- Synthesis of organosilicon polymers by using the Lewis-acid-catalyzed trans-allylsilylation of alkynes
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The HfCl4 catalyzed polymerization of allyl(4-ethynylphenyl) dimethylsilane (1a) proceeded smoothly to give poly[dimethyl-(1,4-pentadienyl) phenylsilane] (2a), and the HfCl4 catalyzed reaction of 1-allyl-2-(4-ethynyphenyl)-1,1,2,2-tetramethyldisilane (1b) afforded poly[1,1,2,2-tetramethyl-1-(1,4-pentadienyl)-2-phenyldisilane] (2b). These polymerization reactions proceeded via the stereoselective trans-allylsilylation of the 4-ethynyl group attached to the aromatic ring.
- Asao, Naoki,Tomeba, Hisamitsu,Yamamoto, Yoshinori
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- Synthesis, in-situ membrane preparation, and good gas permselectivity of insoluble poly(substituted acetylene)s loosely cross-linked with short and soft siloxane and silanol linkages
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Insoluble but membrane-formable poly(substituted acetylene)s loosely cross-linked by short and soft Si–O–Si and SiOH---(OH)Si linkages have been synthesized from the corresponding monomers having one or two SiOH groups. These monomers have been polymerized in homogeneous systems to produce homogeneous polymer solutions in toluene. The resulting solutions were cast on polytetrafuluoroethylene sheets followed by evaporation of the solvent to give tough and flexible membranes which were completely insoluble. The membranes showed good oxygen and carbon oxide permselectivity and their plots in PO2 vs PO2/PN2 graph exceeded the 1991 Robeson's upper bound and very close to the 2008 Robeson's upper bound. The excellent selectivity are caused by enhancement of diffusion selectivity by the soft network structure which can create small pores (i.e., ultramicro pores) based on the short linkages. No drop in permeability may be due to the soft Si–O–Si and SiOH---(OH)Si linkages. In addition no change in PO2 and PO2/PN2 by aging was observed.
- Wang, Jianjun,Aoki, Toshiki,Kaneko, Takashi,Teraguchi, Masahiro
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- Sulfo-Phenylated Polyphenylenes Containing Sterically Hindered Pyridines
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We systematically investigated the effect of incorporating a sterically hindered pyridyl group into a sulfo-phenylated polyphenylene to control the polymer's physicochemical properties through acid-base interactions. Homopolymers with similar molecular weights and comparable structures that vary by only one atom (N- vs C-) per repeat unit along the polymer chain were prepared. Compared to a non-pyridyl reference membrane, incorporation of a pyridyl group improves the oxidative stability against free radicals, increases the elongation at break to 55% (from 37%), and enhances the thermal stability to 326 °C (from 246 °C). In an accelerated fuel cell degradation test, polymeric membranes containing the sterically encumbered pyridyl unit exhibited exceptional stability (0.16 mV h-1 degradation rate over 1000 h) and retained ~80% of their peak power density over this time.
- Xu, Shaoyi,Adamski, Michael,Killer, Miho,Schibli, Eric M.,Frisken, Barbara J.,Holdcroft, Steven
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- Donor–acceptor–acceptor-based non-fullerene acceptors comprising terminal chromen-2-one functionality for efficient bulk-heterojunction devices
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Two simple semiconducting donor–acceptor–acceptor (D–A1–A) modular, small molecule, non-fullerene electron acceptors, 2-(4-(diphenylamino)phenyl)-3-(4-((2-oxo-2H-chromen-3-yl)ethynyl)phenyl)buta-1,3-diene-1,1,4,4-tetracarbonitrile (P2) and 2-(4-(3,3-dicyano-1-(4-(diphenylamino)phenyl)-2-(4-((2-oxo-2H-chromen-3-yl)ethynyl)phenyl)allylidene)cyclohexa-2,5-dien-1-ylidene)malononitrile (P3), were designed, synthesized and characterized for application in solution-processable bulk-heterojunction solar cells. The optoelectronic and photovoltaic properties of P2 and P3 were directly compared with those of a structural analogue, 3-((4-((4-(diphenylamino)phenyl)ethynyl)phenyl)ethynyl)-2H-chromen-2-one (P1), which was designed based on a D–A format. All of these new materials comprised an electron rich triphenylamine (TPA) donor core (D) and electron deficient chromen-2-one terminal core (A). In the simple D–A system, TPA and chromenone were the terminal functionalities, whereas in the D–A1–A system, tetracyanoethylene (TCNE) and tetracyanoquinodimethane (TCNQ) derived functionalities were incorporated as A1 units by keeping the D/A units constant. The inclusion of A1 was primarily done to induce cross-conjugation within the molecular backbone and hence to generate low band gap targets. The physical and optoelectronic properties were characterized by ultraviolet–visible (UV–Vis), thermogravimetric analysis, photo-electron spectroscopy in air and cyclic voltammetry. These new materials exhibited broadened absorption spectra, for instance panchromatic absorbance in case of P3, excellent solubility and thermal stability, and energy levels matching those of the conventional and routinely used donor polymer poly(3-hexyl thiophene) (P3HT). Solution-processable bulk-heterojunction devices were fabricated with P1, P2 and P3 as non-fullerene electron acceptors. Studies on the photovoltaic properties revealed that the best P3HT: P3-based device showed an impressive enhanced power conversion efficiency of 4.21%, an increase of around two-fold with respect to the efficiency of the best P3HT: P1-based device (2.28%). Our results clearly demonstrate that the D–A1–A type small molecules are promising non-fullerene electron acceptors in the research field of organic solar cells.
- Srinivasa Rao, Pedada,Gupta, Akhil,Bhosale, Sidhanath V.,Bilic, Ante,Xiang, Wanchun,Evans, Richard A.,Bhosale, Sheshanath V.
