One-step arylthiolation of aromatic compounds by disulfide radical cations generated from oxidation of diaryl disulfides with aluminium chloride
| Autor: | Hiroshi Takeuchi, Keisuke Suga |
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| Rok vydání: | 2000 |
| Předmět: | |
| Zdroj: | Journal of the Chemical Society, Perkin Transactions 2. :1803-1808 |
| ISSN: | 1364-5471 1470-1820 |
| Popis: | Reactions of di(phenyl and 4-tolyl) disulfides 1a and 1b with PhX 3a–e (X = H, Me, Et, Ph and Cl) in the presence of AlCl3 at 25 °C give diaryl sulfides 4–6 by aromatic arylthiolation via the disulfide radical cations 2, along with thiophenols 7 formed in the incomplete reactions. Competitive intramolecular reactions of 2a also yield diphenyl sulfide 4a or/and thianthrene 8. However, the reactions of bis(4-chlorophenyl and 4-fluorophenyl) disulfides 1c and 1d selectively lead to the aromatic arylthiolation in high yields. The Hammett ρ = −8.8 at 25 °C for the phenylthiolation in the reactions of 1a is more negative than that (ρ = −7.0 at −30 °C) using SbCl5 instead of AlCl3, and the value ρ = −8.0 for the arylthiolation using 1d is less negative than that using 1a. These and the other mechanistic aspects support the arylthiolations via2. |
| Databáze: | OpenAIRE |
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