- Combinatorial synthesis of new fluorescent scaffolds using click chemistry
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Azides and acetylenes are bio-orthogonal functional groups that can be readily coupled using copper(I)- or ruthenium(II)- catalyzed 1,3-dipolar cycloaddition reactions. Using non-fluorescent aromatic azides and aromatic acetylenes, covering a range of electron rich and poor building blocks, the Huisgen cycloaddition afford 1,4-disubstituted or 1,5-disubstituted 1,2,3-triazoles. Using a combinatorial approach by running reaction in parallel in polypropylene 96-well plates we discovered several new fluorescent 1,2,3-triazoles scaffolds. These compounds show diverse interactions with biomolecules that could find applications in biology in, for example, fluorescence microscopy or biomolecule quantification.
- Cleemann, Felix,Karuso, Peter,Kum-Cheung, Wendy Loa
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supporting information
(2021/12/08)
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- Cobalt-Catalyzed Hydroalkynylation of Vinylaziridines
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Transition metal-catalyzed hydroalkynylation reactions are efficient transformations allowing the straightforward formation of functionalized alkynes. Therein, we disclose the cobalt-catalyzed hydroalkynylation of vinylaziridines giving rise to both linea
- Biletskyi, Bohdan,Kong, Lingyu,Tenaglia, Alphonse,Clavier, Hervé
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supporting information
p. 2578 - 2585
(2021/03/18)
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- Near-Infrared Fluorescent Probes with Rotatable Polyacetylene Chains for the Detection of Amyloid-β Plaques
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The plaques of accumulated β-amyloid (Aβ) in the parenchymal brain are accepted as an important biomarker for the early diagnosis of Alzheimer's disease (AD). Many near-infrared (NIR) probes, which were based on the D-π-A structure and bridged by conjugat
- Zhang, Longfei,Gong, Xin,Tian, Chuan,Fu, Hualong,Tan, Hongwei,Dai, Jiapei,Cui, Mengchao
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p. 497 - 506
(2021/01/26)
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- Iron-Catalyzed Vinylzincation of Terminal Alkynes
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Organozinc reagents are among the most commonly used organometallic reagents in modern synthetic chemistry, and multifunctionalized organozinc reagents can be synthesized from structurally simple, readily available ones by means of alkyne carbozincation. However, this method suffers from poor tolerance for terminal alkynes, and transformation of the newly introduced organic groups is difficult, which limits its applications. Herein, we report a method for vinylzincation of terminal alkynes catalyzed by newly developed iron catalysts bearing 1,10-phenanthroline-imine ligands. This method provides efficient access to novel organozinc reagents with a diverse array of structures and functional groups from readily available vinylzinc reagents and terminal alkynes. The method features excellent functional group tolerance (tolerated functional groups include amino, amide, cyano, ester, hydroxyl, sulfonyl, acetal, phosphono, pyridyl), a good substrate scope (suitable terminal alkynes include aryl, alkenyl, and alkyl acetylenes bearing various functional groups), and high chemoselectivity, regioselectivity, and stereoselectivity. The method could significantly improve the synthetic efficiency of various important bioactive molecules, including vitamin A. Mechanistic studies indicate that the new iron-1,10-phenanthroline-imine catalysts developed in this study have an extremely crowded reaction pocket, which promotes efficient transfer of the vinyl group to the alkynes, disfavors substitution reactions between the zinc reagent and the terminal C–H bond of the alkynes, and prevents the further reactions of the products. Our findings show that iron catalysts can be superior to other metal catalysts in terms of activity, chemoselectivity, regioselectivity, and stereoselectivity when suitable ligands are used.
- Hu, Meng-Yang,Huang, Qiang,Su, Yu-Xuan,Sun, Wei,Wang, Wei-Na,Zhu, Shou-Fei
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supporting information
(2022/01/08)
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- Donor-acceptor substituted benzo-, naphtho- and phenanthro-fused norbornadienes
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The photochromic norbornadiene/quadricyclane (NBD/QC) couple has found interest as a molecular solar thermal energy (MOST) system for storage of solar energy. To increase the energy difference between the two isomers, we present here the synthesis of a selection of benzo-fused NBD derivatives that contain an aromatic unit, benzene, naphthalene or phenanthrene, fused to one of the NBD double bonds, while the carbon atoms of the other double bond are functionalized with donor and acceptor groups. The synthesis protocols involve functionalization of benzo-fused NBDs with bromo/chloro substituents followed by a subjection of these intermediates to a cyanation reaction (introducing a cyano acceptor group) followed by a Sonogashira coupling (introducing an arylethynyl donor group, -C≡CC6H4NMe2 or -C≡CC6H4OMe). While the derivatives have good absorption properties in the visible region (redshifted relative to parent system) in the context of MOST applications, they lack the ability to undergo NBD-to-QC photoisomerization, even in the presence of a photosensitizer. It seems that loss of aromaticity of the fused aromatics is too significant to allow photoisomerization to occur. The concept of destroying aromaticity of a neighboring moiety as a way to enhance the energy density of the NBD/QC couple thus needs further structural modifications, in the quest for optimum MOST systems.
- Fernandez, Lorette,Mans?, Mads,Moth-Poulsen, Kasper,Nielsen, Mogens Br?ndsted,Wang, Zhihang
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- Are alkynyl spacers in ancillary ligands in heteroleptic bis(diimine)copper(I) dyes beneficial for dye performance in dye-sensitized solar cells?
