To the people who are confused, the 2 nitrogens are NOT chiral centres, in both of the nitrogens the lone paors are delocalised, so they are NOT sp3, but effectively sp2 hybridised ,which is why they are not chiral centres, and the ans should DEFINITELY be 2 chiral centres
I appreciate the effort to help others on RUclips with this material. The world needs more people like you. However, I feel I have the Onus to help clarify for other viewers That Nitrogen is sp2 hybridized, the lone pair of electron are in a unhybridized p-orbital; it would not be considered a chiral center. There are only 2 chiral centers, and 4 total stereoisomers possible for the molecule you have drawn. If people left this video thinking that the Nitrogen with the long pairs was a chiral center: They are going to do very poorly in O-Chem.
I know you put this awhile ago but I appreciate the comment. I was watching this video and pausing to test my ability to identify stereocentres, and I could only find the two as well. I've been going by the idea that a nitrogen can only act as a centre if it's in a ring.
I think having chiral centers and being chiral (optically actice) are two different things. A compound can have chiral centre but still can be achiral (optically inactive). Here Nitrogen is a chiral center but not optically active due to nitrogen or pyramidal inversion.
I thought the N would not participate in the evaluation because it is connected to a sp2 hybridized carbon atom...idk, I am currently practicing with a very similar molecule and the correct answer on it does not include the nitrogen. Im confused
there is ONLY 2 chiral centers, the N does not count as chiral center. the chiral centers are considered those 4 different groups attached ONLY to Carbon
This video was awesome!!!!!! I wasn’t struggling with finding the chiral centers; I was struggling with determining what they were attached to. You broke it down beautifully and I understand now. Thank you!
This is late. That nitrogen is chiral, but due to pyramidal inversion, if you could isolate one enantiomer, it would racemize. Cannot typically be isolated. So most people ignore chiral nitrogens
My Orgo professor taught us heteroatoms can be chiral. Nitrogen can be chiral and change its hybridization. It's just confusing so most curriculums don't teach it. On my last exam I DIDNT indicate nitrogen chirality and lost points lol.
That is because nitrogen with a lone pair shows a phenomenon called pyramidal inversion or umbrella effect. Due to this , the nitrogen though sp³ with four different groups is not considered if one of them is a lone pair
I think this is wrong. I thought that chiral centers are atoms that are connected at least four different atoms or atom groups? Also when google this Penicillin, there are not any other example, where nitrogen is chiral...
I disagree The nitrogen in form of amide which is not basic The lone pair electrons are delocalized away from nitrogen by reasonance So the two N atoms are non chiral at all There's 3 chairal centers of 3 carbon atoms only And you misaked by forgetting to add carboxylic group on the beta lactam ring which is essential for activity
Neutral nitrogens with three substituents are not chiral. Positively charged nitrogens with three subsituents are chiral. Anyways, it does not have 4 bonds with anything. It has three with a lone pair.
appreciate your work to help others.... but your answer is wrong..... this molecule given by you has only 2 chiral centers......... 4 stereoisomers...... N atom of two amide groups are sp2 hybridized as C=N bond has partial double bond character ....... therefore N atoms are not chiral........ this molecule look like penicillin but lacks COOH group..... if you get it you will find 3 chiral centers........
This has got to be one of the worst scientifically inept videos ever! Firstly, the intended Penicillin V structure is incorrect as it lacks a carboxylic acid group at chiral centre C2 on the bicyclic 4-thia-1-azabicyclo[3.2.0]heptane ring. Secondly, a lone pair on an amide nitrogen does not count as a substituent when determining if a centre is chiral. Ring C5 and C5 carbons are chiral, as they are each attached to 4 different groups. That's 3 chiral centres. The ring atoms should have been numbered. Note also, the correct spelling of the word "centre."
GUYS...NITROGEN CANNOT BE CHIRAL CENTER...ONLY CARBON... CHIRAL CENTRE IS DEFINED AS SP3 HYBRIDISED CARBON ATOM👈 (only carbon) WITH FOUR DIFFERENT ATOMS OR GROUPS BONDED TO IT....
In Ammonium ion Nitrogen is chiral... It can be Chiral but in this case there is quantum tunnelling of lone pair changing the hybridization or through the inversion and due to this a racemic mixture is formed and the resultant molecule becomes inactive so the nitrogen can't be considered as the stereocentre... but in some cases it can be chiral...
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To the people who are confused, the 2 nitrogens are NOT chiral centres, in both of the nitrogens the lone paors are delocalised, so they are NOT sp3, but effectively sp2 hybridised ,which is why they are not chiral centres, and the ans should DEFINITELY be 2 chiral centres
I appreciate the effort to help others on RUclips with this material. The world needs more people like you.
