Electrophilic aromatic substitution
| Autor: | Mireille Grosjean, Jacques Nasielski, Michel M. Jauquet, Ouri Buchman |
|---|---|
| Rok vydání: | 1969 |
| Předmět: |
Organic Chemistry
Inorganic chemistry Lithium acetate Electrophilic aromatic substitution Biochemistry Medicinal chemistry Catalysis Inorganic Chemistry chemistry.chemical_compound Acetic acid chemistry Electrophile Kinetic isotope effect Materials Chemistry Lithium chloride Physical and Theoretical Chemistry Hydrogen chloride |
| Zdroj: | Journal of Organometallic Chemistry. 19:353-357 |
| ISSN: | 0022-328X |
| DOI: | 10.1016/s0022-328x(00)85306-1 |
| Popis: | The rates of the acetolysis of substituted phenyltrimethyltins follow a p σ+ correlation with ϱ = −2.24. Lithium chloride strongly accelerates the destannylation, but this catalysis is depressed if lithium acetate is also present. The rate enhancement caused by lithium chloride can be attributed to the formation of small amounts of hydrogen chloride, which is a much stronger electrophile than acctic acid itself. The equilibrium constant for this process is [HCl] [AcOLi]/[LiCl] = 2.5x10−6 mole/l. The acetolysis shows a solvent isotope effect k(AcOH)/k(AcOD) of 10. The experimental facts are in agreement with a transition state which is rather different from a localised intermediate, and it is suggested that the σ-complex is a very poor approximation to the true transition state in electrophilic aromatic destannylations. |
| Databáze: | OpenAIRE |
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