- C(sp3)-H Monoarylation of Methanol Enabled by a Bidentate Auxiliary
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With the assistance of a practical directing group (COAQ), the first catalytic protocol for the palladium-catalyzed C(sp3)-H monoarylation of methanol has been developed, offering an invaluable synthesis means to establish extensive derivatives of crucial arylmethanol functional fragments. Furthermore, the gram-scale reaction, broad substrate scope, excellent functional group compatibility, and even the practical synthesis of medicines further demonstrate the usefulness of this strategy.
- Gou, Quan,Ran, Man,Ren, Jian,Tan, Xiaoping,Yuan, Binfang,Yuan, Tengrui,Zhang, Ming-Zhong,Zhang, Xing
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supporting information
p. 118 - 123
(2021/01/13)
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- Synthesis, mesomorphic properties and nonlinear optical studies of alkyl and alkoxy phenylacetylene containing phenazine fused extended triphenylene discotic liquid crystalline dyes
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Herein, we have reported the alkyl and alkoxy phenylacetylene containing phenazine fused triphenylene discotic liquid crystals (DLCs) which are obtained by the condensation reaction of triphenylene-1,2-diquinone with 1,2-diamino-4,5-dibromobenzene, followed by Sonogashira C–C coupling reaction with 4-alkyl-phenylacetylene or 4-alkoxy-phenylacetylene. Six novel derivatives were synthesized and evaluated for their thermal and optical properties. They show a broad range of hexagonal columnar phase and retain their mesophase up to room temperature upon cooling from the isotropic liquid. Thermotropic liquid crystalline properties of all the compounds were studied by polarised optical microscopy (POM), differential scanning calorimetry (DSC). The self-assembly of mesophase structure was investigated by X-ray diffraction (XRD) studies. Thermogravimetric analysis of all the mesogens shows good thermal stability over a broad temperature range. The photophysical properties of newly synthesized compounds were measured using UV–Vis absorption and photoluminescence emission spectroscopy in anhydrous chloroform solvent. The π-extended conjugation in these mesogens exhibit strong absorption bands falling around 270–487 nm and corresponding emission band at 657–663 nm respectively. The high delocalization of π– electrons in extended discotic mesogens show high nonlinear optical properties when measured under excitation by nanosecond laser pulses at 532 nm. These materials may find distinctive applications in the semiconducting devices.
- Gowda, Ashwathanarayana,Jacob, Litwin,Patra, Alakananda,George, Agnes,Philip, Reji,Kumar, Sandeep
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p. 128 - 135
(2018/08/07)
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- Organic hole transport material and preparation method and application thereof
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The invention provides an organic hole transport material and a preparation method and application thereof. The structural general formula of the organic hole transport material is shown in the specification, and in the formula, R is ethyl, propyl, isopropyl or butyl. The preparation method is simple and easy to implement, the structure is definite, and the prepared organic hole transport materialhas high photoelectric conversion efficiency and can be applied to perovskite solar cells.
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Paragraph 0057-0059
(2019/07/01)
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- Enhanced electro-optic activity from the triarylaminophenyl-based chromophores by introducing heteroatoms to the donor
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A series of chromophores T1-T3 based on the same thiophene π-conjugation and tricyanofuran acceptor (TCF) but with different heteroatoms in the triarylaminophenyl (TAA) donors have been synthesized and systematically investigated in this study. Density functional theory (DFT) was used to calculate the HOMO-LUMO energy gaps and first-order hyperpolarizability (β) of these chromophores. Moreover, to determine the redox properties of these chromophores, cyclic voltammetry (CV) experiments were performed. After introducing the heteroatom to the benzene ring of the TAA donor, reduced energy gaps of 1.28 and 0.84 eV were obtained for chromophores T2 and T3, respectively, which was much lower than for chromophore T1 (ΔE = 1.46 eV). These chromophores showed excellent thermal stability with their decomposition temperatures all above 280 °C. Compared with results obtained from the chromophore without the heteroatom (T1), these new chromophores show better intramolecular charge-transfer (ICT) absorption. Most importantly, the high molecular hyperpolarizability (β) of these chromophores can be effectively translated into large electro-optic (EO) coefficients (r33) in the poled polymers. The electro-optic coefficient of poled films containing 25 wt% of these new chromophores doped in amorphous polycarbonate (APC) afforded values of 16, 58 and 95 pm V-1 at 1310 nm for chromophores T1-T3, respectively. High r33 values indicated that introducing heteroatom to the benzene ring of the TAA donor can efficiently improve the electron-donating ability, which improves the hyperpolarizability (β). The long-chain on the benzene ring of the TAA donor, acting as the isolation group, may reduce intermolecular electrostatic interactions, thus enhancing the macroscopic EO activity. These properties, together with the good solubility, suggest the potential use of these new chromophores as advanced material devices. This journal is
- Yang, Yuhui,Liu, Fenggang,Wang, Haoran,Bo, Shuhui,Liu, Jialei,Qiu, Ling,Zhen, Zhen,Liu, Xinhou
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p. 5297 - 5306
(2015/05/27)
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- Nitrogen dioxide-catalyzed electrophilic iodination of arenes