However, I feel I have the Onus to help clarify for other viewers
That Nitrogen is sp2 hybridized, the lone pair of electron are in a unhybridized p-orbital; it would not be considered a chiral center.
There are only 2 chiral centers, and 4 total stereoisomers possible for the molecule you have drawn.
If people left this video thinking that the Nitrogen with the long pairs was a chiral center: They are going to do very poorly in O-Chem.
+ProfessorMike Correct, for anyone wanting to read more on this. See here: www.chem.ucla.edu/harding/tutorials/nitrogen_inversion.pdf
I know you put this awhile ago but I appreciate the comment. I was watching this video and pausing to test my ability to identify stereocentres, and I could only find the two as well. I've been going by the idea that a nitrogen can only act as a centre if it's in a ring.
I'm 4 years late but yes!!!! Very good!!!!!!!!
I think having chiral centers and being chiral (optically actice) are two different things.
A compound can have chiral centre but still can be achiral (optically inactive). Here Nitrogen is a chiral center but not optically active due to nitrogen or pyramidal inversion.
so is n never a chiral centre?
I think Nitrogen Is not considered here as a chiral center, as Its lone pair is delocalised due to resonance. This question came in JEE (Main) 2020.
Thanks bro I was searching for that question only 😅.
yes,and also, in whatever circumstances, you can only count Nitrogen atoms as chiral in cyclic groups only and not in carbon chains.
i guess some of us mistaken chiral 'centers' as chiral 'carbon' ?
I'm new to biochemistry, thanks for explaining, your video is very helpful :))
Yeah
Same here
I also assumed chiral carbon instead of chiral center
Yeah, and also i thought that electronepairs dont count as a , like he calls it different thing
I thought the N would not participate in the evaluation because it is connected to a sp2 hybridized carbon atom...idk, I am currently practicing with a very similar molecule and the correct answer on it does not include the nitrogen. Im confused
But The 2 Nitrogens Are In Conjugation.. So They Are Planar Right?..So They Cant Be Considered As Chiral Centre, Right?
there is ONLY 2 chiral centers, the N does not count as chiral center. the chiral centers are considered those 4 different groups attached ONLY to Carbon
I appreciate that you also considered O to be a possibility. I have watched 10 videos so far and none addressed that.
i though it was 4 different groups around a C atom, so why are you counting the Nitrogen part
Same question !!
A Chiral center does not have to be to be attached to a carbon, so he is correct.
@@satyamtripathi7736 a chiral center does not have to be attached to a carbon atom, he is correct.
This video was awesome!!!!!! I wasn’t struggling with finding the chiral centers; I was struggling with determining what they were attached to. You broke it down beautifully and I understand now. Thank you!
apparently, nitrogen is not chiral since I've got my test back and got the question wrong =(
maybi lianna it's correct your teacher is just dumb
Yes bcuse nitrogen lone pair is delocalised
only carbon can be chiral
its just a prank bro
This is late. That nitrogen is chiral, but due to pyramidal inversion, if you could isolate one enantiomer, it would racemize. Cannot typically be isolated. So most people ignore chiral nitrogens
doesn't the nitrogen thing show some kind of inversion or is not relevant to chiral center
Very nice explained
very nice voice. thank you from Nigeria
My Orgo professor taught us heteroatoms can be chiral. Nitrogen can be chiral and change its hybridization. It's just confusing so most curriculums don't teach it. On my last exam I DIDNT indicate nitrogen chirality and lost points lol.
It was very helpful thank you so much. The textbook explains this in terms of mirror images that is no not intuitive
nitrogen can't be chiral
they are called groups not things
this is not penicillin V
the "square thing" is called beta-lactam ring
Thank you so much for this video, getting ready for Chem lecture in 45 min and you just saved my brain! Really appreciate it!🙌🏽
My chemistry teacher said to not count the nitrogen, unless it's a quaternary amine with 4 other groups. I am very confused.
That is because nitrogen with a lone pair shows a phenomenon called pyramidal inversion or umbrella effect. Due to this , the nitrogen though sp³ with four different groups is not considered if one of them is a lone pair
@@rushikeshreddy8044 thank you for the explanation
I think this is wrong. I thought that chiral centers are atoms that are connected at least four different atoms or atom groups? Also when google this Penicillin, there are not any other example, where nitrogen is chiral...
I mean to say the Nitrogen that is connected to the Hydrogen
thank you sir, your videos have helped me a lot.
Thanks a lot ...