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The syntheses of 4,40-bis(4-dimethylaminophenyl)-6,60-dimethyl-2,20-bipyridine (1), 4,40-bis(4-dimethylaminophenylethynyl)-6,60-dimethyl-2,20-bipyridine (2), 4,40-bis(4-diphenylaminophenyl)-6,60-dimethyl-2,20-bipyridine (3), and 4,40-bis(4-diphenylaminophenylethynyl)-6,60-dimethyl-2,20-bipyridine (4) are reported along with the preparations and characterisations of their homoleptic copper(I) complexes [CuL2][PF6] (L = 1-4). The solution absorption spectra of the complexes exhibit ligand-centred absorptions in addition to absorptions in the visible region assigned to a combination of intra-ligand and metal-to-ligand charge-transfer. Heteroleptic [Cu(5)(Lancillary)]+ dyes in which 5 is the anchoring ligand ((6,60-dimethyl-[2,20-bipyridine]-4,40-diyl)bis(4,1-phenylene))bis(phosphonic acid) and Lancillary = 1-4 have been assembled on fluorine-doped tin oxide (FTO)-TiO2 electrodes in dye-sensitized solar cells (DSCs). Performance parameters and external quantum efficiency (EQE) spectra of the DSCs (four fully-masked cells for each dye) reveal that the best performing dyes are [Cu(5)(1)]+ and [Cu(5)(3)]+. The alkynyl spacers are not beneficial, leading to a decrease in the short-circuit current density (JSC), confirmed by lower values of EQEmax. Addition of a co-absorbent (n-decylphosphonic acid) to [Cu(5)(1)]+ lead to no significant enhancement of performance for DSCs sensitized with [Cu(5)(1)]+. Electrochemical impedance spectroscopy (EIS) has been used to investigate the interfaces in DSCs; the analysis shows that more favourable electron injection into TiO2 is observed for sensitizers without the alkynyl spacer and confirms higher JSC values for [Cu(5)(1)]+,.
- Becker, Mariia,Constable, Edwin C.,Housecroft, Catherine E.,Risi, Guglielmo
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- Novel synthetic strategy towards subphthalocyanine-functionalized acetylenic scaffolds: Via various dibromo-enynes
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Boron subphthalocyanine (SubPc) is a strong chromophore with interesting applications in the field of functional materials and can be synthetically modified in both the peripheral and axial positions, allowing tuning of optical and redox properties. Herei
- Brol?s, Line,Kilde, Martin Dr?hse,Nielsen, Mogens Br?ndsted
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p. 6077 - 6085
(2020/10/27)
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- Fe-Catalyzed Selective Cyclopropanation of Enynes under Photochemical or Thermal Conditions
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The nucleophilic Fe-complex Bu4N[Fe(CO)3(NO)] (TBA[Fe]) catalyzes the cyclopropanation of enynes to substituted propargyl cyclopropanes using diazoesters as carbene surrogates. The catalyst can be activated either thermally in the presence of catalytic amounts of 4-nitroanisole or under photochemical conditions. Cyclopropanation occurs selectively at the enyne moiety; alternative olefinic moieties remain intact.
- Picher, Marie-Idrissa,Plietker, Bernd
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supporting information
p. 340 - 344
(2020/01/11)
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- A Porous and Solution-Processable Molecular Crystal Stable at 200 °c: The Surprising Donor-Acceptor Impact
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We report a curious porous molecular crystal that is devoid of the common traits of related systems. Namely, the molecule does not rely on directional hydrogen bonds to enforce open packing, and it offers neither large concave faces (i.e., high internal f
- Cheng, Shengxian,Ma, Xiaoxia,He, Yonghe,He, Jun,Zeller, Matthias,Xu, Zhengtao
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p. 7411 - 7419
(2019/12/02)
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- Copper-Mediated Deacylative Coupling of Ynones via C-C Bond Activation under Mild Conditions
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The intermolecular deacylative coupling of unstrained ynones via C-C bond activation was accomplished by a CuCl-bpy system under mild reaction conditions. This protocol features facile cleavage of the C-C bond at room temperature, broad substrate scope, and efficient construction of important symmetric and unsymmetrical 1,3-diyne adducts through homo or cross coupling of ynones, respectively. The preliminary mechanistic investigations indicated that an acyl copper(III) complex is likely involved in this process.
- Feng, Lili,Hu, Tingjun,Zhang, Saisai,Xiong, Heng-Ying,Zhang, Guangwu
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supporting information
p. 9487 - 9492
(2019/12/02)
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- UiO-type metal-organic frameworks with NHC or metal-NHC functionalities for: N-methylation using CO2 as the carbon source
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We demonstrate the first metal-organic framework (MOF) that catalyzes N-methylation of amines using 1 atm CO2 and phenylsilane under ambient conditions. Compared with its homogeneous analog, the incorporation of N-heterocyclic carbene (NHC) into the MOF provides more efficient catalysis with improved reaction kinetics, turnover numbers and recyclability. Moreover, the metalated NHC functionalized MOF achieves direct N-methylation of amines bearing carboxylate moieties, which are common building blocks in pharmaceutical chemistry.
- Zhang, Xu,Jiang, Yilin,Fei, Honghan
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supporting information
p. 11928 - 11931
(2019/10/11)
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- Reversible mechanofluorochromism of aniline-terminated phenylene ethynylenes
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Seven three-ring phenylene-ethynylene (PE) structural analogs, differing only in the lengths of alkyl chains on terminal aniline substituents, show 50-62 nm bathochromic shifts in emission maxima in response to mechanical force (mechanofluorochromism, MC)
- Sharber, Seth A.,Shih, Kuo-Chih,Mann, Arielle,Frausto, Fanny,Haas, Terry E.,Nieh, Mu-Ping,Thomas, Samuel W.