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- Redox Properties of Ferrocenyl Ene-diynyl-Bridged Cp?(dppe)M-C≡C-1,4-(C6H4) Complexes
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The complexes FcCH=C{1,4-C≡C-C6H4-C≡CM(dppe)Cp?}2 (Fc = ferrocenyl (FeCp(η-C5H4-); M = Fe (1), Ru (2)) were prepared from FcCH=C{1,4-C≡C-C6H4-C≡CSiMe3}2 (3) via a desilylation/metalation protocol in good (2; 65%) to excellent (1; 97%) yield. The iron compound 1 could also be prepared in a stepwise fashion by desilylation of 3 to give FcCH=C{1,4-C≡C-C6H4-C≡CH}2 (4), reaction with FeCl(dppe)Cp? to give the vinylidene complex FcCH=C{1,4-C≡C-C6H4-CH=C=Fe(dppe)Cp?}2](PF6)2 (5(PF6)2; 65%), and deprotonation. The cyclic voltammograms of 1 and 2 are characterized by an initial oxidation wave resulting from the overlap of two closely spaced oxidation processes, the potentials of which are sensitive to the identity of M, and a subsequent, one-electron-oxidation wave. Thus, while the dications 12+ and 22+ could be prepared by oxidation with 2 equiv of ferrocenium hexafluorophosphate and isolated as the PF6- salts 1(PF6)2 and 2(PF6)2 at low temperature, the monocations 1+ and 2+ could only be detected and studied as comproportionated mixtures of 1, 1(PF6), 1(PF6)2 and 2, 2(PF6), 2(PF6)2. A combination of EPR spectroscopy, IR and NIR spectroelectrochemistry, and DFT quantum chemical calculations reveal subtle distinctions in the electronic structures of 1(PF6)n and 2(PF6)n (n = 0-2). The HOMOs of 1 and 2 are more heavily distributed over the metal-diethynylbenzene arm trans to the ferrocenyl moiety. While one-electron oxidation of 1 gives 1(PF6), in which the spin density is similarly distributed along the branch of the molecule trans to the ferrocenyl group, the spin density in 2(PF6) is more extensively, but not fully, delocalized. Further analysis of the ESR, NIR, and IR spectra reveals that charges are essentially localized in 1(PF6) and 1(PF6)2 on the IR time scale, but ground-state exchange between the Fe(dppe)Cp? moieties can take place via the ferrocenyl moiety on the slower ESR time scale. For 2(PF6) and 2(PF6)2, optical charge transfer processes between the ferrocenyl moiety and the organometallic branches can also be observed, consistent with the increased coupling between the Ru(dppe)Cp? and Fc moieties that are linked by a linear conjugation pathway through the bridging-ligand backbone.
- Makhoul, Rim,Gluyas, Josef B. G.,Vincent, Kevin B.,Sahnoune, Hiba,Halet, Jean-Fran?ois,Low, Paul J.,Hamon, Jean-René,Lapinte, Claude
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- Impact of deboronation on the electronic characteristics ofcloso-o-carborane: intriguing photophysical changes in triazole-appended carboranyl luminophores
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5-Phenyl-1,2,4-triazole-appendedcloso- (CB1andCB2) andnido-o-carboranyl (nido-CB1andnido-CB2) compounds were prepared and fully characterized using multinuclear NMR spectroscopy and elemental analysis. The solid-state molecular structures of bothcloso-compounds were analyzed by X-ray crystallography. Although thecloso-compounds exhibited dual emissive patterns in the rigid state (in THF at 77 K), which were assignable to a π-π* local excitation (LE)-based emission (λem=ca. 380 nm) on the triazole moieties and to an intramolecular charge transfer (ICT)-based emission (ca. 460 nm) in which theo-carborane units acted as the acceptor (A), at 298 K in THF, the LE-based emission dominated. In contrast, thenido-compounds exhibited an intensive emission originating from ICT transitions in which theo-carborane units reversibly acted as the donor (D). In particular, the positive solvatochromic effects of bothnido-compounds and the results of theoretical calculations for theo-carboranyl compounds supported the electronic role of theo-carboranyl unit in each compound. Investigation of the radiative decay mechanism of thecloso- andnido-compounds using their quantum efficiency (Φem) and decay lifetime (τobs) suggested that the ICT-based radiative decay ofnido-compounds occurred more efficiently than the LE-based decay ofcloso-compounds. These results implied that emission from thecloso-compounds was drastically enhanced by the deboronation reaction upon exposure to an increasing concentration of fluoride anions, and finally became similar to the emission color (sky-blue) of thenido-compounds.
- Kim, Mingi,Im, Sehee,Ryu, Chan Hee,Lee, Seok Ho,Hong, Ju Hyun,Lee, Kang Mun
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- Synthesis of silicon-containing unsaturated polymers by hydrosilylation reaction. Photophysical studies
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Silicon-containing unsaturated polymers have been synthesized using the Pt(acac)2-catalyzed photoactivated hydrosilylation of alkynes. These polymers fluoresce at 360 nm when excited at 270 nm due to the π-conjugated vinylphenyl segment in the polymer chain. The polymers have excellent solubility in several organic solvents.
- Wang, Fei,Kaafarani, Bilal R.,Neckers, Douglas C.
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- Iodonium Cation-Pool Electrolysis for the Three-Component Synthesis of 1,3-Oxazoles
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The synthesis of 1,3-oxazoles from symmetrical and unsymmetrical alkynes was realized by an iodonium cation-pool electrolysis of I2 in acetonitrile with a well-defined water content. Mechanistic investigations suggest that the alkyne reacts with the acetonitrile-stabilized I+ ions, followed by a Ritter-type reaction of the solvent to a nitrilium ion, which is then attacked by water. The ring closure to the 1,3-oxazoles released molecular iodine, which was visible by the naked eye. Also, some unsymmetrical internal alkynes were tested and a regioselective formation of a single isomer was determined by two-dimensional NMR experiments.
- Sattler, Lars E.,Hilt, Gerhard
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supporting information
p. 605 - 608
(2020/12/07)
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- Au(I) Catalyzed Synthesis of Densely Substituted Pyrazolines and Dihydropyridines via Sequential Aza-Enyne Metathesis/6π-Electrocyclization
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A gold(I) autotandem catalysis protocol is reported for the de novo synthesis of densely substituted pyrazolines and dihydropyridines from the corresponding imine derivatives in a highly regioselective fashion via a one-pot aza-enyne metathesis/6π-electrocyclization sequence. The substituents on the nitrogen atom of the imine perfectly control the reaction pathways from the pivotal 1-azabutadiene intermediate; thus, carbazates were converted into pyrazolines via 6π-electrocyclization of α,β-unsaturated hydrazones, while aryl imines provided dihydropyridines via 6π-electrocyclization of 3-azahexatrienes.
- Sugimoto, Kenji,Kosuge, Shuto,Sugita, Takae,Miura, Yuka,Tsuge, Kiyoshi,Matsuya, Yuji
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supporting information
p. 3981 - 3985
(2021/05/26)
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- Decarboxylation-triggered homo-Nazarov cyclization of cyclic enol carbonates catalyzed by rhenium complex
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Decarboxylative homo-Nazarov cyclization catalyzed by a Lewis acid was achieved using a cyclic enol carbonate bearing a cyclopropane moiety as a substrate. Various substrates were converted into the corresponding multi-substituted cyclohexenones in good yieldsviadecarboxylation, followed by 6-membered ring formation involving cyclopropane-ring-opening.
- Kimaru, Natsuki,Komatsuki, Keiichi,Saito, Kodai,Yamada, Tohru
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supporting information
p. 6133 - 6136
(2021/06/30)
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- Ynonylation of Acyl Radicals by Electroinduced Homolysis of 4-Acyl-1,4-dihydropyridines
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Herein we report the conversion of 4-Acyl-1,4-dihydropyridines (DHPs) into ynones under electrochemical conditions. The reaction proceeds via the homolysis of acyl-DHP under electron activation. The resulting acyl radicals react with hypervalent iodine(III) reagents to form the target ynones or ynamides in acceptable yields. This mild reaction condition allows wider functionality tolerance that includes halides, carboxylates, or alkenes. The synthetic utility of this methodology is further demonstrated by the late-stage modification of complex molecules.
