- Pd/C-Catalyzed Carbonylative Esterification of Aryl Halides with Alcohols by Using Oxiranes as CO Sources
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A carbonylative esterification reaction between aryl bromides and alcohols, promoted by Pd/C and NaF in the presence of oxiranes, has been developed. In this process, oxiranes serve as sources of carbon monoxide by their conversion to aldehydes through a palladium-promoted Meinwald rearrangement pathway. Intramolecular versions of this process serve as methods for the synthesis of lactones and phthalimides. CO gas free! A carbonylative esterification reaction between aryl bromides and alcohols, promoted by Pd/C and NaF in the presence of oxiranes, has been developed. In this process, oxiranes serve as sources of carbon monoxide by their conversion to aldehydes through a palladium-promoted Meinwald rearrangement pathway (see scheme).
- Min, Byul-Hana,Kim, Dong-Su,Park, Hyo-Soon,Jun, Chul-Ho
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supporting information
p. 6234 - 6238
(2016/05/02)
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- Dipole architecture of molecules and mesomorphic behavior of liquid crystals with rigid T-shaped mesogenic fragment
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A number of liquid crystalline polyesters having a rigid T-shaped mesogenic fragment and differing in dipole architecture were synthesized and examined by polarizing optical microscopy, differential scanning calorimetry, and IR and 1H NMR spectroscopy. The thermal stability of the mesophase in the given series of compounds was shown to increase with extension of arms in the T-shaped mesogenic fragment, as well as on replacement of the terminal ester groups (COOAlk) therein by ether moieties (OAlk). Such replacement also enhances smectogenic properties.
- Zuev
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experimental part
p. 1559 - 1564
(2009/06/28)
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- Inhibition of estrone sulfatase (ES) by alkyl and cycloalkyl ester derivatives of 4-[(aminosulfonyl)oxy] benzoic acid
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In our search for potent inhibitors of the enzyme estrone sulfatase (ES), we have undertaken the synthesis and biochemical evaluation of a range of esters of 4-[(aminosulfonyl)oxy] benzoic acid. The results of the study show that the synthesised compounds possess potent inhibitory activity, indeed the cyclooctyl derivative was found to be more potent than 667-COUMATE, which is currently undergoing clinical trials.
- Patel, Chirag K.,Owen, Caroline P.,Ahmed, Sabbir
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p. 605 - 609
(2007/10/03)
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- Synthesis and biochemical evaluation of some novel benzoic acid based esters as potential inhibitors of oestrone sulphatase
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Oestrone sulphatase is an important target in the fight against hormone-dependent breast cancer. In an effort to investigate the reported definitive pharmacophore for oestrone sulphatase and continue our search for potent inhibitors of this enzyme, we have undertaken extensive synthesis, biochemical evaluation and physicochemical property determination of a range of benzoic acid based esters. Here, we report the initial results of our study into a series of straight chain alkyl esters of 4-sulphonylbenzoic acid. Using these compounds, we have investigated the involvement of two physicochemical properties, namely logP and pKa. The results of this study show that there was a strong correlation between the inhibitory activity and the logP of the parent compound. Within the series of compounds studied, hydrophobicity appears to be a more important factor than pKa in determining the overall inhibitory activity. In a previous report, we showed that pKa plays an important role in stabilizing the phenoxide ion resulting from the hydrolysis of the sulphamate group. Here, we propose that although pKa is an important factor in determining the overall inhibitory activity when a wide range of compounds are considered, both hydrophobicity and pKa need to be considered in the design of potential inhibitors of oestrone sulphatase.
- Owen, Caroline,James, Karen,Sampson, Luther,Ahmed, Sabbir
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- Inhibition of estrone sulfatase (ES) by derivatives of 4-[(aminosulfonyl)oxy] benzoic acid
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In our search for potent inhibitors of the enzyme estrone sulfatase (ES), we have undertaken the synthesis and biochemical evaluation of a range of straight chain alkyl esters of 4-[(aminosulfonyl)oxy] benzoic acid. The results of the study show that the synthesised compounds possess greater inhibitory activity when compared to COUMATE, although they were all found to possess lower inhibitory activity with respect to EMATE. Furthermore, the data suggest a strong correlation between logP and IC50 and therefore adds further support to our previous report where we suggested a link between inhibitory activity and hydrophobicity.
- Ahmed, Sabbir,James, Karen,Owen, Caroline P
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p. 2391 - 2394
(2007/10/03)
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- Two-rings-containing phenyl ester compound and anti-perroelectric liquid crystal composition containing the same
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A two-rings-containing phenyl ester compound of the following general formula (1), wherein R1 is a linear alkyl group having 5 to 12 carbon atoms, R2 is a linear alkyl group having 1 to 15 carbon atoms, X1 and X2 are both hydrogen atoms or one of X1 and X2 is a fluorine atom and the other is a hydrogen atom, Y1 and Y2 are both hydrogen atoms or one of Y1 and Y2 is a fluorine atom and the other is a hydrogen atom, and A1 is a hydrogen atom, -CH3 or -CF3, provided that when A1 is a hydrogen atom or -CH3, p is 0 and that when A1 is -CF3, p is 1 and q is an integer of 5 to 8, and an anti-ferroelectric liquid crystal composition containing at least one of two-rings-containing phenyl ester compounds of the above general formula (1) in claim 1 and either an anti-ferroelectric liquid crystal compound or a mixture of anti-ferroelectric liquid crystal compounds.
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- The Effect of Carbonyl Containing Terminal Chains on Mesomorphic Properties in 4,4'-Disubstituted Phenylbenzoates and Phenylthiobenzoates. 4. Phenylbenzoates Containing A (CH2)nCO2R' Group (n = 0-2) on the Phenolic End
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The effect of a (CH2)nCO2R' group on the mesomorphic properties of the esters where X = alkyl or alkoxy, Y = (CH2)nCO2R'(R' = C7 and C9) and n = 0-2 has been studied by synthesizing these esters and determining their mesomorphic properties by hot-stage polarizing microscopy.The starting phenols were prepared by esterification of 4-hydroxybenzoic, phenylacetic or phenylpropionic acids.Both the benzyl and methoxycarbonyl protecting groups were tried with the latter giving higher yields when n = 0 because of better solubility of the protected acid.No mesophases were observed in the esters when n = 1, nematic and smectic A phases occurred when n = 2 and smectic A and C phases when n = 0.A few 1,4-cyclohexane diesters were also prepared using these phenols.The mesomorphic properties of these esters followed the same trend observed in the phenylbenzoates escept no C phases were observed.Comparisons of the transition temperatures for these esters with those for Y = R' showed that both small increases or decreases were observed for Y = CO2R'.However, the addition of a spacer methylene group (n = 1 and 2) always gave lower temperatures with the amount of lowering being much greater for n = 2 than n = 1.A comparison of transition temperatures for Y = CO2R', OCOR', COR' and OR' indicated that these temperatures were higher when Y = COR' as expected from dipole moment considerations but were lower when Y = CO2R' than when Y = OCOR', the opposite expected from these considerations.This trend was also observed in the cyclohexane diesters.Transition temperatures were always higher for the esters when Y has an oxygen atom adjacent to the benzene ring.Therefore, esters with Y = O(CH2)nCO2R', n = 1 and 2 were also synthesized.The phenols were prepared by alkylation of 4-benzyloxyphenol with the bromo esters followed by hydrogenolysis.However, these esters showed no mesophases except the cyclohexane diester with n = 2.
- Neubert, M. E.,Leung, K.,Jirousek, M. R.,Ezenylimba, M. C.,Sabol-Keast, S.,et al.
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