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p. 5415 - 5426
(2018/06/27)
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- Synthesis, Crystal Structures, and Solid-State Polymerization of 8?[4-(Dimethylamino)phenyl]octa-5,7-diynyl Carbamates
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Six butadiyne monomers with (dimethylamino)phenyl and N-substituted urethane substituents were synthesized and their crystal structures and solid-state polymerization were investigated. In five of the six monomers, directions of the butadiyne stacking and
- Ikeshima, Masataka,Katagiri, Hiroshi,Fujiwara, Wataru,Tokito, Shizuo,Okada, Shuji
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p. 5991 - 6000
(2018/09/27)
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- TETRAHYDROPYRIDINE DERIVATIVES AND THEIR USE AS ANTIBACTERIAL AGENTS
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The present disclosure relates to a novel tetrahydropyridine derivative compound, a stereoisomer thereof, or a pharmaceutically acceptable salt thereof, methods for preparing the compounds, methods for inhibiting UDP-3-O—(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase (LpxC), methods for treating Gram-negative bacterial infections, the use of the compounds for the preparation of therapeutic medicaments for treating Gram-negative bacterial infections, and pharmaceutical compositions for prevention or treatment of Gram-negative bacterial infections, which contain the compounds. The compounds represented by formula I, stereoisomers thereof or pharmaceutically acceptable salts thereof according to the present disclosure can exhibit excellent effects on the treatment bacterial infections.
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Paragraph 0330-0333; 0334-0336
(2018/04/20)
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- Multi-color photoluminescence induced by electron-density distribution of fluorinated bistolane derivatives
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The aim of this study was to design and develop new fluorinated light-emitting materials with multi-color photoluminescence that are not limited by their states. For this purpose, fluorinated bistolanes with an amino substituent, such as carbazol-9-yl, di
- Yamada, Shigeyuki,Morita, Masato,Konno, Tsutomu
-
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- Calcium carbide catalytically activated with tetra-: N -butyl ammonium fluoride for Sonogashira cross coupling reactions
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We report a novel method for the direct synthesis of mono- and bis-arylated alkynes utilizing catalytically activated CaC2 as the alkyne component. This fluoride-activated cross coupling reaction provides advantages over existing methods regarding operational simplicity, use of readily available starting materials, and low cost.
- Hosseini, Abolfazl,Pilevar, Afsaneh,Hogan, Eimear,Mogwitz, Boris,Schulze, Anne S.,Schreiner, Peter R.
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p. 6800 - 6807
(2017/08/22)
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- Catalyst-free N-methylation of amines using CO2
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Recently, utilizing CO2 as a methylation reagent to construct functional chemicals has attracted significant attention. However, the conversion of CO2 is still a challenge due to its inherent inertness. In this study, we have developed a catalyst-free N-methylation of amines to prepare numerous methylamines using CO2 as a methyl source. By utilizing 2 eq. PhSiH3 as the reductant, amines could undergo N-methylation under 1 atm of CO2 in DMF at 90 °C. Aliphatic and aromatic amines were compatible, generating the desired products in up to 95% yield.
- Niu, Huiying,Lu, Lijun,Shi, Renyi,Chiang, Chien-Wei,Lei, Aiwen
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supporting information
p. 1148 - 1151
(2017/02/05)
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- Betaine Catalysis for Hierarchical Reduction of CO2 with Amines and Hydrosilane To Form Formamides, Aminals, and Methylamines
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An efficient, sustainable organocatalyst, glycine betaine, was developed for the reductive functionalization of CO2 with amines and diphenylsilane. Methylamines and formamides were obtained in high yield by tuning the CO2 pressure and reaction temperature. Based on identification of the key intermediate, that is, the aminal, an alternative mechanism for methylation involving the C0 silyl acetal and aminal is proposed. Furthermore, reducing the CO2 amount afforded aminals with high yield and selectivity. Therefore, betaine catalysis affords products with a diversified energy content that is, formamides, aminals and methylamines, by hierarchical two-, four- and six-electron reduction, respectively, of CO2 coupled with C?N bond formation.
- Liu, Xiao-Fang,Li, Xiao-Ya,Qiao, Chang,Fu, Hong-Chen,He, Liang-Nian
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supporting information
p. 7425 - 7429
(2017/06/13)
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- Efficient Microwave-Assisted Synthesis of Sonogashira-Coupled Perylene Monoimide Derivatives: Impact of Electron-Donating Groups on Optoelectronic Properties
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An efficient microwave-assisted Sonogashira-coupling protocol for the synthesis of peri-functionalized perylene monoimide dye derivatives was developed. This method was found to be significantly faster than the conventional coupling method and provided pr
- Sharma, Vikas,Chandra, Falguni,Sahoo, Dhananjaya,Koner, Apurba L.
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p. 6901 - 6905
(2017/12/26)
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- Catalyst-free hydrochlorination protocol for terminal arylalkynes with hydrogen chloride
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We present a simple and straightforward protocol for hydrochlorination of terminal arylalkynes to vinyl chlorides using hydrogen chloride under mild reaction conditions. This protocol does not involve any metal catalysts or additives. It is simple, inexpensive, and easy to prepare, and exhibits good reaction activity. The hydrochlorination proceeds smoothly to yield unique regioselective products via the Markovnikov addition rule.