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Nitrogen dioxide is demonstrated to be an effective catalyst precursor for the iodination of alkoxy-substituted benzenes and naphthalenes. Different from the transition metal catalysts, nitrogen dioxide can be easily separated from the final products, and is free of heavy metal waste. Although the present catalyst precursor is toxic, it does not stain the final products due to its low-boiling character. No other reagents apart from 0.5 equiv. of iodine (I 2), 6.5 mol% nitrogen dioxide and acetonitrile solvent were used in the iodination, and basically all the iodine atoms in the iodine source were transferred to the iodination products, showing that the presented protocol is highly atom-economic and practical. Copyright
- Ren, Yun-Lai,Shang, Huantao,Wang, Jianji,Tian, Xinzhe,Zhao, Shuang,Wang, Qian,Li, Fuwei
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supporting information
p. 3437 - 3442
(2013/12/04)
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- Synthesis of diphenyl-diacetylene-based nematic liquid crystals and their high birefringence properties
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We synthesized two series of diphenyl-diacetylene (DPDA)-based materials with alkoxy and alkyl tails of length m (DPDA-OCm and DPDA-Cm, respectively), and measured their nematic-phase birefringence (Δn) as a function of wavelength and temperature. We found that Δn decreases with an increase in m, possibly by a dilution effect of the low-Δn alkyl tail. Further, of the two series, Δn was found to be relatively higher in the DPDA-OCm materials, with the highest value of 0.4 obtained for DPDA-OC1 at 550 nm at 10 °C below the isotropic-to-nematic transition temperature. Further, we observed the temperature dependence for Δn, which is proportional to the order parameter (s). From extrapolation to s = 1 (the perfect orientation state), it is speculated that the DPDA-O moiety has the potential to afford a very large Δn of 0.9. The Royal Society of Chemistry 2012.
- Arakawa, Yuki,Nakajima, Shunpei,Ishige, Ryohei,Uchimura, Makoto,Kang, Sungmin,Konishi, Gen-Ichi,Watanabe, Junji
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supporting information; experimental part
p. 8394 - 8398
(2012/07/28)
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- New compounds, pharmaceutical compositions and uses thereof
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The invention relates to new compounds of the formula I to their use as medicaments, to methods for their therapeutic use and to pharmaceutical compositions containing them.
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Page/Page column 51
(2012/09/05)
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- Solid-phase combinatorial synthesis of ester-type banana-shaped molecules by sequential palladium-catalyzed carbonylation
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16 five-ring ester-type Br-substituted banana-shaped molecules were synthesized in a combinatorial manner using palladium-catalyzed carbonylative esterification on a polymer-support and their mesophase behavior was investigated. The Royal Society of Chemistry 2009.
- Yoshida, Masahito,Doi, Takayuki,Kang, Sungmin,Watanabe, Junji,Takahashi, Takashi
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supporting information; experimental part
p. 2756 - 2758
(2009/12/03)
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- NOVEL HETEROCYCLIC AMIDE DERIVATIVES HAVING DIHYDROOROTATE DEHYDROGENASE INHIBITING ACTIVITY
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Novel heterocyclic amide derivatives having pharmacological effects, that is, compounds represented by the general formula (1) or salts thereof: (1) wherein X1-X2 is S-CH2 or the like; R1 is alkyl or the like; p is 0 to 7; R2 is hydrogen, alkyl, or the like; R3 is hydrogen, alkyl, or the like; Y1-Y2 is CH=CH or the like; R4 is halogeno, alkyl, or the like; q is 0 to 4; and R5 is halogeno, hydrogen, alkyl, or the like.
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Page/Page column 60
(2010/10/20)
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- Scope and mechanistic insights into the use of tetradecyl(trihexyl) phosphonium bistriflimide: A remarkably selective ionic liquid solvent for substitution reactions
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A survey of substitution reactions conducted in a phosphonium bistriflimide ionic liquid is presented. The results demonstrate high selectivity favoring substitution over typically competitive elimination and solvolytic processes even when challenging secondary and tertiary electrophiles are employed. The first reports of Kornblum substitution reactions in an ionic liquid are described that proceed with very high chemoselectivity in favor of nitro over nitroso products and elimi nation side products. The structure-reactivity study indicates that these reactions proceed through a narrow spectrum of pathways ranging from straight SN2 to a preassociation pathway along a saddle point that approaches the SN1 limit. The barrier to the formation of dissociated carbocations is attributed to the structural features of this ionic liquid that favor intervention of the associated nucleophile over dissociation, also preventing cross over to E1 processes. The lack of any basic entity in the phosphonium bistriflimide ionic liquid appears to prevent any potential base-mediated elimination reactions, which makes this a highly selective medium for use in general substitution reactions.
- McNulty, James,Nair, Jerald J.,Cheekoori, Sreedhar,Larichev, Vladimir,Capretta, Alfredo,Robertson
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p. 9314 - 9322
(2007/10/03)
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- One-pot preparation of arylalkynes by a tandem catalytic iodination of arenes and palladium-catalyzed coupling of iodoarenes with terminal alkynes
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Iodination of activated arenes by air-oxidation is carried out in the presence of catalytic bismuth salts at room temperature. Subsequently, the formed iodoarenes react with terminal alkynes to give arylalkynes under a selected palladium-catalyzed coupling condition in the same pot.
