Related Experiment Video
Updated: Jun 2, 2025
06:44
From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
69.0K
Halogenated Trityl Cations as Easy-to-Access Super Electrophiles
Johanna Schlögl1, Amelie L Brosius1, Ahmet N Toraman1
1Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie - Anorganische Chemie, Fabeckstraße 34/36, 14195, Berlin, Germany.
Angewandte Chemie (International Ed. in English)
|January 16, 2025
Summary
Researchers developed a straightforward synthesis for the perfluorotrityl cation and its halogenated derivatives. These compounds exhibit high reactivity and hydride ion affinities, useful for chemical synthesis.
Area of Science:
- Organic Chemistry
- Fluorine Chemistry
- Synthetic Methodology
Background:
- The perfluorotrityl cation (15F+) is a valuable reagent in organic synthesis.
- Functionalization of perfluorinated compounds can lead to novel reactive intermediates.
Purpose of the Study:
- To develop an accessible synthesis of the perfluorotrityl cation.
- To functionalize the para-fluorine atoms of 15F+ via halodefluorination.
- To evaluate the reactivity and electronic properties of the new halogenated trityl derivatives.
Main Methods:
- Synthesis of 15F+ using GaCl3.
- Halodefluorination of 15F+ using trimethylsilyl halides (TMSX).
- Characterization by NMR and UV/Vis spectroscopy.
- Computational and experimental evaluation of hydride ion affinities.
Main Results:
- Easy-to-access synthesis of 15F+ achieved.
- Halogenated trityl derivatives (p-3Cl12F+ and p-3Br12F+) synthesized via halodefluorination.
- NMR and UV/Vis spectroscopy confirmed the impact of para-exchange on electronic structure.
- High hydride ion affinities demonstrated for the new synthons.
Conclusions:
- The developed method provides access to novel, reactive halogenated trityl derivatives.
- These compounds are stable at room temperature and exhibit high hydride ion affinities.
- The new synthons are valuable tools for hydride abstraction reactions from alkanes.
More Related Videos
Related Concept Videos
02:46Halogenation of Alkenes
15.3K
Halogenation is the addition of chlorine or bromine across the double bond in an alkene to yield a vicinal dihalide. The reaction occurs in the presence of inert and non-nucleophilic solvents, such as methylene chloride, chloroform, or carbon tetrachloride.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
15.3K
02:28Electrophiles
10.4K
This lesson explains the definition, classification, and characteristic features of an electrophile that are key features of nucleophilic substitution reactions. An analysis of their charge and orbital picture helps understand their reactivity for seeking electrons. Electrophiles can be classified into positive and neutral species. Other classes include free radicals and polar functional groups.
While a positive electrophile, like a proton, reacts due to its vacant, low-energy 1s orbital, the...
While a positive electrophile, like a proton, reacts due to its vacant, low-energy 1s orbital, the...
10.4K
02:38Electrophilic Addition to Alkynes: Halogenation
8.1K
Introduction
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
8.1K
01:15Electrophilic Aromatic Substitution: Chlorination and Bromination of Benzene
7.7K
Chlorination and bromination are important classes of electrophilic aromatic substitutions, where benzene reacts with chlorine or bromine in the presence of a Lewis acid catalyst to give halogenated substitution products. A Lewis acid such as aluminium chloride or ferric chloride catalyzes the chlorination, and ferric bromide catalyzes the bromination reactions. During the bromination of alkenes, bromine polarizes and becomes electrophilic. However, in the bromination of benzene, the bromine...
7.7K
01:11Reactions at the Benzylic Position: Halogenation
2.4K
Benzylic halogenation takes place under conditions that favor radical reactions such as heat, light, or a free radical initiator like peroxide.
2.4K
01:24ortho–para-Directing Deactivators: Halogens
5.3K
Halogens are ortho–para directors. They are more electronegative than carbon. Therefore, as ring substituents, they can withdraw electrons through the inductive effect and deactivate the aromatic ring towards electrophilic substitution. Halogens also have an electron-donating resonance effect on the ring, which influences the orientation of the incoming electrophile. If an electrophile attacks at the ortho or the para position, the halogen donates electrons and stabilizes the intermediate...
5.3K