- Luo, Xiaosheng,Wang, Ping
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supporting information
p. 4960 - 4965
(2021/07/20)
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- Synthesis and Photochemical Application of Hydrofluoroolefin (HFO) Based Fluoroalkyl Building Block
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A novel fluoroalkyl iodide was synthesized on multigram scale from refrigerant gas HFO-1234yf as cheap industrial starting material in a simple, solvent-free, and easily scalable process. We demonstrated its applicability in a metal-free photocatalytic ATRA reaction to synthesize valuable fluoroalkylated vinyl iodides and proved the straightforward transformability of the products in cross-coupling chemistry to obtain conjugated systems.
- Varga, Bálint,Tóth, Balázs L.,Béke, Ferenc,Csenki, János T.,Kotschy, András,Novák, Zoltán
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supporting information
p. 4925 - 4929
(2021/07/01)
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- Asymmetric Hydrosilylation of β-Silyl Styrenes Catalyzed by a Chiral Palladium Complex
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A palladium complex coordinated with a chiral SIPHOS ligand was evaluated as an efficient catalyst for asymmetric hydrosilylation of β-silyl styrenes with trichlorosilane and 23 1,2-bis(silyl) chiral compounds were produced. Good to excellent enantioselec
- He, Yu-Han,Ji, Yang,Li, Rui,Su, Yan,Wang, Yi-Fan
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supporting information
(2022/02/10)
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- BTK Inhibitors and uses thereof
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The invention discloses a bruton's tyrosine kinase (BTK) inhibitor and use thereof. Specifically, the invention provides heteroaromatic compounds or stereoisomers, geometrical isomers, tautomers, racemates, nitrogen oxides, hydrates, solvates, metabolites and pharmaceutically acceptable salts or prodrugs thereof, and pharmaceutical compositions containing the heteroaromatic compounds; the invention also discloses use of the heteroaromatic compounds or the pharmaceutical compositions containing the heteroaromatic compounds in preparation of medicines; the medicines can be used for treating autoimmune diseases, inflammatory diseases or proliferative diseases.
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Paragraph 1839-1844
(2020/05/02)
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- Self-Assembly and Molecular Recognition in Water: Tubular Stacking and Guest-Templated Discrete Assembly of Water-Soluble, Shape-Persistent Macrocycles
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Supramolecular chemistry in aqueous media is an area with great fundamental and practical significance. To examine the role of multiple noncovalent interactions in controlled assembling and binding behavior in water, the self-association of five water-soluble hexakis(m-phenylene ethynylene) (m-PE) macrocycles, along with the molecular recognition behavior of the resultant assemblies, is investigated with UV-vis, fluorescence, CD, and NMR spectroscopy, mass spectrometry, and computational studies. In contrast to their different extents of self-aggregation in organic solvents, all five macrocycles remain aggregated in water at concentrations down to the micromolar (μM) range. CD spectroscopy reveals that 1-F6 and 1-H6, two macrocycles carrying chiral side chains and capable of H-bonded self-association, assemble into tubular stacks. The tubular stacks serve as supramolecular hosts in water, as exemplified by the interaction of macrocycles 1-H6 and 2-H6 and guests G1 through G4, each having a rod-like oligo(p-phenylene ethynylene) (p-PE) segment flanked by two hydrophilic chains. Fluorescence and 1H NMR spectroscopy revealed the formation of kinetically stable, discrete assemblies upon mixing 2-H6 and a guest. The binding stoichiometry, determined with fluorescence, 1H NMR, and ESI-MS, reveals that the discrete assemblies are novel pseudorotaxanes, each containing a pair of identical guest molecules encased by a tubular stack. The two guest molecules define the number of macrocyclic molecules that comprise the host, which curbs the "infinite" stack growth, resulting in a tubular stack with a cylindrical pore tailoring the length of the p-PE segment of the bound guests. Each complex is stabilized by the action of multiple noncovalent forces including aromatic stacking, side-chain H-bonding, and van der Waals interactions. Thus, the interplay of multiple noncovalent forces aligns the molecules of macrocycles 1 and 2 into tubular stacks with cylindrical inner pores that, upon binding rod-like guests, lead to tight, discrete, and well-ordered tubular assemblies that are unprecedented in water.
- Wang, Qiuhua,Zhong, Yulong,Miller, Daniel P.,Lu, Xiaoxing,Tang, Quan,Lu, Zhong-Lin,Zurek, Eva,Liu, Rui,Gong, Bing
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supporting information
p. 2915 - 2924
(2020/02/04)
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- γ-Carboline synthesis enabled by Rh(iii)-catalysed regioselective C-H annulation
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A redox-neutral Rh(iii)-catalyzed C-H annulation of indolyl oximes was developed. Relying on the use of various alkynyl silanes as the terminal alkyne surrogates, the reaction exhibited a reverse regioselectivity, thus giving an exclusive and easy way for the synthesis of a wide range of substituent free γ-carbolines at C3 position with high efficiency. Deuterium-labelling experiments and kinetic analysis have preliminarily shed light on the working mode of this catalytic system. This journal is
- Jiang, Bo,Jia, Jingwen,Sun, Yufei,Wang, Yichun,Zeng, Jing,Bu, Xiubin,Shi, Liangliang,Sun, Xiaoying,Yang, Xiaobo
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supporting information
p. 13389 - 13392
(2020/11/10)
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- Dibenzochrysene derivative compounds and organic light-emitting diode including the same
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PURPOSE: A dibenzochrysene derivative compound is provided to have excellent driving voltage, current efficiency, etc, thereby capable of improving driving voltage of a device and luminous efficiency. CONSTITUTION: A dibenzochrysene derivative compound is represented by chemical formula 1. An organic electroluminescence device comprises an anode, a cathode, and the dibenzochrysene derivative compound between the anode and the cathode. The dibenzochrysene derivative compound is comprised in a light-emitting layer between the anode and the cathode. One or more layer consisting of a hole injection layer, a hole transport layer, an electron block layer, a hole block layer, an electron transport layer, an electron injection layer is comprised between the anode and the cathode.
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Paragraph 0317-0323
(2019/07/25)
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- Visible-Light-Photosensitized Aryl and Alkyl Decarboxylative Functionalization Reactions
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Despite significant progress in aliphatic decarboxylation, an efficient and general protocol for radical aromatic decarboxylation has lagged far behind. Herein, we describe a general strategy for rapid access to both aryl and alkyl radicals by photosensitized decarboxylation of the corresponding carboxylic acids esters followed by their successive use in divergent carbon–heteroatom and carbon–carbon bond-forming reactions. Identification of a suitable activator for carboxylic acids is the key to bypass a competing single-electron-transfer mechanism and “switch on” an energy-transfer-mediated homolysis of unsymmetrical σ-bonds for a concerted fragmentation/decarboxylation process.