- Xu, Cai-Xia,Ma, Cun-Hua,Xiao, Fu-Rong,Chen, Hong-Wei,Dai, Bin
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supporting information
p. 1683 - 1685
(2016/11/12)
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- Rapid access to unsymmetrical tolanes and alkynones by sequentially palladium-catalyzed one-pot processes
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Alkynones as well as unsymmetrically substituted tolanes (diarylalkynes) can be rapidly generated in a one-pot fashion via sequential palladium catalysis. Terminal alkynes, formed in situ by protecting-group free palladium-catalyzed coupling of aryl iodides with ethynyl magnesium bromide, are subsequently transformed by Sonogashira coupling with aryl halides or aroyl chlorides to furnish unsymmetrically substituted alkynes in good to excellent yields.
- G?tzinger, Alissa C.,Müller, Thomas. J. J.
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supporting information
p. 3498 - 3500
(2016/04/19)
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- Pyrimidine or pyridine pyridine ketone compound and its preparation method and application (by machine translation)
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The invention discloses a kind of type I of the pyrimidine or pyridine pyridine ketone compound and its preparation and application, which belongs to the technical field of pharmaceutical preparation. The compounds have high-efficient and selectively inhibit the cell cycle dependent kinases (Cdks) CDK4 and CDK6 active, and then by inhibiting CDK4/CDK6 prevent tumor cell division. Therefore, the compounds of this invention can be used for CDK4 and CDK6 the involved in cell cycle control disorders result in various diseases, especially suitable for the treatment of malignant tumors. (by machine translation)
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Paragraph 0303
(2016/10/09)
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- Position of substitution: A facile way to tune the spectroscopic properties of dimethylamino-substituted arylene-ethynylenes
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A series of dimethylamino-substituted arylene-ethynylenes were synthesised by Sonogashira coupling reactions and characterised by the methods of 1H, 13C NMR, UV-Vis, fluorescence, HRMS and theoretical calculations. Effects on spectroscopic properties caus
- Fang, Jing-Kun,Sun, Tengxiao,Fang, Yu,Xu, Zhimin,Zou, Hui,Liu, Yuan,Ge, Fangting
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p. 487 - 491
(2015/11/03)
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- Systematic variation of cyanobuta-1,3-dienes and expanded tetracyanoquinodimethane analogues as electron acceptors in photoactive, rigid porphyrin conjugates
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We report on a homologous series of nine electron donor-acceptor systems featuring push-pull chromophores as electron acceptors, which are accessible by a cycloaddition-retroelectrocyclization (CA-RE) reaction. The conjugates comprise a ZnII porphyrin as electron donor, which is connected through either a rigid phenylene-ethynylene-phenylene (PEP)-bicyclo[2.2.2]octane or a PEP-trans-decahydroquinoline spacer to different anilino-substituted multicyanobutadienes or extended tetracyanoquinodimethane analogues with first reduction potentials ranging from-1.78 to-0.58 V vs. Fc+/Fc. Characterization of the conjugates includes X-ray crystallography, electrochemistry, DFT calculations, and fluorescence spectroscopy. The extent of ZnII porphyrin fluorescence quenching correlates with the strength of the electron acceptor. Overall, we demonstrate the synthetic feasibility of rationally modulating the acceptor strength by means of the CA-RE reaction in geometrically well-defined electron donor-acceptor conjugates.
- Urner, Lorenz M.,Sekita, Michael,Trapp, Nils,Schweizer, W. Bernd,W?rle, Michael,Gisselbrecht, Jean-Paul,Boudon, Corinne,Guldi, Dirk M.,Diederich, Franois
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supporting information
p. 91 - 108
(2015/02/19)
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- Benzobisimidazole Cruciform Fluorophores
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A series of 11 cross-conjugated cruciform fluorophores based on a benzobisimidazole nucleus has been synthesized and characterized. Like in their previously reported benzobisoxazole counterparts, the HOMOs of these new fluorophores are localized along the vertical bisethynylbenzene axes, while their LUMOs remain relatively delocalized across the molecule, except in cruciforms substituted with electron-withdrawing groups along the vertical axis. Benzobisimidazole cruciforms exhibit a pronounced response to deprotonation in their UV/vis absorption and emission spectra, but their response to protonation is significantly attenuated. (Chemical Equation Presented).
- Le, Ha T. M.,El-Hamdi, Nadia S.,Miljani?, Ognjen ?.
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p. 5210 - 5217
(2015/05/27)
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- A twisted-intramolecular-charge-transfer (TICT) based ratiometric fluorescent thermometer with a mega-Stokes shift and a positive temperature coefficient
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The fluorescence intensity of N,N-dimethyl-4-((2-methylquinolin-6-yl)ethynyl)aniline exhibits an unusual intensification with increasing temperature, by activating more vibrational bands and leading to stronger TICT emissions upon heating in dimethyl sulfoxide. Based on the different temperature dependence at various wavelengths, as shown in the TICT fluorescence spectrum, this dye can be employed to ratiometrically detect temperature.
