- Synthesis of a [3.3]biphenylophane, and its photophysical and photochemical properties studied by emission and transient absorption measurements
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[3.3](4,4′)Biphenylophane (BPP) is synthesized, and the photophysical and photochemical properties are studied by means of emission and transient absorption measurements. BPP emits excimer fluorescence at 295 and 77 K, and phosphorescence from the locally-excited (LE) triplet state at 77 K. Based on the transient absorption spectra of BPP, it is found that the excimeric triplet state of BPP is produced along with the LE triplet at 295 and 77 K. The triplet excimer of BPP is shown to be formed via intersystem crossing from the singlet excimer state, and concluded to be non-phosphorescent.
- Yamaji, Minoru,Tsukada, Takehiko,Shizuka, Haruo,Nishimura, Jun
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- Aerobic Homocoupling of Arylboronic Acids Catalyzed by Regenerable Pd(II)@MIL-88B-NH2(Cr)
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A fast and operationally simple method for the aerobic homocoupling of arylboronic acids is described. The process is catalyzed by Pd(II) complexes supported on the metal-organic framework MIL-88B-NH2(Cr). The benefits of this approach include the use of a benign oxidant/solvent mixture at room temperature with catalytic amounts of base, easy recovery of the catalyst, and easy isolation of the products. Very high conversions and good yields were achieved for a variety of substrates, and the process was also carried out on a larger scale with the same efficiency. The catalyst was found to suffer deactivation due to progressive reduction and agglomeration of palladium into inactive metal clusters/particles. An innovative procedure for the oxidative redispersion and regeneration of the active Pd(II)@MOF species is presented.
- Valiente, Alejandro,Carrasco, Sergio,Sanz-Marco, Amparo,Tai, Cheuk-Wai,Bermejo Gómez, Antonio,Martín-Matute, Belén
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p. 3933 - 3940
(2019/05/22)
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- Homodimeric bis-quaternary heterocyclic ammonium salts as potent acetyl- and butyrylcholinesterase inhibitors: A systematic investigation of the influence of linker and cationic heads over affinity and selectivity
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A molecular library of quaternary ammonium salts (QASs), mainly composed of symmetrical bis-quaternary heterocyclic bromides exhibiting choline kinase (ChoK) inhibitory activity, were evaluated for their ability to inhibit acetyl- and butyrylcholinesterase (AChE and BChE, respectively). The molecular framework of QASs consisted of two positively charged heteroaromatic (pyridinium or quinolinium) or sterically hindered aliphatic (quinuclidinium) nitrogen rings kept at an appropriate distance by lipophilic rigid or semirigid linkers. Many homodimeric QASs showed AChE and BChE inhibitory potency in the nanomolar range along with a low enzymatic selectivity. Computational studies on AChE, BChE, and ChoK allowed identification of the key molecular determinants for high affinity and selectivity over either one of the three enzymes and guided the design of a hybrid bis-QAS (56) exhibiting the highest AChE affinity (IC50 = 15 nM) and selectivity over BChE and ChoK (SI = 50 and 562, respectively) and a promising pharmacological potential in myasthenia gravis and neuromuscular blockade.
- Conejo-García, Ana,Pisani, Leonardo,Del Carmen Nú?ez, Maria,Catto, Marco,Nicolotti, Orazio,Leonetti, Francesco,Campos, Joaquín M.,Gallo, Miguel A.,Espinosa, Antonio,Carotti, Angelo
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p. 2627 - 2645
(2011/06/21)
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- Synthesis and characterization of novel unnatural bichalcones
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Five bichalcones (5-1 ~ 5-4, 9) were prepared by the reaction of biphenyl-4,4′-dicarbaldehyde (4) and 4,4′-dioxybenzaldehyde (8) with the respective acetophenone analogs via Claisen-Schmidt condensation and were then fully identified by 1H-NMR, 13C-NMR and mass analyses.
- Gurung, Santosh K.,Kim, Soo Bae,Park, Haeil
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p. 1919 - 1926
(2012/01/05)
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- Synthesis and properties of luminophores derived from fluorinated biphenyls
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A procedure was developed for the synthesis of dimethyl 2-fluoro-and 2,2′-difluorobiphenyl-4,4′-dicarboxylates. The latter were converted into fluorinated 4,4′-bis[(E)-2-(1,3-benzoxazol-2-yl)ethenyl]-and 4,4′-bis[5-(4-octyloxyphenyl)-1,3,4-oxadiazol-2-yl]biphenyls which showed strong luminescence in the crystalline state and in solution; their spectral properties were examined.
- Ol'khovik,Pap,Vasilevskii,Galinovskii,Tereshko
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experimental part
p. 1172 - 1179
(2009/09/25)
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- COMPOUNDS
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The present invention relates to compounds of formula (I), or pharmaceutically acceptable salts thereof, wherein X is selected from (II) and (III), Y is selected from SO2NH, CONH, CH=N, CH2NH and CH=CH; R1-5 are each independently selected from H, OH, OR6, CO2H, C02R7, NO2, CN CONR8R9, CONHR10, CO2(CH2)nCO2R11, CO2(CH2)mO(CO)R12, CO2CHR13COR14, CONH(CH2)pCO2R15, CONH(CH2)qO(CO)R16, CONHCHRI7COR18; R6-18 are each independently hydrocarbyl; n, m, p and q are each independently 1, 2, 3 or 4; with the proviso that when X is phenyl, Y is CH=CH, R3 is OH and R1, R4 and R5 are H, R2 is other than COON. Further aspects of the invention relate to the use of such compounds in the preparation of a medicament for the treatment or prevention of transmissible spongiform encephalopathies (TSEs), and pharmaceutical compositions comprising the same.
