- Highly efficient stabilisation of meta-ethynylpyridine polymers with amide side chains in water by coordination of rare-earth metals
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An amphiphilic meta-ethynylpyridine polymer with chiral amide side chains was developed. The polymer was prepared by sequential Sonogashira reactions, and the product was soluble in polar and apolar solvents. The additive effects of metal salts on the polymer were examined in water and aqueous EtOH on the basis of UV-vis and CD spectra. The enhancement of the positive Cotton effect and hypochromism around 360 nm occurred by the addition of various metal salts, indicating the coordination of the cations to the amide side chains of the polymer to stabilise the helical structure. Among them, rare-earth metal salts, especially Sc(OTf)3 showed more efficient additive effects probably because of its strong coordination ability even in water. Positive cooperativity was observed for the coordination of Sc(OTf)3 to the polymer in aqueous EtOH.
- Makida, Hiroki,Abe, Hajime,Inouye, Masahiko
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Read Online
- Synthesis of bisfunctionalized-oligopyridines bearing an ester group
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The synthesis of 2,2′-bipyridine, 1,10-phenantroline and 2,2′:6′,2″-terpyridine substituted by an ethylester function is described. The 5- and 6-methyl-2,2′-bipyridines bearing an ethylester group on the 6′ position as well as the ethyl 6,6″-dimethyl-2,2′:6′,2″-terpyridine-4′- carboxylate moiety were synthesized via a Stille cross-coupling reaction, starting from bromo-picoline building blocks. A radical bromination of the methyl-oligopyridine gave selectively the corresponding benzylic bromide derivatives in fair yield.
- Ulrich, Gilles,Bedel, Sébastien,Picard, Claude,Tisnès, Pierre
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Read Online
- The influence of alkyl chains on the performance of DSCs employing iron(ii) N-heterocyclic carbene sensitizers
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The photovoltaic performances of DSCs employing two new iron(ii) N-heterocyclic carbene (NHC) sensitizers are presented. The presence of n-butyl side chains had a significant impact on DSC performace. The improvement in DSC performance up to 0.93-0.95% was observed for a new heteroleptic sensitizer bearing one carboxylic acid anchoring group. The photovoltaic performance was remarkably affected by sensitization time and by a presence/absence of coadsorbent on the semiconductor surface. The highest photoconversion efficiencies (PCE) were achieved for DSCs sensitized over 17.5 hours without addition of coadsorbents. However, for a shorter dipping time of 4 hours, the presence of chenodeoxycholic acid improved the PCE from 0.46% (no coadsorbents) to 0.74%, respectively. The performance of DSCs based on a new homoleptic complex bearing two n-butyl side chains and a carboxylic acid anchor on each NHC-ligand was improved from 0.05 to 0.29% via changes in dye-bath concentration and sensitization time. The changes in the dye load on the semiconductor surface depending on the sensitization conditions were confirmed using solid-state UV-Vis spectroscopy and thermogravimetric analysis. Electrochemical impedance spectroscopy was used to gain information about the processes occurring at the different interfaces in the DSCs. The impedance response was strongly affected by the immersion time of the photoanodes in the dye-bath solutions. In the case of the homoleptic iron(ii) complex, a Gerischer impedance was observed after 17.5 hours immersion. Shorter dipping times resulted in a decrease in the resistance in the system. For the heteroleptic complex, values of the chemical capacitance and electron lifetime were affected by the immersion time. However, the diffusion length was independent of sensitization conditions. This journal is
- Becker, Mariia,Constable, Edwin C.,Housecroft, Catherine E.,Wyss, Vanessa
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supporting information
p. 16961 - 16969
(2021/12/10)
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- Protein-Induced Change in Ligand Protonation during Trypsin and Thrombin Binding: Hint on Differences in Selectivity Determinants of Both Proteins?