- Patra, Tuhin,Mukherjee, Satobhisha,Ma, Jiajia,Strieth-Kalthoff, Felix,Glorius, Frank
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supporting information
p. 10514 - 10520
(2019/07/12)
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- In Situ Generation of Alkynylzinc and Its Subsequent Negishi Reaction in a Flow Reactor
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A highly efficient and convenient Negishi cross-coupling reaction has been developed for the synthesis of unsymmetrical alkynes and enynes in a continuous-flow process. The reaction proceeds through an in situ generated alkynylzinc reagent by the reaction of lithium acetylide with zinc halide at room temperature followed by a cross-coupling reaction with aryl or vinyl iodides. The notable features of this work compared to the conventional benchtop method are mild reaction conditions, good to excellent yields, broad functional-group compatibility, short residence time (73 sec) and especially desilylation of TMS group with the residence time of only 10.5 sec.
- Kandasamy, Mohanraj,Huang, Yu- Hsuan,Ganesan, Balaji,Senadi, Gopal Chandru,Lin, Wei-Yu
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p. 4349 - 4356
(2019/07/03)
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- Directional Self-Sorting with Cucurbit[8]uril Controlled by Allosteric π–π and Metal–Metal Interactions
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To maximize Coulombic interactions, cucurbit[8]uril (CB[8]) typically forms ternary complexes that distribute the positive charges of the pair of guests (if any) over both carbonylated portals of the macrocycle. We present here the first exception to this recognition pattern. Platinum(II) acetylides flanked by 4′-substituted terpyridyl ligands (tpy) form 2:1 complexes with CB[8] in an exclusively stacked head-to-head orientation in a water/acetonitrile mixture. The host encapsulates the pair of tpy substituents, and both positive Pt centers sit on top of each other at the same CB[8] rim, leaving the other rim free of any interaction with the guests. This dramatic charge imbalance between the CB[8] rims would be electrostatically penalizing, were it not for allosteric π–π interactions between the stacked tpy ligands, and possible metal-metal interactions between both Pt centers. When both tpy and acetylides are substituted with aryl units, the metal-ligand complexes form 2:2 assemblies with CB[8] in aqueous medium, and the directionality of the assembly (head-to-head or head-to-tail) can be controlled, both kinetically and thermodynamically.
- Kotturi, Kondalarao,Masson, Eric
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supporting information
p. 8670 - 8678
(2018/06/26)
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- COMPOUND FOR ORGANIC OPTOELECTRONIC DEVICE, ORGANIC OPTOELECTRONIC DEVICE AND DISPLAY APPARATUS
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The present invention relates to a compound for an organic optoelectronic device represented by chemical formula 1, an organic optoelectronic device employing the same and a display device apparatus. The details of chemical formula 1 are as defined in the specification.
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Paragraph 0183; 0184
(2018/12/11)
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- Fabrication of Neutral Supramolecular Polymeric Films via Post-electropolymerization of Discrete Metallacycles
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Self-assembly post-modification has proven to be an efficient strategy to build higher-order supramolecular architectures and functional materials. In this study, we successfully realized the construction of a new family of neutral supramolecular polymeric films containing well-defined metallacycles as the main scaffolds through combination of coordination-driven self-assembly with post-electropolymerization. The obtained neutral polymeric materials were fully characterized by the cyclic voltammogram (CV), SEM, and TEM. The thickness of the films was able to be well regulated by the number of scanning cycles. Moreover, we found that the shape of the metallacycles and the number of triphenylamine moieties played important roles in the formation of the final polymer films. We believe that the introduction of the neutral metallacycles into the final polymer structures not only enriches the library of supramolecular polymeric films but also provides a new platform to study neutral molecule detection, separation, and capture.
- Yin, Guangqiang,Chen, Lijun,Wang, Cuihong,Yang, Haibo
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supporting information
p. 134 - 138
(2017/12/26)
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- Synthesis of α-fluoroimines by copper-catalyzed reaction of diarylacetylenes and n-fluorobenzenesulfonimide
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Difunctionalization of unsaturated bonds with fluorinating reagents has been regarded as an efficient route to vicdifunctional organic fluorides. Here we report a coppercatalyzed synthesis of α-fluoroimines from diarylacetylenes and N-fluorobenzenesulfonimide. Mechanistically, the reaction initiates from the generation of imidyl radical, which reacts with alkyne to give the product. The resulting α-fluoroimine can easily be transformed into other organic fluorides such as fluoroketone and fluoroamines.
- Yip, Shu Jan,Yoshidomi, Tetsushi,Murakami, Kei,Itami, Kenichiro
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supporting information
p. 329 - 331
(2018/03/01)
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- Au-Catalyzed Intermolecular [2+2] Cycloadditions between Chloroalkynes and Unactivated Alkenes
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The [2+2] cycloaddition is a versatile strategy for the synthesis of strained cyclobutenes of high synthetic value. In this study, two efficient intermolecular [2+2] cycloadditions between two different types of chloroalkynes and unactivated alkene are realized with gold catalysis. Of significance is that the reaction works with challenging monosubstituted unactivated alkenes, which is unprecedented in gold catalysis and scarcely documented in other metal-catalyzed/promoted reactions; moreover, the reaction exhibits excellent regioselectivities, which are much better than those reported in literature. With 1,2-disubstituted unactivated alkenes, the reaction is largely stereospecific. The cyclobutene products can be prepared in nearly gram scale and readily undergo further reactions including various cross-coupling reactions using the C(sp2)-Cl and/or C(sp2)-SPh bond, which in turn substantially broaden the scope of accessible cyclobutenes and enhance the synthetic utility of this bimolecular reaction.
- Bai, Yu-Bin,Luo, Zaigang,Wang, Yuguang,Gao, Jin-Ming,Zhang, Liming
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supporting information
p. 5860 - 5865
(2018/05/14)
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- Trimethylsilyl-Protected Alkynes as Selective Cross-Coupling Partners in Titanium-Catalyzed [2+2+1] Pyrrole Synthesis
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Trimethylsilyl (TMS)-protected alkynes served as selective alkyne cross-coupling partners in titanium-catalyzed [2+2+1] pyrrole synthesis. Reactions of TMS-protected alkynes with internal alkynes and azobenzene under the catalysis of titanium imido comple
- Chiu, Hsin-Chun,Tonks, Ian A.
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supporting information
p. 6090 - 6094
(2018/05/30)
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- Discovery of a novel series of N-hydroxypyridone derivatives protecting astrocytes against hydrogen peroxide-induced toxicity via improved mitochondrial functionality
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Astrocytes play a key role in brain homeostasis, protecting neurons against neurotoxic stimuli such as oxidative stress. Therefore, the neuroprotective therapeutics that enhance astrocytic functionality has been regarded as a promising strategy to reduce brain damage. We previously reported that ciclopirox, a well-known antifungal N-hydroxypyridone compound, protects astrocytes from oxidative stress by enhancing mitochondrial function. Using the N-hydroxypyridone scaffold, we have synthesized a series of cytoprotective derivatives. Mitochondrial activity assay showed that N-hydroxypyridone derivatives with biphenyl group have comparable to better protective effects than ciclopirox in astrocytes exposed to H2O2. N-hydroxypyridone derivatives, especially 11g, inhibited H2O2-induced deterioration of mitochondrial membrane potential and oxygen consumption rate, and significantly improved cell viability of astrocytes. The results indicate that the N-hydroxypyridone motif can provide a novel cytoprotective scaffold for astrocytes via enhancing mitochondrial functionality.
