measuring the transference number by Wagner's polarization technique. The ionic transference number of this solid electrolyte was found to be 1 within the limits of error.