- Cao, Cheng,Liu, Xiaogang,Qiao, Qinglong,Zhao, Miao,Yin, Wenting,Mao, Deqi,Zhang, Hui,Xu, Zhaochao
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supporting information
p. 15811 - 15814
(2015/01/08)
-
- Amino derivatives of indolone-N-oxide: Preparation and antiplasmodial properties
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There is an urgent need for new antimalarial drugs with novel mechanisms of action on novel targets. Indolone-N-oxides (INODs) display antimalarial properties in vitro and in vivo, but identified leads such as 6-(4-chloro-phenyl)-5-oxy-[1,3]dioxolo[4,5-f]
- Najahi, Ennaji,Rakotoarivelo, Nambinina V.,Valentin, Alexis,Nepveu, Fran?oise
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p. 369 - 375
(2014/03/21)
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- 2-Aryl-3H-indol-3-ones: Synthesis, electrochemical behaviour and antiplasmodial activities
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The synthesis of indolone derivatives and their antiplasmodial activity in vitro against Plasmodium falciparum at the blood stage are described. The 2-aryl-3H-indol-3-ones were synthesized via deoxygenation of indolone-N-oxides. Electrochemical behaviour, antiplasmodial activity and cytotoxicity on human tumor cell lines were compared to those of indolone-N-oxides. The antiplasmodial IC50 (concentrations at 50% inhibition) of these compounds ranged between 49 and 1327 nM. Among them, the 2-(4-dimethylaminophenyl)-5-methoxy- indol-3-one, 7, had the best antiplasmodial activity in vitro (IC50 = 49 nM; FcB1 strain) and selectivity index (SI (CC50 MCF7/IC 50 FcB1) = 423.4). Thus, the hits identified in this deoxygenated series correspond to their structural homologs in the N-oxide series with comparable electrochemical behaviour at the nitrogen-carbon double bond.
- Najahi, Ennaji,Valentin, Alexis,Fabre, Paul-Louis,Reybier, Karine,Nepveu, Fran?oise
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p. 269 - 274
(2014/04/17)
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- Elongation of the molecular probe DDNP with phenylethynylidene or phenyldiazenylidene spacers
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In this work, we report the synthesis, X-ray structures, and optical properties of two DDNP analogs containing an unsaturated spacer inserted between the donor N,N-dimethylamino group and the naphthalene ring. The new compounds have longer distances betwe
- Rejc, Luka,Fabris, Jan,Adrovi?, Armin,Kasuni?, Marta,Petri?, Andrej
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supporting information
p. 1218 - 1221
(2014/02/14)
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- L-shaped benzimidazole fluorophores: Synthesis, characterization and optical response to bases, acids and anions
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Nine L-shaped benzimidazole fluorophores have been synthesized, computationally evaluated and spectroscopically characterized. These "half-cruciform" fluorophores respond to bases, acids and anions through changes in fluorescence that vary from moderate t
- Lirag, Rio Carlo,Le, Ha T. M.,Miljanic, Ognjen S.
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p. 4304 - 4306
(2013/06/05)
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- Synthesis and Solid-State Polymerization of 4-(Dimethylamino) phenylbutadiyne Derivatives and Their Charge-Transfer Complexes
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(Five urethane derivatives of 8-[4-(dimethylamino)phenyl]octa-5,7-diyn-1-ol were synthesized. They could be polymerized in the solid state to give conjugated backbones although structural regularity seemed to be not so high. Formability of chargetransfer
- Ishii, Shinji,Kaneko, Shota,Tatewaki, Yoko,Okada, Shuji
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- Synthesis, characterization, and solid-state polymerization of cross-conjugated octatetraynes
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Two series of cross-conjugated 1,3,5,7-octatetraynes (1a-1l and 6a-6d) have been synthesized. UV-vis spectroscopic analysis shows that pendent groups connected to the cross-conjugated skeleton have little effect on the λmax energies, irrespective of whether the groups are electron withdrawing or donating. A number of the isolated products readily give crystals suitable for X-ray crystallography, and the solid-state structural properties of five derivatives (1k, 1l, 6a, 6c, and 6d) have been examined by X-ray crystallographic analysis. Parallel packing of the polyynes in the solid state indicates that four of the five samples are potentially suitable for topochemical polymerization, based on solid-state packing parameters θ, R, and d. Attempts to effect a solid-state reaction have been explored through UV-vis and γ-ray irradiation as well as thermal heating. The course of these reactions was monitored by differential scanning calorimetry (DSC) analysis, as well as UV-vis and solid-state 13C NMR spectroscopy (for 1d, 1j, 1k, and 6d), which offered evidence of polymer formation from these reactions. Structural determination of the product(s), however, remains elusive.
- Zhao, Yuming,Luu, Thanh,Bernard, Guy M.,Taerum, Tyler,McDonald, Robert,Wasylishen, Roderick E.,Tykwinski, Rik R.
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p. 994 - 1014
(2013/02/22)
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- Palladium-catalyzed coupling between aryl halides and trimethylsilylacetylene assisted by dimethylaminotrimethyltin
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Palladium-catalyzed coupling between aryl halides, especially less reactive ones or N-heteroaryls, and trimethylsilylacetylene in the presence of dimethylaminotrimethyltin generated the coupled products in high yields. The reaction does not need CuI and base as auxiliary agents.
- Cai, Liangzhen,Yang, Dujuan,Sun, Zhonghua,Tao, Xiaochun,Cai, Lisheng,Pike, Victor W.
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experimental part
p. 1059 - 1062
(2012/01/04)
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- Benzobisoxazole cruciforms: Heterocyclic fluorophores with spatially separated frontier molecular orbitals
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We report the synthesis of nine conjugated cruciform-shaped molecules based on the central benzo[1,2-d:4,5-d′]bisoxazole nucleus, at which two conjugated currents intersect at a ~90° angle. Cruciforms' substituents were varied pairwise among the electron-
- Lim, Jaebum,Albright, Thomas A.,Martin, Benjamin R.,Miljanic, Ognjen S.