- Singh, Sarbjit,Goo, Ja-Il,Noh, Hyojin,Lee, Sung Jae,Kim, Myoung Woo,Park, Hyejun,Jalani, Hitesh B.,Lee, Kyeong,Kim, Chunsook,Kim, Won-Ki,Ju, Chung,Choi, Yongseok
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supporting information
p. 1394 - 1405
(2017/02/18)
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- Two- and three-dimensional silver acetylide frameworks with high-nuclearity silver cluster building blocks assembled using a bifunctional (4-ethynylphenyl)diphenyl phosphine ligand
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A bifunctional ligand precursor (4-ethynylphenyl)diphenyl phosphine was synthesized and used for constructing silver acetylide frameworks. Its reaction with Ag(I) in the presence of triethylamine afforded silver acetylide [AgL]n, in which L = Ph2P-C6H4-4-C[tbnd]C?could act as a bifunctional ligand bearing both phenylethynide and phosphine binding sites for Ag(I). Reactions of [AgL]nand AgCF3CO2under different conditions gave four silver acetylides. They are [Ag18L8(CF3COO)6(HCO3)4(DMF)4]n(1, DMF = dimethylformamide), [Ag20L8(CF3COO)12(DMF)6]n(2), [Ag17L6(CF3COO)9(HCO3)2]n(3), and [Ag17L6(CF3COO)9.58(HCO3)1.42]n(4). Crystallographic studies revealed that complex 1 crystallized in the triclinic space group P1ˉ with a = 14.1252(9) ?, b = 18.6012(12) ?, c = 25.2137(17) ?, α = 108.340(2)°, β = 95.386(2)°, γ = 95.535(2)°, V = 6204.6(7) ?3, and Z = 1. Complex 2 crystallized in the monoclinic space group C2/c with a = 48.046(4) ?, b = 14.1860(10) ?, c = 34.943(2) ?, β = 98.315(3)°, V = 23,566(3) ?3, and Z = 4. Complex 3 crystallized in the triclinic space group P1ˉ with a = 15.5690(7) ?, b = 16.7707(8) ?, c = 34.0810(16) ?, α = 93.4040(10)°, β = 100.3690(10)°, γ = 94.8250(10)°, V = 8697.1(7) ?3, and Z = 2. Complex 4 crystallized in the triclinic space group P1ˉ with a = 15.5396(6) ?, b = 16.7595(7) ?, c = 34.0225(15) ?, α = 93.8140(10)°, β = 100.1000(10)°, γ = 94.9770(10)°, V = 8660.2(6) ?3, and Z = 2. The presence of Ag(I)–ethynide, Ag(I)–P and Ag(I)–Ag(I) bonding interactions makes all four silver acetylides to have two- and three-dimensional framework structures with unusual high-nuclearity silver cluster building blocks.
- Zhang, Shaokang,Zhang, Zongyao,Cao, Rui
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- Enantioselective synthesis of β-fluoro-β-aryl-α-aminopentenamides by organocatalytic [2,3]-sigmatropic rearrangement
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The tetramisole-promoted catalytic enantioselective [2,3]-sigmatropic rearrangement of quaternary ammonium salts bearing a (Z)-3-fluoro-3-arylprop-2-ene group generates, after addition of benzylamine, a range of β-fluoro-β-aryl-α-aminopentenamides containing a stereogenic tertiary fluorine substituent. Cyclic and acyclic nitrogen substituents as well as various aromatic substituents are tolerated, giving the β-fluoro-β-aryl-α-aminopentenamide products in up to 76% yield, 96:4 dr, and 98:2 er.
- Kasten, Kevin,Slawin, Alexandra M. Z.,Smith, Andrew D.
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supporting information
p. 5182 - 5185
(2017/11/06)
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- Alkynyl Moiety for Triggering 1,2-Metallate Shifts: Enantiospecific sp2–sp3 Coupling of Boronic Esters with p-Arylacetylenes
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The enantiospecific coupling of secondary and tertiary boronic esters to aromatics has been investigated. Using p-lithiated phenylacetylenes and a range of boronic esters coupling has been achieved by the addition of N-bromosuccinimide (NBS). The alkyne functionality of the intermediate boronate complex reacts with NBS triggering the 1,2-migration of the group on boron to carbon giving a dearomatized bromoallene intermediate. At this point elimination and rearomatization occurs with neopentyl boronic esters, giving the coupled products. However, using pinacol boronic esters, the boron moiety migrates to the adjacent carbon resulting in formation of ortho boron-incorporated coupled products. The synthetic utility of the boron incorporated product has been demonstrated by orthogonal transformation of both the alkyne and boronic ester functionalities.
- Ganesh, Venkataraman,Odachowski, Marcin,Aggarwal, Varinder K.
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supporting information
p. 9752 - 9756
(2017/08/08)
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- A phosphine-free, atom-efficient cross-coupling of aryl iodides with triarylindiums or trialkynylindiums catalyzed by immobilization of palladium(0) in MCM-41
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The first phosphine-free heterogeneous atom-efficient cross-coupling reaction of aryl iodides with triarylindiums or trialkynylindiums was achieved in THF at 68 °C by using 1 mol% of MCM-41-immobilized palladium(0)-Schiff base complex [MCM-41-N,N-Pd(0)] as catalyst, yielding a variety of unsymmetrical biaryls and arylalkynes in good to excellent yields. The heterogeneous palladium(0) catalyst could easily be prepared via a simple procedure from commercially readily available reagents, and recovered by filtration of the reaction solution and recycled at least 10 times without significant loss of activity.
- Lei, Zhiwei,Liu, Haiyi,Cai, Mingzhong
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- COMPOUNDS HAVING NEGATIVE OPTICAL DISPERSION, NEGATIVE OPTICAL DISPERSION COMPOSITION COMPRISING THE COMPOUNDS, AND OPTICALLY ANISOTROPIC BODY COMPRISING THE COMPOSITION
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The present invention relates to a reverse dispersive compound, a reverse dispersive composition and an optical anisotropic body comprising the same. The reverse dispersive compound of the present invention is represented by chemical formula 1, and has improved orientation, thereby enabling to provide an optical anisotropic body having excellent optical properties.COPYRIGHT KIPO 2016
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Paragraph 0119; 0120
(2017/05/17)
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- Synthesis and characterization of arylacetylene derivative as solution processable organic semiconductors for organic thin-film transistors
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New arylacetylene derivative (4,7-bis((4-(thiophen-2-yl)phenyl)ethynyl)benzo[c][1,2,5]thiadiazole; 5) functionalized with thiophene and benzothiadiazole was synthesized and characterized as organic semiconductors for organic thin-film transistors (OTFTs). Compound 5 exhibited p-channel characteristics with carrier mobility as high as 10-4 cm2/Vs and a current on/off ratio >105 for top-contact/bottom-gate OTFT devices.
