Study of aromatic nucleophilic substitution with amines on nitrothiophenes in room-temperature ionic liquids: are the different effects on the behavior of para-like and ortho-like isomers on going from conventional solvents to room-temperature ionic liquids related to solvation effects?
| Autor: | Domenico Spinelli, Francesca D'Anna, Vincenzo Frenna, Renato Noto, Vitalba Pace |
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| Přispěvatelé: | F. D'Anna, V. Frenna, R. Noto, V. Pace, D. Spinelli |
| Rok vydání: | 2006 |
| Předmět: |
Molecular Structure
Chemistry Organic Chemistry Inorganic chemistry Solvation Imidazoles Temperature Ionic Liquids Stereoisomerism Thiophenes Medicinal chemistry Pyrrolidine chemistry.chemical_compound Kinetics Reaction rate constant Solubility Nucleophilic aromatic substitution Morpholine Ionic liquid Borates Nucleophilic substitution Solvents Solvent effects Amines |
| Zdroj: | The Journal of organic chemistry. 71(14) |
| ISSN: | 0022-3263 |
| Popis: | The kinetics of the nucleophilic aromatic substitution of some 2-L-5-nitrothiophenes (para-like isomers) with three different amines (pyrrolidine, piperidine, and morpholine) were studied in three room-temperature ionic liquids ([bmim][BF4], [bmim][PF6], and [bm(2)im][BF4], where bmim = 1-butyl-3-methylimidazolium and bm(2)im = 1-butyl-2,3-dimethylimidazolium). To calculate thermodynamic parameters, a useful instrument to gain information concerning reagent-solvent interactions, the reaction was carried out over the temperature range 293-313 K. The reaction occurs faster in ionic liquids than in conventional solvents (methanol, benzene), a dependence of rate constants on amine concentration similar to that observed in methanol, suggesting a parallel behavior. The above reaction also was studied with 2-bromo-3-nitrothiophene, an ortho-like derivative able to give peculiar intramolecular interactions in the transition state, which are strongly affected by the reaction medium. |
| Databáze: | OpenAIRE |
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