Is COOH an activating group?
Common activating groups (not a complete list): Alkyl, NH2, NR2, OH, OCH3, SR. Common deactivating groups (not a complete list): NO2, CF3, CN, halogens, COOH, SO3H. If you think about it, you’ll also see that where you put the group E on the ring will also influence the carbocation.
Why is COOH a deactivating group?
Oxygen due to electronegativity, it will take the pi bonds making carbon electropositive. This will pull the electrons further attached between the carbons and due to this the positive charge on the arenium ion is further increased rendering it less stable. In this way, carboxylic acid acts as deactivating group.
What will be the attacking electrophile in this reaction?
3. What will be the attacking electrophile in this reaction? Explanation: In halogenation of benzene ring halonium ion (Cl+) will attack at benzene ring.
Does benzene react with electrophiles?
Benzene is a planar molecule having delocalized electrons above and below the plane of the ring. As a result, it is highly attractive to electron-deficient species i.e., electrophiles. Therefore, it undergoes electrophilic substitution reactions very easily. Nucleophiles are electron-rich.
What is ring activating group?
Atoms or groups that make the benzene molecule more reactive by increasing the ring’s electron density are called activating groups. Activating groups serve as ortho‐para directors when they are attached to a benzene ring, meaning that they direct an incoming electrophile to the ortho or para positions.
What are ring deactivating groups?
In organic chemistry, a deactivating group is a functional group attached to a benzene molecule that removes electron density from the benzene ring, making electrophilic aromatic substitution reactions slower and more complex relative to benzene.
How does a methyl group activates benzene ring?
Inductively the methyl group releases electron density into the benzene ring. This is because the methyl group, being sp3 hybridized, is less electronegative than the sp2 hybridized aromatic carbon.
Why does benzene resist electrophilic addition?
There are delocalised electrons above and below the plane of the ring. The presence of the delocalised electrons makes benzene particularly stable. Benzene resists addition reactions because that would involve breaking the delocalisation and losing that stability.
What is the electrophilic substitution reaction of benzene?
Electrophilic substitution of benzene is the one where an electrophile substitutes the hydrogen atom of benzene. As the aromaticity of benzene is not disturbed in the reaction, these reactions are highly spontaneous in nature.