- Kim, Hyekyoung,Reddy, M. Rajeshkumar,Kwon, Guhyun,Choi, Donghee,Kim, Choongik,Seo, SungYong
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p. 10331 - 10336
(2016/10/18)
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- Nucleophile promoted gold redox catalysis with diazonium salts: C-Br, C-S and C-P bond formation through catalytic Sandmeyer coupling
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Gold-catalyzed C-heteroatom (C-X) coupling reactions are evaluated without using sacrificial oxidants. Vital to the success of this methodology is the nucleophile-assisted activation of aryldiazonium salts, which could be an effective oxidant for converting Au(i) to Au(iii) even without the addition of an assisting ligand or photocatalyst. By accelerating the reaction kinetics to outcompete C-C homo-coupling or diazonium dediazoniation, gold-catalyzed Sandmeyer reactions were achieved with different nucleophiles, forming C-Br, C-S and C-P bonds in high yields and selectivities.
- Peng, Haihui,Cai, Rong,Xu, Chang,Chen, Hao,Shi, Xiaodong
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p. 6190 - 6196
(2016/09/03)
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- Fluoroform-Derived CuCF3 for Trifluoromethylation of Terminal and TMS-Protected Alkynes
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An efficient trifluoromethylation reaction of alkynes using a fluoroform-derived CuCF3 reagent is described. The CF3 source is the inexpensive industrial waste fluoroform (CF3H). The air-stable CuCF3 reagent can be prepared in large quantities and is convenient to use. Synthetically useful trifluoromethylated alkynes containing a wide range of functional groups were successfully synthesized under mild conditions. Both terminal and TMS-protected alkynes gave the products in one step. The beneficial effect of a diamine ligand tetramethylethylenediamine (TMEDA) with the fluoroform-derived CuCF3 reagent was also demonstrated.
- He, Lisi,Tsui, Gavin Chit
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supporting information
p. 2800 - 2803
(2016/07/06)
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- Cleavage of the Carbon–Carbon Triple Bonds of Arylacetylenes for the Synthesis of Arylnitriles without a Metal Catalyst
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Cleavage of the carbon–carbon triple bonds of alkynes was achieved, which led to the synthesis of arylnitriles under transition-metal-free conditions. A vast range of terminal alkyne substrates underwent this reaction to provide the corresponding nitriles in moderate to good yields with good functional group tolerance.
- Lin, Yuanguang,Song, Qiuling
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supporting information
p. 3056 - 3059
(2016/07/12)
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- Charge transfer emission in oligotriarylamine-triarylborane compounds
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Donor-acceptor compounds exhibiting charge transfer emission are of interest in a variety of different contexts, for example, for nonlinear optical processes and for sensor applications. Recently investigated triarylamine-triarylborane compounds represent an important class of donor-acceptor systems, and we explored to what extent their charge-transfer properties can be further improved by using stronger amine donors and borane acceptors than prior studies. The oligotriarylamine employed here is a much stronger donor than previously used triarylamines containing single nitrogen centers. In order to increase the acceptor strength, the electron-accepting unit was equipped with two (instead of one) dimesitylboron substituents. In our comparative study, six donor-acceptor compounds were synthesized and investigated by cyclic voltammetry and optical spectroscopy. An increase of the donor strength through replacement of an ordinary triarylamine by an oligotriarylamine unit leads to the expected energetic stabilization of charge transfer (CT) excited states, but the emission solvatochromism is not more pronounced. The attempted increase of the acceptor strength by substitution of the acceptor moiety by two (instead of one) dimesitylboron groups leads to a drastic decrease of emission quantum yields. On the basis of these results, our purely experimental study provides fundamental guidelines for the design of new triarylamine-triarylborane donor-acceptor compounds with favorable charge-transfer emission properties.
- Bonn, Annabell G.,Wenger, Oliver S.
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p. 4097 - 4107
(2015/05/05)
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- Reverse engineering of conjugated microporous polymers: Defect structures of tetrakis(4-ethynylphenyl)stannane networks
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Two different conjugated microporous polymers (CMPs) based on tetrakis(4-ethynylphenyl)stannane as the repeating unit were synthesized and their BET surfaces and thermal properties were investigated. The first direct method to elucidate the molecular structure of the organic linkers between the tin centers by digestion of the CMP is described. Selective cleavage of the tin-carbon bonds with chloroacetic acid afforded the isolated bridging units and provided insight into the surprisingly varied chemical composition of these networks. Burn your bridges: Two different conjugated microporous polymers (CMPs) based on tetrakis(4-ethynylphenyl)stannane as the repeating unit were synthesized and characterized. Selective cleavage of the tin-carbon bonds with chloroacetic acid affords the isolated bridging units, thereby providing insight into the structure of the organic linkers and the surprisingly varied chemical composition of these networks.
- Uptmoor, Andrea C.,Freudenberg, Jan,Schw?bel, S. Thimon,Paulus, Fabian,Rominger, Frank,Hinkel, Felix,Bunz, Uwe H. F.
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supporting information
p. 14673 - 14676
(2016/02/09)
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- HETEROCYCLIC MODULATORS OF LIPID SYNTHESIS AND COMBINATIONS THEREOF
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Heterocyclic modulators of lipid synthesis are provided as well as pharmaceutically acceptable salts thereof; pharmaceutical compositions comprising such compounds; and methods of treating conditions characterized by disregulation of a fatty acid synthase pathway by the administration of such compounds and combinations of such compounds and other therapeutic agents.
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Page/Page column 159
(2015/07/07)
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- Rh(III)-catalyzed cyclization reaction of azoles with alkynes: Efficient synthesis of azole-fused-pyridines
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A Rh(III)-catalyzed cyclization of azoles with alkynes has been developed. A variety of azole-fused-pyridines were obtained in good to excellent yields and regioselectivity. Both the C5 and the C4 position of azoles were suitable for the reaction.
