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Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
Aryl azides formation under mild conditions: a kinetic study in some ionic liquid solutions
Francesca D'Anna1, Salvatore Marullo, Renato Noto
1Dipartimento di Chimica Organica E. Paternò, Università degli Studi di Palermo, Viale delle Scienze-Parco d'Orleans II, 90128 Palermo, Italy. fdanna@unipa.it
The Journal of Organic Chemistry
|December 31, 2009
Summary
Nucleophilic aromatic substitution reactions occurred faster in DMF than in ionic liquid solutions. This study investigated nitrothiophene kinetics in various ionic liquid mixtures and DMF, revealing solvent-dependent reaction rates.
Area of Science:
- Organic Chemistry
- Physical Chemistry
- Materials Science
Background:
- Nucleophilic aromatic substitution (SNAr) is a fundamental organic reaction.
- Ionic liquids (ILs) offer tunable solvent properties for chemical reactions.
- Understanding solvent effects on reaction kinetics is crucial for process optimization.
Purpose of the Study:
- To investigate the kinetics of SNAr reactions involving nitrothiophene derivatives.
- To compare reaction rates in various ionic liquid binary mixtures and conventional solvents (DMF).
- To explore the influence of IL cation and anion structure on reaction kinetics.
Main Methods:
- Spectrophotometric analysis at 298 K.
- Study of three nitrothiophene derivatives.
- Use of ionic liquids with varying cation (imidazolium, pyrrolidinium) and anion ([BF4]-, [PF6]-, [SbF6]-, [NTf2]-) structures.
- Comparison with reactions in Dimethylformamide (DMF) with varying azide nucleophile concentrations.
Main Results:
- Reactions proceeded faster in DMF compared to ionic liquid solutions.
- A linear relationship was observed between pseudo-first-order rate constants and nucleophile concentration across all solvent media.
- The choice of ionic liquid cation and anion structure influenced reaction kinetics.
Conclusions:
- Ionic liquids exhibit unique solvent effects on SNAr reaction kinetics.
- The three-dimensional organization of ionic liquids plays a role in their influence on reaction mechanisms.
- Solvent selection significantly impacts the efficiency of nucleophilic aromatic substitution reactions.
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