Is Ester activating or deactivating?

[Ocean5]

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Hi everybody,

Is ester actuvating or deactivation, and why?
thanks

 

[Dentalicous1234]

activating.
substituent groups that start with oxygen are activating, that's how I remember it anyways. I think it's because it can donate electrons to the ring.

also remember these groups are not as acidic as electron deactivating groups


hope this helps! 🙂

 

[Ocean5]

activating.
substituent groups that start with oxygen are activating, that's how I remember it anyways. I think it's because it can donate electrons to the ring.

also remember these groups are not as acidic as electron deactivating groups


hope this helps! 🙂

My confusion is that why keton is deactivating but ester is activating? SO what about ROR ( ether)? based on what you are saying ether is activating? right?

 

[cuttiedentist]

if the oxygen of ester is bonded ro ring it is activating. but if the carbonyl carbon is bonded, it is deactivationg
correct me if im wrong

 

[student1985]

An Ester--and all carboxylic acid derivatives for that matter--are deactivating. You can see this becasue the carbonyl carbon on the ester has a partial positive charge due to its polarity difference with the double bounded oxygen. Therefore, it will take electron density away from the ring and is thus deactivating. Check out the picture I drew for clarification: 👍

 

[Ocean5]

Guys!!

I'm gald that I posted this, bc I have taken notes from some where (unfortunately I'm not sure about my source, but it should be one of these famous books) that ESTER and AMIDES are ACTIVATING
CABOXYLIC ACID, KETONE, ALDEHYDE are DEACTIVATING.

I just memorized it just as foggy it was, then I thought I should post this , b/c seems fishy, and now seeing different answers I'm confused more than ever.
CAn some one come up with a valid source and write down what is going on?

ANd especially the thing that one of you said about the Oxygen being the first element or not, well I 've never heard of that. SO please clarify it more. What do you mean that if ester's o2 is bonded it is activation otherwise deactivationg? can you give an example? thank you

 

[student1985]

Guys!!

I'm gald that I posted this, bc I have taken notes from some where (unfortunately I'm not sure about my source, but it should be one of these famous books) that ESTER and AMIDES are ACTIVATING
CABOXYLIC ACID, KETONE, ALDEHYDE are DEACTIVATING.

I just memorized it just as foggy it was, then I thought I should post this , b/c seems fishy, and now seeing different answers I'm confused more than ever.
CAn some one come up with a valid source and write down what is going on?

ANd especially the thing that one of you said about the Oxygen being the first element or not, well I 've never heard of that. SO please clarify it more. What do you mean that if ester's o2 is bonded it is activation otherwise deactivationg? can you give an example? thank you

Here is a valid source (It's from Michigan State University's Chem website):

http://www.cem.msu.edu/~reusch/VirtualText/benzrx1.htm

If you scroll down about half-way, you will see a list of Activating and Deactivating substituents. It clearly shows that ester (CO2R) is a DEACTIVATING group.

As for the whole thing about oxygen being the first element, you have to look at the substiutent attached to the ring. For instance, all of these elements will have oxygen directly attached to the ring:

–OH
–OR
–OCOCH3

However, these are all ACTIVATING because the oxygen is partially negatively charged due to the polarity difference. This negative charge will donate electron density to the ring, and therefore they are activating.

Again, don't make things more complicated than they have to be:
-If you see that the element directly attached to the Benzene ring is negative (either full or partial negative charge), it will be an ACTIVATING group.
-If you see that the element directly attached to the Benzene ring is positive (either full or partial positive charge), it will be a DECTIVATING group.

 

[Ocean5]

Here is a valid source (It's from Michigan State University's Chem website):

http://www.cem.msu.edu/~reusch/VirtualText/benzrx1.htm

If you scroll down about half-way, you will see a list of Activating and Deactivating substituents. It clearly shows that ester (CO2R) is a DEACTIVATING group.

As for the whole thing about oxygen being the first element, you have to look at the substiutent attached to the ring. For instance, all of these elements will have oxygen directly attached to the ring:

–OH
–OR
–OCOCH3

However, these are all ACTIVATING because the oxygen is partially negatively charged due to the polarity difference. This negative charge will donate electron density to the ring, and therefore they are activating.

Again, don't make things more complicated than they have to be:
-If you see that the element directly attached to the Benzene ring is negative (either full or partial negative charge), it will be an ACTIVATING group.
-If you see that the element directly attached to the Benzene ring is positive (either full or partial positive charge), it will be a DECTIVATING group.

Thank you for your explanations. It is clear now.