- Chen, Xuebing,Wu, Youzhi,Xu, Jinyi,Yao, Hequan,Lin, Aijun,Huang, Yue
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supporting information
p. 9186 - 9189
(2015/09/07)
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- Combined spectroscopic and quantum chemical study of [trans-Ru(C≡CC6H4R1-4)2(dppe)2]n+ and [trans-Ru(C≡CC6H4R1-4)(C≡CC6H4R2-4)(dppe)2]n+ (n = 0, 1) complexes: Interpretations beyond the lowest energy conformer paradigm
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The reaction of trans-RuCl(C≡CC6H4R1-4)(dppe)2 (2: R1 = Me (a), C5H11 (b), OMe (c), CO2Me (d), NO2 (e), C≡CSiMe3 (f), C≡CBut (g), NH2 (h)), prepared in situ from reactions of [RuCl(dppe)2]OTf ([1]OTf) with terminal alkynes in CH2Cl2 solutions containing 1,8-diazabicycloundec-7-ene (DBU) and TlBF4, provides a convenient and rapid route to bis(acetylide) complexes trans-Ru(C≡CC6H4R1-4)2(dppe)2 (3a-h) and trans-Ru(C≡ CC6H4R1-4)(C≡CC6H4R2-4)(dppe)2 (4, R1 = C≡CSiMe3, R2 = NH2; 5, R1 = CO2Me, R2 = NH2; 6, R1 = CO2Me, R2 = OMe). However, even in the absence of the chloride abstracting reagent, more strongly electron donating substituents (e.g., R1 = OMe (2c), NH2 (2h)) promote sufficient ionization of the Ru-Cl bond in trans-RuCl(C≡CC6H4R -4)(dppe)2 to lead to slow conversion to bis(alkynyl) complexes 3c,h in the presence of excess alkyne and DBU. Desilylation of 2f and 3f affords 2i and 3i (R1 = C≡CH), respectively. The molecular structures of 3a-d,f-i have been determined and are reported together with the structures of the monoalkynyl complexes 2f,g,i and compared with related compounds from the literature. Complexes 3a-i and 4-6 undergo one reversible electrochemical oxidation process, which can be attributed to depopulation of an orbital with significant alkynyl ligand character. The one-electron-oxidation products [3f]?+, [3h]?+, [4]?+, and [5]?+, chosen to serve as representative examples of this family of complexes, each exhibit a series of NIR absorptions between 15000 and 5000 cm-1 which on the basis of TDDFT calculations cannot be attributed to a single, static lowest energy molecular structure. Rather, the transitions that are responsible for the absorption band envelope have varying degrees of LMCT and inter-alkynyl ligand IVCT or MLCT character that depend not only on the nature of the Rn groups but also on the ensemble of thermally populated molecular conformers in solution with various relative orientations of the metal fragment and arylethynyl moieties. (Figure Presented)
- Marqués-González, Santiago,Parthey, Matthias,Yufit, Dmitry S.,Howard, Judith A.K.,Kaupp, Martin,Low, Paul J.
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supporting information
p. 4947 - 4963
(2015/04/27)
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- Autotandem catalysis: Synthesis of pyrroles by gold-catalyzed cascade reaction
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A novel synthesis of substituted pyrroles by a gold(I)-catalyzed cascade reaction has been developed. The reaction proceeded with an autotandem catalysis consisting of an initial addition of gold-acetylide to an acetal moiety and was followed by gold-catalyzed 5-endo-dig cyclization and aromatization. Gold catalysts play a dual role in activating nucleophilicity or electrophilicity of terminal acetylenes by forming gold-acetylides or by π-coordination. The formal (3 + 2) annulation of two components provided a variety of substituted pyrroles in a modular fashion.
- Ueda, Hirofumi,Yamaguchi, Minami,Kameya, Hiroshi,Sugimoto, Kenji,Tokuyama, Hidetoshi
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supporting information
p. 4948 - 4951
(2015/04/27)
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- Self-assembly and (hydro)gelation triggered by cooperative π-π And unconventional C-H×××X hydrogen bonding interactions
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Weak C-H×××X hydrogen bonds are important stabilizing forces in crystal engineering and anion recognition in solution. In contrast, their quantitative influence on the stabilization of supramolecular polymers or gels has thus far remained unexplored. Herein, we report an oligophenyleneethynylene (OPE)-based amphiphilic PtII complex that forms supramolecular polymeric structures in aqueous and polar media driven by π-π and different weak C-H×××X (X=Cl, O) interactions involving chlorine atoms attached to the PtII centers as well as oxygen atoms and polarized methylene groups belonging to the peripheral glycol chains. A collection of experimental techniques (UV/Vis, 1D and 2D NMR, DLS, AFM, SEM, and X-Ray diffraction) demonstrate that the interplay between different weak noncovalent interactions leads to the cooperative formation of self-assembled structures of high aspect ratio and gels in which the molecular arrangement is maintained in the crystalline state. Growing hand in hand! Multiple unconventional C-H×××X (X=O, Cl) hydrogen-bonding interactions, assisted by π-π interactions, are strong enough to drive the cooperative formation of supramolecular polymers and gels in polar and aqueous media. The aggregates consolidate themselves in the crystals, as shown by combined studies in solution and crystalline state. Copyright
- Rest, Christina,Mayoral, María José,Fucke, Katharina,Schellheimer, Jennifer,Stepanenko, Vladimir,Fernández, Gustavo
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supporting information
p. 700 - 705
(2014/01/23)
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- New hole transporting materials based on hexaarylbenzene and aromatic amine moiety for organic light-emitting diodes
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Three different new hole transport compounds, namely DPAP-TB, 1-PNAP-TB and 2-PNAP-TB, were synthesized by Sonogashira coupling and Diels-Alder reaction. Synthesized materials exhibited high Tgin the range of 118 to 133 °C. These values are higher than that of NPB, which is commonly used as a hole transporting material. OLED devices were fabricated by the synthesized compounds using the solution process as a hole transporting layer. Device structure was ITO/PEDOT:PSS (40 nm)/synthesized compounds or NPB (20 nm)/Alq3 (70 nm)/LiF/Al. Luminance efficiencies and external quantum efficiencies of DPAP-TB, 1-PNAP-TB and 2-PNAP-TB devices were 3.98, 4.62, 4.22 cd/A, and 1.35, 1.56, 1.43% at 20 mA/cm2, respectively. In luminance efficiency and external quantum efficiency, 1-PNAP-TB especially had superior property to NPB. Copyright
- Kim, Seungho,Lee, Sang-Ho,Shin, Hwangyu,Kay, Kwang-Yol,Park, Jongwook
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p. 6382 - 6385
(2014/11/07)
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- HETEROCYCLIC MODULATORS OF LIPID SYNTHESIS
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Heterocyclic modulators of lipid synthesis are provided as well as pharmaceutically acceptable salts thereof; pharmaceutical compositions comprising such compounds; and methods of treating conditions characterized by disregulation of a fatty acid synthase pathway by the administration of such compounds.