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experimental part
p. 10207 - 10219
(2012/02/03)
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- Benzothiazole-based fluorophores of donor-π-acceptor-π-donor type displaying high two-photon absorption
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A series of novel heterocycle-based dyes with donor-π-bridge-acceptor- π-bridge-donor (D-π-A-π-D) structural motif, where benzothiazole serves as an electron-withdrawing core, have been designed and synthesized via palladium-catalyzed Sonogashira and Suzuki-type cross-coupling reactions. All the target chromophores show strong one-photon and two-photon excited emission. The maximum two-photon absorption (TPA) cross sections ΔTPA of the prepared derivatives bearing diphenylamino functionalities occur at wavelengths ranging from 760 to 800 nm and are as large as ~900-1100 GM. One- and two-photon absorption characteristics of the title dyes have also been investigated by using density functional theory (DFT) and the structure-property relationships are discussed. The TPA cross sections calculated by means of quadratic response time-dependent DFT using the Coulomb-attenuated CAM-B3LYP functional support the experimentally observed trends within the series, as well as higher ΔTPA values of the title compounds compared to those of analogous fluorene or carbazole-derived dyes. In contrast, the traditional B3LYP functional was not successful in predicting the observed trend of TPA cross sections for systems with different central cores. In general, structural modification of the π-bridge composition by replacement of ethynylene (alkyne) with E-ethenylene (alkene) linkages and/or replacement of dialkylamino electron-donating edge substituents by diarylamino ones results in an increase of ΔTPA values. The combination of large TPA cross sections and high emission quantum yields makes the title benzothiazole-based dyes attractive for applications involving two-photon excited fluorescence (TPEF).
- Hrobarikova, Veronika,Hrobarik, Peter,Gajdos, Peter,Fitilis, Ioannis,Fakis, Mihalis,Persephonis, Peter,Zahradnik, Pavol
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experimental part
p. 3053 - 3068
(2010/07/15)
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- A polyanionic dendritic fluorophore for selective detection of Hg 2+ in triton X-100 aqueous media
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A serles of water-soluble fluorescent dendritic compounds composed of phenylene-ethynylene repeating units and anionic carboxylate or catlonlc ammonium peripheral groups were synthesized. The first generation fluorescent dendrlmer containing nine phenylene-ethynylene units and six carboxylate peripheral groups exhibited a highly selective fluorescence quenching by Hg 2+ Ions. The Stern-Volmer constant (K8v) was 33,700 M -1 In aqueous media In the presence of Triton X-100 surfactant.
- Niamnont, Nakorn,Siripornnoppakhun, Warathip,Rashatasakhon, Paltoon,Sukwattanasinitt, Mongkol
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supporting information; experimental part
p. 2768 - 2771
(2009/11/30)
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- Synthesis and properties of novel liquid crystalline materials with super high birefringence: styrene monomers bearing diacetylenes, naphthyl, and nitrogen-containing groups
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Three new liquid crystal asymmetrical styrene monomers bearing diacetylenes, naphthyl, and nitrogen-containing groups were successfully synthesized from 2-(bromoethynyl)-6-(hexyloxy)naphthalene, 4-(4-bromo-2-vinylphenyl)-2-methylbut-3-yn-2-ol, and derivat
- Guan, Xiao-Lin,Zhang, Lan-Ying,Zhang, Zhen-Lin,Shen, Zhihao,Chen, Xiao-Fang,Fan, Xing-He,Zhou, Qi-Feng
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body text
p. 3728 - 3732
(2009/09/06)
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- New push-pull chromophores featuring TCAQ (11,11,12,12-Tetracyano-9,10- anthraquinodimethane) and other dicyanovinyl acceptors
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Stable, highly colored push-pull chromophores with NMe2 donor and C=C(CN)2 acceptor moieties, featuring intense intramolecular charge-transfer (CT) bands in the UV/Vis spectra, are reported. In an attempt to prepare the quinoid pushpull systems 2, chromophores 10 and 11, with a central cyclohexene spacer, were obtained and characterized by X-ray analysis. A series of donor-substituted TCAQ (11,11,12,12-tetracyano-9,10-anthraquinodimethane) derivatives were synthesized, using the Knoevenagel condensation between appropriately functionalized anthraquinones and malononitrile, mediated by the Lehnert reagent (TiCl4/pyridine), as the key step. HCl addition to triple bonds was observed when this transformation was applied to alkynylated anthraquinones. Electrochemical studies by cyclic voltammetry (CV) and rotating-disk voltammetry (RDV) showed that introduction of donor substituents into the TCAQ core of 25, 26, and 31 shifts the first reduction potential to more negative values, while chromophores bearing guanidine moieties (27, 28) displayed a specific and complex redox behavior. Both electrochemical and UV/Vis data provide good evidence that D-A conjugation is more efficient through olefinic (in 10) than through acetylenic (in 37) spacers. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Bures, Filip,Bernd Schweizer,Boudon, Corinne,Gisselbrecht, Jean-Paul,Gross, Maurice,Diederich, Francois
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experimental part
p. 994 - 1004
(2009/04/11)
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- Terminal alkynes from aldehydes via dehydrohalogenation of (Z)-1-iodo-1-alkenes with TBAF
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Terminal alkynes were prepared in near quantitative yields via dehydrohalogenation of (Z)-1-iodo-1-alkenes with tetrabutylammonium fluoride (TBAF) under mild conditions. The methodology was expanded to include a one-pot, direct synthesis of terminal alkynes from aldehydes without the necessity of isolating and purifying the intermediate iodoalkene.