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Trypsin and thrombin, structurally similar serine proteases, recognize different substrates; thrombin cleaves after Arg, whereas trypsin cleaves after Lys/Arg. Both recognize basic substrate headgroups via Asp189 at the bottom of the S1 pocket. By crystal
- Ngo, Khang,Collins-Kautz, Chelsey,Gerstenecker, Stefan,Wagner, Bj?rn,Heine, Andreas,Klebe, Gerhard
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p. 3274 - 3289
(2020/04/17)
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- Discovery of dap-3 polymyxin analogues for the treatment of multidrug-resistant gram-negative nosocomial infections
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We report novel polymyxin analogues with improved antibacterial in vitro potency against polymyxin resistant recent clinical isolates of Acinetobacter baumannii and Pseudomonas aeruginosa. In addition, a human renal cell in vitro assay (hRPTEC) was used to inform structure-toxicity relationships and further differentiate analogues. Replacement of the Dab-3 residue with a Dap-3 in combination with a relatively polar 6-oxo-1-phenyl-1,6-dihydropyridine-3- carbonyl side chain as a fatty acyl replacement yielded analogue 5x, which demonstrated an improved in vitro antimicrobial and renal cytotoxicity profiles relative to polymyxin B (PMB). However, in vivo PK/PD comparison of 5x and PMB in a murine neutropenic thigh model against P. aeruginosa strains with matched MICs showed that 5x was inferior to PMB in vivo, suggesting a lack of improved therapeutic index in spite of apparent in vitro advantages.
- Magee, Thomas V.,Brown, Matthew F.,Starr, Jeremy T.,Ackley, David C.,Abramite, Joseph A.,Aubrecht, Jiri,Butler, Andrew,Crandon, Jared L.,Dib-Hajj, Fadia,Flanagan, Mark E.,Granskog, Karl,Hardink, Joel R.,Huband, Michael D.,Irvine, Rebecca,Kuhn, Michael,Leach, Karen L.,Li, Bryan,Lin, Jian,Luke, David R.,Macvane, Shawn H.,Miller, Alita A.,McCurdy, Sandra,McKim, James M.,Nicolau, David P.,Nguyen, Thuy-Trinh,Noe, Mark C.,O'Donnell, John P.,Seibel, Scott B.,Shen, Yue,Stepan, Antonia F.,Tomaras, Andrew P.,Wilga, Paul C.,Zhang, Li,Xu, Jinfeng,Chen, Jinshan Michael
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p. 5079 - 5093
(2013/07/26)
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- BICYCLIC INHIBITORS OF ALK
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The present invention relates to compounds of formula (1) or pharmaceutical acceptable salts, wherein R1, X, Y, Z, A, B, G1, and n are defined in the description. The present invention relates also to compositions containing said compounds which are useful for inhibiting kinases such as ALK and methods of treating diseases such as cancer.
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Page/Page column 69-70
(2012/08/07)
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- BICYCLIC INHIBITORS OF ANAPHASTIC LYMPHOMA KINASE
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Disclosed are compounds of formula (Ⅰ) and their pharmaceutical acceptable salts, wherein R1, R2, R3, X, Y, Z, A, B, G1, m and n are defined in the description. The compositions containing the said compounds used for inhibiting kinases such as anaphastic lymphoma kinase (ALK) and methods of treating diseases such as cancer are disclosed.
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Page/Page column 143
(2012/08/07)
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- Azacrown-attached meta-ethynylpyridine polymer: Saccharide recognition regulated by supramolecular device
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Polymeric synthetic host 2, azacrown-attached 2,6-pyridylene ethynylene polymer, was investigated for its saccharide recognition and the additive effect of triethylene tetramine-trifluoroacetic acid; heteroallosteric effects were observed on the basis of CD and UV/Vis analyses, which indicated saccharide-dependent stabilization and destabilization of helical complexes by the formation of pseudopolyrotaxanes.
- Abe, Hajime,Takashima, Shunsuke,Yamamoto, Tsuyoshi,Inouye, Masahiko
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supporting information; experimental part
p. 2121 - 2123
(2009/09/05)
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- Synthesis of 2,6-di(pyrazol-1-yl)-4-bromomethylpyridine, and its conversion to other 2,6-di(pyrazol-1-yl)pyridines substituted at the pyridine ring
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Two routes to 2,6-di(pyrazol-1-yl)-4-hydroxymethylpyridine (1) from 2,6-dihydroxy-isonicotinic acid, in four and six steps, are reported. Reaction of 1 with 48% HBr yields 2,6-di(pyrazol-1-yl)-4-bromomethylpyridine (2), which is a powerful precursor to a range of new tridentate ligands for transition metals functionalised at the pyridine ring. As a proof of principle, we describe the further elaboration of 2 to give two 2,6-di(pyrazol-1-yl)pyridines bearing nucleobase substituents, and the back-to-back ligand 1,2-bis[2,6-di(pyrazol-1-yl)pyrid-4-yl]ethane. Crystal structures of two of these new derivatives are presented.