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Page/Page column 144
(2014/01/18)
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- H-aggregates of oligophenyleneethynylene (OPE)-BODIPY systems in water: Guest size-dependent encapsulation mechanism and co-aggregate morphology
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The synthesis of a new oligophenyleneethynylene (OPE)-4,4-difluoro-4-bora- 3a,4a-diaza-s-indacene (BODIPY) bolaamphiphile 1 and its aqueous self-assembly are reported. Compound 1 forms H-type aggregates in aqueous and polar media, as demonstrated by UV/Vis and fluorescence experiments. Concentration-dependent 1H NMR studies in CD3CN reveal that the BODIPY units are arranged on top of each other into π-stacks with H-type excitonic coupling, as supported by ROESY NMR and theoretical calculations and visualized by Cryo-SEM studies. A detailed analysis of the spectral changes observed in temperature-dependent UV/Vis studies reveals that 1 self-assembles in a non-cooperative (isodesmic) fashion in water. The hydrophobic interior of these self-assembled structures can be exploited to encapsulate hydrophobic dyes, such as tetracene and anthracene. Both dyes absorb in a complementary region of the UV/Vis spectrum and are small enough to interact with the hydrophobic segments of 1. Temperature-dependent UV/Vis studies reveal that the spectral changes associated to the encapsulation mechanism of tetracene can be fitted to a Boltzmann function, and the initially flexible fibres of 1 rigidify upon guest addition. In contrast, the co-assembly of 1 and anthracene is a highly cooperative process, which suggests that a different class of (more-ordered) aggregates is formed. TEM and Cryo SEM imaging show the formation of uniform spherical nanoparticles, indicating that a subtle change in the guest molecular structure induces a significant change in the encapsulation mechanism and, consequently, the aggregate morphology. Dye encapsulation: We report the aqueous self-assembly of a new oligophenyleneethynylene (OPE)-BODIPY amphiphilic derivative into H-type aggregates and its ability to encapsulate hydrophobic guest molecules. Subtle changes in the guest size induce a dramatic change of the encapsulation mechanism. Addition of tetracene leads to the non-cooperative formation of stiff fibres, whereas co-assembly with anthracene is a highly cooperative process, leading to highly organized micellar assemblies.
- Allampally, Naveen Kumar,Florian, Alexander,Mayoral, Maria Jose,Rest, Christina,Stepanenko, Vladimir,Fernandez, Gustavo
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supporting information
p. 10669 - 10678
(2014/11/07)
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- 2-(1,2,3-Triazol-4-yl)pyridine-containing ethynylarenes as selective 'turn-on' fluorescent chemosensors for Ni(II)
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A series of ethynylarene compounds containing 2-(1,2,3-triazol-4-yl)pyridine chelating units were studied as fluorescent chemosensors for metal cations in aqueous solution. Analogs possessing two chelating units bridged by either 1,4-diethynylphenyl or 2,7-diethynylnaphthyl subunits displayed large hypsochromic shifts coupled with signal intensification when exposed to increasing concentrations of Ni(II), a unique response among 22 metal cation analytes. This response was shown to be reversible, and is proposed to derive from disruption of aggregate formation upon Ni(II) binding at the peripheral chelating units.
- Christensen, Joseph A.,Fletcher, James T.
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supporting information
p. 4612 - 4615
(2014/12/10)
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- Electrochemical control of a non-covalent binding between ferrocene and beta-cyclodextrin
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The forces required for the detachment of ferrocene (Fc) from β-cyclodextrin (βCD) in a single host (βCD)-guest (Fc) complex were investigated using force spectroscopy under electrochemical conditions. The redox state of the guest Fc moiety as well as the structure of the supporting matrix was found to decisively affect the nanomechanical properties of the complex. This journal is
- Kolivo?ka,Mohos,Pobelov,Rohrbach,Yoshida,Hong,Fu,Moreno-García,Mészáros,Broekmann,Hromadová,Sokolová,Valá?ek,Wandlowski, Th.
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supporting information
p. 11757 - 11759
(2015/05/20)
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- NHC catalysed trimethylsilylation of terminal alkynes and indoles with Ruppert's reagent under solvent free conditions
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An organo-catalytic protocol for the trimethylsilylation of terminal alkynes employing Ruppert's reagent (CF3SiMe3) as a trimethylsilyl source has been developed under solvent and fluoride free conditions. This method was found to be very effective as a variety of terminal alkynes bearing aliphatic or aromatic substituents underwent smooth transformation to their corresponding silylated products in excellent yields within a few minutes using N-heterocyclic carbene as an organo-catalyst. This methodology was also applied to the chemospecific N-silylation of indoles. This journal is
- Arde, Panjab,Reddy, Virsinha,Anand, Ramasamy Vijaya
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p. 49775 - 49779
(2014/12/11)
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- Organoborane-containing polyacetylene derivatives: Synthesis, characterization, and fluoride-sensing properties
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Triarylborane-containing polyacetylene derivatives (2a-c) were synthesized by the polymerization of the corresponding monomers with Rh+(nbd)[C6H5B-(C6H5)3] catalyst. The anion se
- Hu, Yanming,Zhao, Zhongfu,Bai, Xue,Yuan, Xuecheng,Zhang, Xuequan,Masuda, Toshio
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p. 55179 - 55186
(2015/02/18)
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- Aerobic oxynitration of alkynes with tBuONO and TEMPO
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An efficient method for stereoselective nitroaminoxylation of alkyne has been reported. The reaction enjoys a broad substrate scope, good functional group tolerance, and high yields. Synthetically useful α-nitroketones can be accessed through these products in a single step.
- Dutta, Uttam,Maity, Soham,Kancherla, Rajesh,Maiti, Debabrata
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supporting information
p. 6302 - 6305
(2015/02/19)
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- Simplifying the conductance profiles of molecular junctions: The use of the trimethylsilylethynyl moiety as a molecule-gold contact
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Conductance across a metal|molecule|metal junction is strongly influenced by the molecule-substrate contacts, and for a given molecular structure, multiple conductance values are frequently observed and ascribed to distinct binding modes of the contact at each of the molecular termini. Conjugated molecules containing a trimethylsilylethynyl terminus, -C≡CSiMe 3 give exclusively a single conductance value in I(s) measurements on gold substrates, the value of which is similar to that observed for the same molecular backbone with thiol and amine based contacting groups when bound to under-coordinated surface sites.
- Marques-Gonzalez, Santiago,Yufit, Dmitry S.,Howard, Judith A.K.,Martin, Santiago,Osorio, Henrry M.,Garcia-Suarez, Victor M.,Nichols, Richard J.,Higgins, Simon J.,Cea, Pilar,Low, Paul J.
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supporting information
p. 338 - 341
(2013/03/14)
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- Phenoxide-mediated Sonogashira coupling of trimethylsilylalkynes and aryliodides: Practical synthesis of phenolic-hydroxy-substituted diarylethynes and 1,4-diarylbutadiynes
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We successfully synthesized phenolic-hydroxy-substituted diarylethynes and 1,4-diarylbutadiynes from trimethylsilylalkynes and aryliodides via silyl-group-migration-induced deprotection of alkynes and the usual Sonogashira coupling. The phenol moiety, which works as a desilylating agent, can be attached to any position in the coupling partner. This improvement for Sonogashira coupling would be highly effective, especially when the coupling partner has a phenol moiety. Additionally, the stability of the migrated silyl moiety on the ethynylation of 2-iodophenol is discussed.
- Shigeta, Masayuki,Watanabe, Junji,Konishi, Gen-Ichi
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supporting information
p. 1761 - 1764
(2013/04/10)
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