- Beshai, Mira,Dhudshia, Bhartesh,Mills, Ryan,Thadani, Avinash N.
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supporting information; experimental part
p. 6794 - 6796
(2009/04/07)
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- A novel reaction of 7,7,8,8-tetracyanoquinodimethane (TCNQ): Charge-transfer chromophores by [2 + 2] cycloaddition with alkynes
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A series of donor-acceptor molecules, featuring intense low-energy intramolecular charge-transfer bands, was prepared by regioselective [2 + 2] cycloaddition between 7,7,8,8-tetracyanoquinodimethane (TCNQ) and N,N-dialkylanilino-substituted (DAA-substitut
- Kivala, Milan,Boudon, Corinne,Gisselbrecht, Jean-Paul,Seiler, Paul,Gross, Maurice,Diederich, Francois
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p. 4731 - 4733
(2008/09/17)
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- New fluorophores with rod-shaped polycyano π-conjugated structures: Synthesis and photophysical properties
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Novel rod-shaped polycyano-oligo(phenyleneethynylene)s were synthesized by Pd cross-coupling reaction. Polycyano groups were found to greatly improve the emission efficiency (Φf) of OPEs. By the end donor modification, we achieved the creation of very intense blue light-emitting fluorophore with the SMe group (Φf) = 0.972, log ε 4.89, λ em 455 nm) and very intense yellow light-emitting fluorophore with the NMe2 group (Φf = 0.999, log ε 4.75, λem 555 nm). Contrasting Φf solvent dependency of 6 and 7 and a linear relationship between Φf and σp-X over the whole region of σp-X were also found.
- Yamaguchi, Yoshihiro,Ochi, Takanori,Wakamiya, Tateaki,Matsubara, Yoshio,Yoshida, Zen-Ichi
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p. 717 - 720
(2007/10/03)
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- Systematic studies on photoluminescence of oligo(arylene-ethynylene)s: Tunability of excited states and derivatization as luminescent labeling probes for proteins
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Functionalized oligo(phenylene-ethynylene)s (OPEs) with different conjugation lengths, p-X(C6H4C≡C) nSiMe3 (n = 1-4; X = NH2, NMe2, H) were synthesized by Sonogashira coupling of (phenylene-ethynylene)s and 1-iodo-4-(trimethylsilylethynyl)benzene, followed by desilylation of the p-substituted (trimethylsilylethynyl)benzenes with potassium hydroxide. The photoluminescent properties for the OPE series with different chain lengths and their solvatochromic responses were examined. The absorption maxima were red-shifted with increasing numbers of -(C6H4C≡C)- units (n), and a linear plot of the absorption energy maxima vs. 1/n was obtained for each series. The emission spectra in dichloromethane showed a broad and structureless band, the energies of which (in wavenumbers) also fit linearly with 1/n. Both the absorption and emission wavelength maxima of the NH2- and NMe2-substituted OPEs exhibited significant solvent dependence, whereas the parent OPEs (X = H) showed only minor shifts of the λmax values in different solvents. Substituent effects upon the photoluminescent characteristics of the OPEs and the tunability of the excited states were examined with the p-X(C6H4C≡C) nSiMe3 (n = 2, 3; X = NH2, NMe2, H, SMe, OMe, OH, and F) series. The H- and F-substituted counterparts exhibited high-energy vibronically structured emissions attributed to the 3(ππ*) excited states of the (arylene-ethynylene) backbone. For compounds bearing NH2 and NMe2 groups, a broad red-shifted emission with a remarkable Stokes shift from the respective absorption maximum was observed, which can be assigned to an n → π* transition. The n → π* assignment was supported by MO calculations on the model compounds p-X(C6H4C≡C) 2SiH3 (X = NH2, H). Functionalization of the oligo(arylene-ethynylene)s with the N-hydroxysuccinimidyl (NHS) moiety enabled covalent attachment of the fluorophore to HSA protein molecules. A series of fluorescent labels, namely p-X(C6H4C≡C) n-C6H4NHS, (n = 1, X = NH2, NMe 2, SMe, OMe, OH, F; n = 2, X = NH2, NMe2) and p-Me2NC6H4C≡C(C4H 2S)-C≡CC6H4NHS were synthesized, and their conjugates with HSA (human serum albumin) were characterized by MALDI-TOF mass spectrometry, UV/Vis absorption spectroscopy, and gel electrophoresis. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
- Zhi, Yong-Gang,Lai, Siu-Wai,Chan, Queenie K.-W.,Law, Yuen-Chi,Tong, Glenna S.-M.,Che, Chi-Ming
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p. 3125 - 3139
(2007/10/03)
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- Stereospecific synthesis of conjugated (1E,3E)- and (1Z,3Z)-1,4-di(n-N,N- dimethylaminophenyl)-1,3-butadienes from 2-chloro-1-(n-N,N-dimethylaminophenyl) ethenes: Fluorescence properties
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The conjugated 1,4-di(n-N,N-dimethylaminophenyl)-1,3-butadienes (n=o-, m-, p-) were efficiently synthesised by homocoupling of the appropriate 2-chloro-1-(n-N,N-dimethylaminophenyl)ethene (n=o-, m-, p-) with stoichiometric amounts of zerovalent nickel com
- Rodriguez, J. Gonzalo,Tejedor, J. Luis,Rumbero, Angel,Canoira, Laureano
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p. 3075 - 3080
(2007/10/03)
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- Synthesis of conjugated 2 and 2,5-(ethenyl) and (ethynyl)phenylethynyl thiophenes: Fluorescence properties
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Nano conjugated thienylethenyl and thienylethynyl compounds with controlled structure and dimensions have been efficiently prepared, by heterocoupling reaction between 1,4-(thienylethynyl)phenylacetylene (or thienylethenyl) phenylacetylene and 2- or 2,5-dihalothiophene. Conjugated 1,4-di(2- thienylethynylphenyl)- (or 2-thienylethenylphenyl)-1,3-butadiyne were obtained by the homocoupling of the terminal acetylenes in excellent yield. The end-capped (N,N-dimethylaminophenyl)- and [3,5-di(trimethylsilylethynyl)-1- ethynyl]-2,5-di(phenylethynyl)nthiophene were obtained by the heterocoupling between the corresponding terminal acetylene and 2,5-di(iodo)thiophene, catalyzed by the bis(triphenylphosphine)palladium and cuprous iodide system in excellent yield.
