Which of the following are true about the use of aluminum chloride in the Friedel-Crafts acylation reaction? Note that there may be more than one correct answer.
Aluminum chloride removes chloride from acetyl chloride to generate a nucleophile that can attack the ring of toluene
aluminum chloride removes chloride from acetyl chloride to generate an electrophile that can attack the ring of toluene
Aluminum chloride removes a proton from toluene and makes it more vulnerable to electrophilic attack.
Aluminum chloride is a strong electrophile that attacks the ring
Aluminum chloride is violently destroyed when hydrochloric acid is added
Aluminum chloride reacts with the acylium ion to form aluminum metal and chlorine gas. This must be done in the fume hood.
https://en.wikipedia.org/wiki/Friedel%E2%80%93Crafts_reaction
To determine which of the statements about the use of aluminum chloride in the Friedel-Crafts acylation reaction are true, let us analyze each option:
1. Aluminum chloride removes chloride from acetyl chloride to generate a nucleophile that can attack the ring of toluene: This statement is FALSE. Aluminum chloride does not generate a nucleophile from acetyl chloride. It acts as a Lewis acid catalyst, facilitating the formation of the acylium ion, which is an electrophile.
2. Aluminum chloride removes chloride from acetyl chloride to generate an electrophile that can attack the ring of toluene: This statement is TRUE. Aluminum chloride does remove the chloride group from acetyl chloride, generating the acylium ion, which is an electrophile capable of attacking the ring of toluene in the Friedel-Crafts acylation reaction.
3. Aluminum chloride removes a proton from toluene and makes it more vulnerable to electrophilic attack: This statement is TRUE. Aluminum chloride acts as a Lewis acid, abstracting a proton from the aromatic system of toluene, creating a more activated, electron-deficient species that is susceptible to electrophilic attack.
4. Aluminum chloride is a strong electrophile that attacks the ring: This statement is FALSE. Aluminum chloride is not the electrophile itself. It facilitates the generation of the acylium ion, which acts as the electrophile in the Friedel-Crafts acylation reaction.
5. Aluminum chloride is violently destroyed when hydrochloric acid is added: This statement is FALSE. Adding hydrochloric acid does not lead to the violent destruction of aluminum chloride. However, it can react with the excess of aluminum chloride to form HCl gas and aluminum chloride complexes.
6. Aluminum chloride reacts with the acylium ion to form aluminum metal and chlorine gas. This must be done in the fume hood: This statement is FALSE. Aluminum chloride does not react with the acylium ion to form aluminum metal and chlorine gas. It primarily serves as a catalyst in the Friedel-Crafts acylation reaction and is not consumed in the process.
In summary, the true statements about the use of aluminum chloride in the Friedel-Crafts acylation reaction are:
- Aluminum chloride removes chloride from acetyl chloride to generate an electrophile that can attack the ring of toluene.
- Aluminum chloride removes a proton from toluene and makes it more vulnerable to electrophilic attack.