- Elha?k, Jér?me,Pask, Christopher M.,Kilner, Colin A.,Halcrow, Malcolm A.
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p. 291 - 298
(2007/10/03)
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- 6,6′-dibromo-4,4′-di(hexoxymethyl)-2,2′-bipyridine: A new solubilizing building block for macromolecular and supramolecular applications
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Although brominated bipyridines and terpyridines are highly desirable synthetic building blocks for both ligand design and macro- or supramolecular applications, few such synthetic precursors have been reported that include much-needed solubilizing groups. Reported here is an inexpensive route to 2,6-dibromo-4-(hexoxymethyl)pyridine from citrazinic acid with an overall yield of 44% and its efficient conversion (60%) to 6,6′-dibromo-4,4′- di(hexoxymethyl)-2,2′-bipyridine via oxidative coupling.
- Amb, Chad M.,Rasmussen, Seth C.
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p. 4696 - 4699
(2007/10/03)
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- Synthesis of heteroarenes using cascade radical cyclisation via iminyl radicals
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Cascade radical cyclisation involving homolytic aromatic substitution has been used to synthesise new tetracycles. Treatment of vinyl iodide radical precursors with Me3Sn radicals (from hexamethylditin) yielded intermediate vinyl radicals which
- Bowman, W. Russell,Cloonan, Martin O.,Fletcher, Anthony J.,Stein, Tobias
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p. 1460 - 1467
(2007/10/03)
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- 2-PYRIDINYL[7-(SUBSTITUTED-PYRIDIN-4-YL) PYRAZOLO[1,5-A]PYRIMIDIN-3-YL]METHANONES
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The present invention provides novel 2-pyridinyl[7(pyridin-4-yl)pyrazolo[1,5--a]pyrimidin-3-yl]methanones with at least one substituent on the 4-pyridinyl ring having the chemical structure of formula (I): The invention further provides compositions and methods employing the novel 2-pyridinyl[7-(pyridin-4-yl)pyrazolo[1,5-a]pyrimidin-3-yl]methanones of formula: (I) in to modulate GABA and GABA receptor physiology to elicit therapeutic responses in mammalian subjects to alleviate neurological or psychiatric disorders, including stroke, head trauma, epilepsy, pain, migraine, mood disorders, anxiety, post traumatic stress disorder, obsessive compulsive disorders, mania, bipolar disorders, schizophrenia, seizures, convulsions, tinnitus, neurodegenerative disorders including Alzheimer's disease, amyotrophic lateral sclerosis and Parkinson's disease, Huntington's chorea, depression, bipolar disorders, mania, trigeminal and other neuralgia, neuropathic pain, hypertension, cerebral ischemia, cardiac arrhythmia, myotonia, substance abuse, myoclonus, essential tremor, dyskinesia and other movement disorders, neonatal cerebral hemorrhage, and spasticity, as well as other psychiatric and neurological disorders mediated by GABA and/or GABA receptors.
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- Carboxylate derivatives of oligopyridines
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The key compound ethyl 2,6-dibromopyridine-4-carboxylate was prepared in two steps starting from the commercially available citrazinic acid. By using the Stille coupling reaction ethyl 2,6- dibromopyridine-4-carboxylate was converted to 2,2'-bipyridines, 2,2':6',2''-terpyridines and 2,2':6',2'':6'',2''':6''',2''''- quinquepyridines which bear a carboxylate functional group directly attached to the central pyridine ring.
- Fallahpour, Reza-Ali
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p. 1138 - 1142
(2007/10/03)
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- Continuous process for the production of polybromopyridine compounds
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A continuous process for producing a polybromopyridine compound comprises admixing a polychloropyridine compound with an anhydrous water soluble solvent in a first reaction zone to form a solution of the polychloropyridine compound. Hydrogen bromide gas is introduced into the solution while maintaining the temperature in the range of from about 70° to about 140° C. to produce a solution of the polybromopyridine compound. The solution is cooled to a temperature in the range of from about 5° to about 35° C. to precipitate the polybromopyridine compound from the anhydrous solvent. The polybromopyridine compound is separated from the anhydrous solvent and the anhydrous solvent is returned to the first reaction zone. Polybromopyridine compounds of increased purity are produced in a process having reduced material, energy and operating costs. The process does not require the use of water or other co-solvents nor the distillation of the reaction product mixture.
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