- Wan, Shun,Wang, Sunewang R.,Lu, Wenjun
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p. 4349 - 4352
(2007/10/03)
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- Solvent-Free Iodination of Arenes at Room Temperature
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Silica supported bismuth(III)nitrate pentahydrate [BNP-SiO2] was prepared under simple co-grinding condition. The iodination of aromatic compounds using BNP-SiO2 and molecular iodine under solvent-free conditions is described. The reaction occurred in the solid state at room temperature, yielding the corresponding mono-iodo derivative in good yields. However, less activated aromatics required longer reaction time with comparatively less yield.
- Alexander, Varughese M.,Khandekar, Amit C.,Samant, Shriniwas D.
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p. 1895 - 1897
(2007/10/03)
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- Synthesis and mesomorphic properties of some fluorinated benzoate liquid crystals
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Three series of [4-(4′-n-alkyloxyphenyl)acetylenyl]-2,6- difluorophenyl fluorinated benezoates and one series of fluorinated benzoates with 2,3,5,6-tetrafluorophenylene group and semi-perfluorocarbon chain have been synthesized. Their phase transition temperatures have been measured by texture observation in a polarizing microscope and confirmed by DSC. For the series without fluorocarbon chains, increasing the quantity of fluorosubstituents on the terminal phenyl groups decreased nematic stability (TN-I), but the breadth of the SmA phase range was increased. Lateral fluorosubstitution in the central group lowered the nematic stability (TN-I) and decreased the breadth of the SmA phase range. The series with semiperfluorocarbon chains were more likely to form SmA phases than the series with hydrogencarbon chains, and with the increasing of fluorosubstituents quantity on the terminal phenyl groups nematic and SmA stability (TN-I and TsmA-N) were both decreased.
- Yang, Yong Gang,Chen,Tang,Wen
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- Synthesis and mesomorphic properties of some fluoro-substituted benzoates
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Several series of fluoro-substituted benzoate liquid crystals have been synthesized. The results showed that the SmA phase is enhanced with the increasing of the degree of fluoro-substitution on the para- and meta-position of the terminal phenyl groups. And the molecules which have same molecular structural formula show nearly the same melting points. It is also discussed about the effect of the ester bond's direction on the mesomorphic properties.
- Yang,Tang,Gong,Wen
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p. 153 - 165
(2007/10/03)
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- Novel Ion Containing Liquid Crystals and Liquid Crystalline Main Chain Polymers Based on Trans-1,2-Bis(4-Pyridyl Ethylene) Mesogen
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Ion bearing liquid crystalline compounds based on trans-1,2-bis(4-pyridinium)ethylene were synthesized and studied.These compounds included low molecular mass analogues, twin model compounds and main chain ionomers.Most of these exhibited liquid crystallinity of the smectic type.As a general rule the introduction of charges into the mesogenic moiety increased the stability (transition temperature) of the mesophase.Large supercooling effects, broad mesophase intervals and tendency to polymorphism are common features of these ionic mesogenic compounds.In the case of twin model compounds a variety of smectic phases were observed.The nature of these was dependent on the nature of the counterion and the thermal history of the compound.Tosylate or p.toluene sulfonate counterions promoted a higher degree of order in smectic mesophases as well as higher transition tempertures compared to methylsulfonate counterions.A pronounced odd-even effect of the isotropisation temperature of the twin compounds was observed.Compounds with even numbered methylene spacers display higher transition temperatures than those with an odd spacer.Only polymers with methylsulfonate and toluenesulfonate counterions were found to exhibit both, thermotropic and lyotropic mesophases.Thermotropic mesophases were characterized as smectic mesophases of lower order (SA).The nature of lyotropic mesophases were not determined.High transition temperatures and concommitant oxydative crosslinking made the study of polymers with halogen counterions difficult.Polymers with halogen and perchlorate counterions were found fo be poorly soluble in water precluding the formation of lyotropic mesophases.The introduction of a few siloxane bonds into the flexible spacer joining the charged mesogen moieties has a dramatic effect on lowering the transition temparatures and making possible the study of mesophases up to their isotropisation temperature.Preliminary characterization of polymers with siloxane containing spacer and methylsulfonate/tosylate counterions suggest a smectic mesophase of lower order. - Keywords: Ion containing liquid crystals, liquid crystal ionomers
- Cheng, P.,Blumstein, A.,Subramanyam, S.
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- Iodination of Aromatic Ethers by Use of Benzyltrimethylammonium Dichloroiodate and Zinc Chloride
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The reaction of aromatic ethers with benzyltrimethylammonium dichloroiodate(1-) in acetic acid in the presence of zinc chloride at room temperature gave iodo-substituted aromatic ethers in good yields.
- Kajigaeshi, Shoji,Kakinami, Takaaki,Moriwaki, Masayuki,Watanabe, Masakazu,Fujisaki, Shizuo,Okamoto, Tsuyoshi
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p. 795 - 798
(2007/10/02)
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