The mechanism is similar to the one used for bromination.
There is a mechanism for the aromatic substitution reaction when benzene is treated with a complex.
The same mechanism is used to install a br on the ring.
Don't look back at that mechanism to copy it.
When you are done, compare your answer to the answer in the back of the book to make sure that all of your arrows were drawn correctly.
When treated with a suitable source of I+, aromatic rings will also undergo iodination.
If you are responsible for knowing how to iodinate benzene, you should look in your textbook and lecture notes.
The mechanism is the same as what we have seen.
The mechanism of how I+ is formed will be the only difference.
There is a mechanism for the reaction between benzene and I+.
The mechanism of an aromatic substitution reaction was shown in the previous section.
The mechanism is the same if you are installing I+ on the ring.
This same mechanism explains how an aromatic ring can be used to install an E+).
We need NO+ to form nitrobenzene.
This complex could be a source of NO+.
We need to take a close look at how NO+ is formed.
You can't do that because it would give five bonds to the central nitrogen atom.
Nitrogen can't have five bonds because it only has four orbitals.
Charge separation is needed to draw nitric acid.
It's true that nitric acid and sulfuric acid are acidic.
It might make us uncomfortable to use nitric acid as a base, but that is exactly what is happening.
The acid removes a protons from the acid.
This probably would make more sense.
It is likely to happen a lot more often.
The un charged oxygen atom is more difficult to remove than the negative charged oxygen atom.
The transfers of protons are not always permanent.
All of the time, particles are being transferred back and forth.
The only thing that can happen when the oxygen atom is negatively charged is for the protons to be given back to nitric acid.
The un charged oxygen atom can remove the protons.
NO+ is generated when this happens.
The same mechanism that we saw in the previous section is used once again: NO+ on and then H+ off.
There is plenty of water because nitric and sulfuric acids are both aqueous solutions.
The mechanism is very similar to what we have seen before.
We have seen how to install a halogen on an aromatic ring and a nitro group.
Make sure you are familiar with the reagents needed to perform these reactions before we move on.
In order to achieve the desired transformation, identify the reagents that you would use.
A piece of paper is needed to record your answer.
We will learn how to install an alkyl group.
A methyl group is the simplest of the alkyl groups.
The logic we have developed in this chapter would allow us to use CH+.
It would not be very stable.
We don't use primary or methyl when drawing mechanisms.
We are trying to make a carbocation.
The answer is yes.
We will use the same method that we used in the previous sections.
We are not forming a free carbocation that can float off into solution.
We must see this as a complex that can serve as a source of CH+.
We have seen the same mechanism over and over again.
A Friedel-Crafts alkylation is a process in which an alkyl group is put on an aromatic ring.
It works well for installing groups on the ring.
There is a simple reason for this.
Since we are forming a complex with a carbocationic character, it is1-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-65561-6556 It is not possible to rearrange a carbocation.
An ethyl carbocation cannot be rearranged to become more stable.
A mixture of products is what we observe.
If you use a Friedel-Crafts alkylation to look for carbocations, you need to be careful.
We already know that we will get some rearrangement, and we will not get a good yield of the desired product.
We will likely get a mixture of products if we just use 1-chlorohexane.
We need a trick.
There is a trick.
We need to look at a similar reaction that bears the name Friedel-Crafts to see how it works.
Let's compare an acyl group with an alkyl group.
The first reagent is called an acyl chloride, and we are already familiar with its role.
There is a positive charge.
There are no side products that would result from a carbocation.
Let's point out a very important feature when we take a close look at the acylation above.
We will only focus on one method right now, but we will see two other methods in the future, one using basic conditions and the other using neutral conditions.
In the presence of zinc that has been treated so that its surface is an alloy of zinc and mercury, the C--O bond is completely reduced and replaced with two C--H bonds.
A Friedel-Crafts acylation can be followed up by a Clemmensen reduction, as a clever way of installing an alkyl group on an aromatic ring.
When you want to install an acyl group on the ring, you won't want to do a Clemmensen reduction afterwards.
You would just use Friedel-Crafts acylation to achieve this transformation.
There is no need for a reduction in the bond because we don't want to reduce it.
An alkyl group needs to be installed on a benzene ring.
We want to see if we can do this in one step.
We have to worry about a carbocation because we can't do it in one step.
What reagents would you use to accomplish the transformation?
Friedel-Crafts acylation is used in some situations, while Friedel-Crafts alkylation is used in other situations.
All of the possible rearrangements can be considered.