- Rodriguez, J. Gonzalo,Esquivias, Jorge,Lafuente, Antonio,Rubio, Laura
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p. 3112 - 3122
(2007/10/03)
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- Hammett analysis of selective thyroid hormone receptor modulators reveals structural and electronic requirements for hormone antagonists
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Selective thyroid hormone modulators that function as isoform-selective agonists or antagonists of the thyroid hormone receptors (TRs) might be therapeutically useful in diseases associated with aberrant hormone signaling. The most potent thyroid hormone
- Nguyen, Ngoc-Ha,Apriletti, James W.,Baxter, John D.,Scanlan, Thomas S.
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p. 4599 - 4608
(2007/10/03)
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- Synthesis and non-linear optical properties of new ionic species: Tolan and diphenylbutadiyne with trimethylammonio and dimethylamino groups
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As new ionic organic species for second-order non-linear optical (NLO) materials, 4-{[4-(dimethylamino)phenyl]ethynyl)phenyltrimethylarnmonium iodide (1a), 4-{[4-(dimethylamino)phenyl]butadiynyl}phenyltri-methylammoniura iodide (2a) and their derivatives
- Umezawa, Hirohito,Okada, Shuji,Oikawa, Hidetoshi,Matsuda, Hiro,Nakanishi, Hachiro
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p. 468 - 472
(2007/10/03)
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- Synthesis and crystal structures of phenylethynylpyridinium derivatives for second-order nonlinear optics
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Several salts of 1-methyl-4-[4-(dimethylamino)phenylethynyl]pyridinium 1, whose ethenyl analogue 2 is the cation of DAST (1-methyl-4-{2-[4-(dimethylamino) phenyl]ethenyl}pyridinium p-toluenesulfonate), were synthesized, and these properties were investiga
- Umezawa, Hirohito,Okada, Shuji,Oikawa, Hidetoshi,Matsuda, Hiro,Nakanishi, Hachiro
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p. 344 - 348
(2007/10/03)
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- Synthesis and electrogenerated chemiluminescence of donor-substituted phenylquinolinylethynes and phenylisoquinolinylethynes: Effect of positional isomerism
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In furtherance of our research on the design, synthesis and study of electrogenerated chemiluminescence (ECL) of new donor substituted phenylquinolinylethynes, we report here more new series with the aim of studying the effect of positional isomerism on their overall photophysical properties with a special focus on ECL. For this study we have chosen 2-, 3-, and 4-(p-substituted phenyl)ethynylquinolines, and 1- and 4-(p-substituted phenyl)ethynylisoquinolines. These ethynes were synthesized in good yields by modified Sonogashira coupling of the corresponding terminal alkyne with the respective haloquinolines. The photophysical properties and ECL were studied in acetonitrile solvent and the various results are discussed.
- Elangovan, Arumugasamy,Yang, Shu-Wen,Lin, Jui-Hsien,Kao, Kuo-Ming,Ho, Tong-Ing
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p. 1597 - 1602
(2007/10/03)
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- Synthesis and optical properties of conjugated N,N-dimethyl and thienyl end-capped 2,5-(arylethynyl)thiophene oligomer structures
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End-capped (N,N-dimethylaminophenyl) and 2′-thienylethynyl 2,5-thiophene oligomer structures were synthesized by heterocoupling between the terminal acetylenes such as: p-(N,N-dimethylaminophenyl)ethyne (3) [or 1-(p-(N,N-dimethylaminophenyl)-2-p-(ethynylp
- Rodríguez, J. Gonzalo,Lafuente, Antonio,Rubio, Laura,Esquivias, Jorge
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p. 7061 - 7064
(2007/10/03)
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- Sonogashira coupling reaction with diminished homocoupling
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(Matrix presented) The side product from homocoupling reaction of two terminal acetylenes in the Sonogashira reaction can be reduced to about 2% using an atmosphere of hydrogen gas diluted with nitrogen or argon. Terminal arylethynes, diarylethynes, and a few new arylpyridylethynes with donor substituents have been synthesized in very good yields. Comparative control experiments suggest that the homocoupling yield is determined by concentration of both catalyst and oxygen.
- Elangovan, Arumugasamy,Wang, Yu-Hsiang,Ho, Tong-Ing
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p. 1841 - 1844
(2007/10/03)
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