- NOVEL THYROMIMETICS
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Compounds are provided having the structure of Formula (I): or a pharmaceutically acceptable isomer, racemate, hydrate, solvate, isotope, or salt thereof, wherein A, X1, X2, Q, R1, R2 and n are as defined herein. Such compounds function as thyromimetics and have utility for treating diseases such as neurodegenerative disorders and fibrotic diseases. Pharmaceutical compositions containing such compounds are also provided, as are methods of their use and preparation.
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Page/Page column 155
(2020/09/19)
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- The Electronic Effect of the Phenylazo and t-Butylazo Groups
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Hammett ?p+-values for arylazo and t-butylazo groups have been determined by measurements of the kinetics of solvolysis of the appropriately substituted arylpropan-2-yl chlorides.They have been found to be considerably more positive than expected and differ significantly from earlier estimates based on the rates of electrophilic attack on azobenzene.An interpretation of the discrepancy has been advanced based on the differing orientations of the azo linkage with respect to the aromatic ring in the transition state.The introduction of methyl groups into positions ortho to the phenylazo and t-butylazo substituents causes a change in character from -I, -R to -I, +R.This is true not only for the solvolysis reaction but also for benzoic acid ionisation.
- Byrne, Christopher J.,Happer, Duncan A. R.,Hartshorn, Michael P.,Powell, H. Kipton J.
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p. 1649 - 1654
(2007/10/02)
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- Conformational Dependence of Isotope Effects for Hyperconjugating Methyl Groups. Nonadditivity of NMR Isotope Shifts in Benzylic Ions
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Deuterium substitution in the methyl groups induces long-range downfield shifts in 13C NMR signals of the ortho and para positions of the phenyldimethylcarbenium ion.Similar downfield isotope shifts occur in 19F signals of (p-fluorophenyl)carbenium ions upon deuteration of α-methyl groups.These NMR isotope shifts are analogous to secondary β-deuterium isotope effects on rates and equilibria and arise from hyperconjugative interactions.The effects of substituting entire CD3 groups for CH3 groups are additive, but the effects of deuterium substitution within a methyl group are not additive.The nonadditive behavior is attributed to unequal populations of the possible methyl conformation for partially deuterated methyl groups, so that each C-H(D) bond is not equally involved in hyperconjugation.This interpretation is supported by the observation of an isotope effect on the vicinal 1H-19F coupling constant in the phenylmethylfluorocarbenium ion, PhCFCH3+.
- Forsyth, David A.,Lucas, Peter,Burk, Robert M.
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p. 240 - 245
(2007/10/02)
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