- Mesogenic Properties of Copper(II) Complexes formed from α-Substituted β-Dialdehydes and β-Diketones
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The relationship between molecular structure and mesogenic properties is explored for copper(II) complexes of α-substituted β-dialdehydes and β-diketones.The copper(II) complex of p-pentylphenylmalonaldehyde shows a nematic phase, but the presence of off-
- Blake, Antony B.,Chipperfield, John R.,Clark, Stephen,Nelson, Peter G.
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- Study on the design, synthesis and structure-activity relationships of new thiosemicarbazone compounds as tyrosinase inhibitors
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52 Structure-based thiosemicarbazone compounds bearing various substituted-lipophilic part, including substituted-benzaldehyde, substituted-phenylalkan-1-one and their biphenyl-type thiosemicarbazone analogs, were designed, synthesized and evaluated as new tyrosinase inhibitors. The results demonstrated that 22 compounds have potent inhibitory activities against tyrosinase with the IC50 value of lower than 1.0 μM. On the basis of the obtained experimental data, the structure-activity relationships (SARs) were rationally derived. Besides, the inhibition mechanism and the inhibitory kinetics of selected compounds 3d and 6e were investigated, revealing that such type of compounds were belonged to the reversible and competitive tyrosinase inhibitors. To verify the safety of these developed thiosemicarbazone compounds, four randomly selected compounds 3d, 4e, 6a and 9a were also tested in 293T cell line for the evaluation of the cytotoxicity. Interestingly, all these compounds almost did not perform any toxicity to 293T cells even at a high concentration of 1000 μmol/L. Taken together, these results suggested that such compounds could serve as the highly efficient and more safe candidates for the treatment of tyrosinase-related disorders.
- Song, Senchuan,You, Ao,Chen, Zhiyong,Zhu, Guoxun,Wen, Huan,Song, Huacan,Yi, Wei
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p. 815 - 825
(2017/09/05)
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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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- Length- and direction-specific solute-solvent interactions as determined from Norrish II reactions of p-alkylalkanophenones in ordered phases of n-butyl stearate
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The photochemistry of a series of p-alkylalkanophenones (1) has been investigated in the ordered and isotropic phases of n-butyl stearate (BS). By varying the total length of the ketones and the relative position of the benzoyl group within ketones of constant length, the solvent-related factors responsible for Norrish II product selectivity and reactivity have been identified. Specifically, the location of the hydroxy 1,4-biradical intermediates from 1 with respect to the carboxyl groups of neighboring BS molecules and the orientation of the biradical centers within a BS layer appear to control the nature and efficiency of product formation. Infrared spectra of models of the hydroxy 1,4-biradicals in BS and eicosane support the hypotheses. Differential scanning calorimetric data indicate that the ketones exhibiting the lowest product selectivity or least reactivity are not incorporated well within the BS anisotropic phases.
- He, Zhiqiang,Weiss, Richard G.
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p. 5535 - 5541
(2007/10/02)
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- Synthesis and Liquid Crystalline Phases of Pyridazine Derivatives II
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Four more pyridazine compounds were synthesized.The compounds have a general structure R-X-Y-Z-R'; where Y is 3,6 disubstituted pyridazine ring, X and Z are either trans cyclohexyl or phenyl rings, R and R' are n-alkyl groups.The structure assignments were confirmed by carbon 13 NMR.Their liquid crystalline properties were evaluated.When both X and Z are cyclohexyl rings, the compounds have a single smectic b phase.However, if a phenyl ring is introduced into the system, the morphology becomes complicated.Keywords: synthesis, pyridazine, smectic, classification
- Liang, Jason C.,Cross, Julie O.
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p. 235 - 244
(2007/10/02)
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- The Synthesis of 3-Aryl-6-alkylpyridazines
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Nine compounds of general structure R-X-Y-R' where X is a para-disubstituted phenyl ring and Y is a 3,6-disubstituted-pyridazine ring were synthesized.These can be used as liquid crystal dopents.A general procedure for their synthesis was developed.N-Alkyl benzene and ethyl butyrylacetate were used as starting materials.The purification of reaction intermediates was not necessary if preparative hplc was used to purify the final products.Very pure materials were obtained with good yield.Their structure was confirmed by carbon 13 nmr.
- Liang, Jason
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p. 1297 - 1299
(2007/10/02)
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- Multiple Melting Behaviour in Square-planar trans-Bis-(1-p-n-alkylphenylbutane-1,3-dionato)copper(II) - The Effect of Alkyl Chain Length
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The title complexes having different n-alkyl groups from methyl to dodecyl have synthesized.All these complexes exhibit solid polymorphism.The number of polymorphs depends on the length of the alkyl chain: two for n (the number of carbon atoms) = 0-2, three for n = 3-5 and 12, and four for n = 6-11, respectively.Each polymorphic form except those with the highest m.p.s. exhibits multiple melting behaviour: double melting for n = 0-5,8, and 12, and triple melting for n = 6-11 except 8.The m.p.s. of the complexes with alkyl groups of odd carbon atoms are higher than those with even atoms, while the respective ligand solids show the opposit e even-odd effect in their m.p.s.
- Ohta, Kazuchika,Jiang, Guang-Jie,Yokoyama, Masaaki,Kusabayashi, Shigekazu,Mikawa, Hiroshi
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p. 283 - 294
(2007/10/02)
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- Study of the Influence of Molecular Length on the Characteristics of the Ordered Smectic Phase.
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Study of DTA and X-rays of p-phenyl-benzylidene-p'-alkylanilines of mesomorphic phases demonstrates the predominant role of the aliphatic chain length. In effect, it governs the appearance of the different phases; the correlation between layers decreases for greater chain lengths. The nonlinear variations of SmB layer thickness for these compounds shows clearly the importance of steric effects coupled with the molecular length with respect to the dipolar effect.
- Benattar,Levelut,Strzelecki
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p. 1233 - 1240
(2007/10/05)
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