Abstract
The rates of the Bamberger rearrangement of sterically hindered phenylhydroxylamines have been determined in aqueous sulphuric acid solution and the substituent effects (in particular, the steric effects) are discussed. The rate constants for phenylhydroxylamines with 2-substituents (Me, Cl, I) satisfied the Taft equation: log krel = ρ*σ* - δEs with ρ* - 1.93 and δ - 1.16. The result shows that steric hindrance of the substituents, in addition to the electron-donating effect, has an accelerating effect on the rates of the Bamberger rearrangement. The rate constants for 3-substituted 2-methylphenylhydroxylamines were generally greater than those for 5-substituted 2-methylphenylhydroxylamines. The difference was attributed to the ' buttressing effect ' of neighbouring 3-substituents. This is the first example of steric acceleration of the Bamberger rearrangement.
| Original language | English |
|---|---|
| Pages (from-to) | 1596-1598 |
| Number of pages | 3 |
| Journal | Journal of the Chemical Society, Perkin Transactions 2 |
| Issue number | 12 |
| Publication status | Published - 1981 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Chemistry(all)
Cite this
Kinetics and mechanisms of the Bamberger rearrangement. Part 4. Rearrangement of sterically hindered phenylhydroxylamines to 4-aminophenols in aqueous sulphuric acid solution. / Sone, Takaaki; Hamamoto, Kazuhiro; Seiji, Yoshiyuki; Shinkai, Seiji; Manabe, Osamu.
In: Journal of the Chemical Society, Perkin Transactions 2, No. 12, 1981, p. 1596-1598.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Kinetics and mechanisms of the Bamberger rearrangement. Part 4. Rearrangement of sterically hindered phenylhydroxylamines to 4-aminophenols in aqueous sulphuric acid solution
AU - Sone, Takaaki
AU - Hamamoto, Kazuhiro
AU - Seiji, Yoshiyuki
AU - Shinkai, Seiji
AU - Manabe, Osamu
PY - 1981
Y1 - 1981
N2 - The rates of the Bamberger rearrangement of sterically hindered phenylhydroxylamines have been determined in aqueous sulphuric acid solution and the substituent effects (in particular, the steric effects) are discussed. The rate constants for phenylhydroxylamines with 2-substituents (Me, Cl, I) satisfied the Taft equation: log krel = ρ*σ* - δEs with ρ* - 1.93 and δ - 1.16. The result shows that steric hindrance of the substituents, in addition to the electron-donating effect, has an accelerating effect on the rates of the Bamberger rearrangement. The rate constants for 3-substituted 2-methylphenylhydroxylamines were generally greater than those for 5-substituted 2-methylphenylhydroxylamines. The difference was attributed to the ' buttressing effect ' of neighbouring 3-substituents. This is the first example of steric acceleration of the Bamberger rearrangement.
AB - The rates of the Bamberger rearrangement of sterically hindered phenylhydroxylamines have been determined in aqueous sulphuric acid solution and the substituent effects (in particular, the steric effects) are discussed. The rate constants for phenylhydroxylamines with 2-substituents (Me, Cl, I) satisfied the Taft equation: log krel = ρ*σ* - δEs with ρ* - 1.93 and δ - 1.16. The result shows that steric hindrance of the substituents, in addition to the electron-donating effect, has an accelerating effect on the rates of the Bamberger rearrangement. The rate constants for 3-substituted 2-methylphenylhydroxylamines were generally greater than those for 5-substituted 2-methylphenylhydroxylamines. The difference was attributed to the ' buttressing effect ' of neighbouring 3-substituents. This is the first example of steric acceleration of the Bamberger rearrangement.
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M3 - Article
AN - SCOPUS:37049107699
SP - 1596
EP - 1598
JO - Journal of the Chemical Society, Perkin Transactions 2
JF - Journal of the Chemical Society, Perkin Transactions 2
SN - 1470-1820
IS - 12
ER -