In the last few articles, we talked about the key electrophilic aromatic substitution reactions and the synthetic strategies based on the ortho, meta, para directing effects. Below is a summary of electrophilic aromatic substitution practice problems from different topics. … Read more
In the previous post, we talked about the nucleophilic aromatic substitution, looking at the specifics of the mechanism, regiochemistry, and the limitations. Below are some additional examples to practice these concepts.
We have seen that most reactions of aromatic compounds involve electrophilic substitutions because the π electrons make the aromatic ring electron-rich and therefore, nucleophilic. However, some aryl halides with a strong electron-withdrawing substituent(s) on the ring can undergo nucleophilic substitution … Read more
The benzylic position is quite reactive and presents a useful synthetic tool for preparing many aromatic compounds. The reason for this reactivity is the resonance stabilization of the benzylic carbon, regardless of whether the reaction goes through an ionic or … Read more
We have already talked about the ortho, para, and meta directions in electrophilic aromatic substitution and their combined effect for disubstituted benzene. This should allow us to synthesize different aromatic compounds starting from benzene. For example, how can we synthesize … Read more
In the previous post, we saw that a benzene ring with an activator undergoes electrophilic aromatic substitution at the ortho and para positions, while deactivated aromatic rings react at the meta position: Here is an interesting question: Where … Read more
Halogens are ortho, para directors, however, they are also deactivators! Here is short summary to answer why halogens, being deactivators, are still ortho, para directors: Now, let’s discuss this a bit more in detail by first doing a … Read more
Aryl diazonium salts can be used as an alternative to the standard electrophilic aromatic substitution reactions for preparing aromatic compounds as well as for synthesizing compounds that cannot be prepared directly from benzene. Before going into the details, here is the summary … Read more
In the previous post, we talked about the orientation effects in EAS when there is more than one substituent on the benzene ring. In short, to predict the substitution site, you need to determine the stronger activator. Using … Read more
In this article, we will discuss the main limitations and undesired pathways in electrophilic aromatic substitution reactions and the strategies to overcome them. Friedel-Crafts Reactions The Friedel-Crafts reactions are used for alkylation and acylation of aromatic compounds. Rearrangement … Read more