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Page/Page column 16
(2010/02/14)
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- Synthesis of rigid polyaromatic dialdehydes
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Rigid polyaromatic dialdehydes: biphenyl-4,4′-dialdehyde and its longer analogues have been synthesized in high yields by using the Suzuki-Miyaura cross-coupling reaction. In addition, a novel procedure for a gram-scale preparation of biphenyl-4,4′-dicarbaldehyde from commercially available 4,4′-bis(chloromethyl)biphenyl has been developed.
- Kozakova, Michala,Budesinsky, Milos,Hodacova, Jana
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p. 161 - 167
(2007/10/03)
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- Synthesis of analogues of Congo red and evaluation of their anti-prion activity
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No cure as of yet exists for any of the transmissible spongiform encephalopathies. In this paper, we describe the synthesis of analogues of Congo red and evaluation against a cellular model of infection, the SMB (scrapie mouse brain) persistently infected cell line, for their ability to inhibit the infectivity of the abnormal form of prion protein (PrP-res). The compounds have also been tested for their ability to inhibit the polymerization of PrP C by PrP-res. A number of analogues showed inhibition of PrP-res infectivity at nanomolar concentrations. Several analogues show promise; the most active compound, 2a, inhibits the formation of PrP-res in SMB cells with an EC50 of 25-50 nM.
- Sellarajah, Shane,Lekishvili, Tamuna,Bowring, Claire,Thompsett, Andrew R.,Rudyk, Helene,Birkett, Christopher R.,Brown, David R.,Gilbert, Ian H.
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p. 5515 - 5534
(2007/10/03)
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- Palladium-iminophosphine-catalyzed homocoupling of alkynylstannanes and other organostannanes using allyl acetate or air as an oxidant
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A palladium-iminophosphine complex was found to catalyze the homocoupling reaction of alkynylstannanes using allyl acetate as an oxidant, whereas aryl- and alkenylstannanes were oxidatively homocoupled with air.
- Shirakawa, Eiji,Nakao, Yoshiaki,Murota, Yasubumi,Hiyama, Tamejiro
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p. 132 - 136
(2007/10/03)
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- Electro-organic reactions. Part 50. Quinodimethane chemistry. Part 1. Electrochemical generation and characterisation of p-quinodimethanes
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Quinodimethanes (QDMs) were generated cathodically from 1,4-bis(halogenomethyl)arenes, either by direct or by mediated reduction, and characterised using cyclic voltammetry in the 0.1 to 200 V s-1 range. Formal redox potentials (E°) were determined, including that, at -15°C, for the parent quinodimethane. Redox catalysis with organic mediators proved to be a convenient method for the generation of quinodimethanes from 1,4-bis(chloromethyl)arenes, either for electroanalytical study of the intermediates or for preparative purposes. The quinodimethanes electrogenerated from bis(chloromethyl)arenes in the presence of an organic mediator react to give good yields of poly(p-xylylenes) (PPXs). A copolymer, proposed to be random, is obtained by mediated co-electrolysis of 1,4-bis(chloromethyl)benzenes and 2,5-bis(chloromethyl)-1,4-dimethoxybenzene.
- Szunerits, Sabine,Utley, James H. P.,Nielsen, Merete F.
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p. 669 - 675
(2007/10/03)
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- Homocoupling of Organostannanes Catalyzed by Iminophosphine-Palladium
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An iminophosphine-palladium complex has been successfully utilized as a catalyst for the oxidative homocoupling reaction of organostannanes using air as an oxidant.
- Shirakawa, Eiji,Murota, Yasubumi,Nakao, Yoshiaki,Hiyama, Tamejiro
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p. 1143 - 1144
(2007/10/03)
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- Mesoporous crystalline solid compound of a diphosphonate/phosphite of a tetravalent metal, with a narrow distribution of mesopores
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The present invention discloses a compound comprising a diphosphonate/phosphite of a tetravalent metal: (where M, R, x and y have the meaning given in the description), in the form of a crystalline solid with an alpha-type lamellar structure with a distance between layers of 7.4 to 20? (depending on the dimensions of radical R), a BET surface area of 250 to 400m2 /g, and porosity within the mesopore range, with at least 50% of the pores measuring 20 to 30?. The compound, depending on the radical R used, may or may not have microporosity in the region between layers. Such a diphosphonate/phosphite of a tetravalent metal is obtained by reaction between diphosphonic acid, phosphorous acid and an oxyhalide of a tetravalent metal, in a solvent comprising dimethyl-sulphoxide/water containing hydrofluoric acid.
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- Mesoporous crystalline compound of a tetravalent metal
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The present invention discloses a compound comprising a diphosphonate/phosphite of a tetravalent metal:, , M[(O3P-R-PO3)1-(x+y)(HPO3)2X(O3P-R-PO3H2)2y], , (where M, R, x and y have the meaning given in the description), in the form of a crystalline solid with an alpha-type lamellar structure with a distance between layers of 7.4 to 20? (depending on the dimensions of radical R), a BET surface area of 250 to 400m2/g, and porosity within the mesopore range, with at least 50% of the pores measuring 20 to 30?. The compound, depending on the radical R used, may or may not have microporosity in the region between layers. Such a diphosphonate/phosphite of a tetravalent metal is obtained by reaction between diphosphonic acid, phosphorous acid and an oxyhalide of a tetravalent metal, in a solvent comprising dimethyl-sulphoxide/water containing hydrofluoric acid.
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