Love from India💞💞
Can you tell whether it is R or S for those chiral atoms apart from the top-right carbon in the square just by looking at this structure diagram?
looking for a video like this about half an hour now. thx man
The best teacher ever
I thought Chiral Centers related to Carbons only? My textbook definition: A "carbon" atom surrounded by four different groups ????
Nitrogen is not chiral center because Nitrogon inversion occurs!
Exactly my professor said the same thing
How can we find the no of sterio isomers in same structure
can u explain how many optically active product can be obtained due to the monochlorination of Methyl cyclohexane.
the answer guide in my text says this is incorrect.
I disagree
The nitrogen in form of amide which is not basic
The lone pair electrons are delocalized away from nitrogen by reasonance
So the two N atoms are non chiral at all
There's 3 chairal centers of 3 carbon atoms only
And you misaked by forgetting to add carboxylic group on the beta lactam ring which is essential for activity
How many chiral centre have atropine
Thanks for the helpful video.
It is 5 excluding NH. Because of Umbrella Inversion, NH loses it's chirality whereas, Cyclic N posses chirality.
The nitrogen is not chiral!
It is Chiral because there are 4 different bonds coming off of it.
Neutral nitrogens with three substituents are not chiral. Positively charged nitrogens with three subsituents are chiral. Anyways, it does not have 4 bonds with anything. It has three with a lone pair.
but nitrogen have bulky group that's it's will not inverse in umbrella form, so it is chiral
Thanks to you sir🙏
appreciate your work to help others.... but your answer is wrong..... this molecule given by you has only 2 chiral centers......... 4 stereoisomers...... N atom of two amide groups are sp2 hybridized as C=N bond has partial double bond character ....... therefore N atoms are not chiral........ this molecule look like penicillin but lacks COOH group..... if you get it you will find 3 chiral centers........
how N can be chiral??its not a carbon
Due to resonance the nitrogen is an sp2 trigonal planar and not a tetrahedral. Therefore, not a chiral center
but here it deals with the unusualness of the functional groups
the nitrogens in his compound are sp3
Awesome! Really helped me a lot to revise chiral centre concept......!!! Thank you bro..
Seen once. Shall be seen again. Great vid.
Really good explanation..
Thank you
So does this mean when searching for chiral centres we can dismiss all double bonds?
Yes because with a double bond,the carbon would have 3 groups around it not 4
Thank you for this video, but I don't think Nitrogen is a chiral center.
Thank you for your hard working
But what about quantum tunneling in the nitrogen doesn't that prevent it from inverting therefore stop it from being chiral?
explain
So informative
Very very good thanks for this Video
How many diastereomers can be in this molecule ?
Thank you so much 🌺❤
Thanks a lot.... Really It's so helpful video 📹
Thanks. Very helpful.
I LOVE THE EXCITEMENT IN YOUR VOICE WHILE LOOKING FOR THE CHIRAL CENTERS. 12 OF 10!
The vidio is of 2015 but this help me on 2020
Thank you very much for your explanation
Thanks alot this video has helped alot
Nate your the man.
wrong, both nitrogens are not a chiral centre because there will be resonance between nitrogen and c=o which is atteched at the adjusent position.
excellent explaination sir
How do you know that the Nitrogen has 2 lone pairs instead of 2 hydrogen bonds?
Still valuable knowledge
N ni hoga chiral vo resonance mai hai
Makes so much more sense now, after listening to multiple people explain it and watching a few videos, this makes it clear.
Yes, it helped me lot. Thank you!
video was really helpful
, PS; nitrogen group not chiral
Could anyone name this molecule pleeeeeeeeeeeeease?
penicillin G
Thank you so much sir. It was very helpful.
Can we also call it a stereogenic center?
Yes
this is penicillin V structure missing the COOH
Thank u so much. It was really helpful :)
What if it has A double bond with oXygen and a bond with H and A bond with C
Thanks man, that helped me in Pharmacolgy
This came in my exam
Wow great i pray it comes in my exam too
This has got to be one of the worst scientifically inept videos ever! Firstly, the intended Penicillin V structure is incorrect as it lacks a carboxylic acid group at chiral centre C2 on the bicyclic 4-thia-1-azabicyclo[3.2.0]heptane ring. Secondly, a lone pair on an amide nitrogen does not count as a substituent when determining if a centre is chiral. Ring C5 and C5 carbons are chiral, as they are each attached to 4 different groups. That's 3 chiral centres. The ring atoms should have been numbered. Note also, the correct spelling of the word "centre."
Thank you so much for helping...
Thank you so much!!
This video has helped me a lot..thank you! :)
Thank you!!!
thank you :>
chirality is a character related to only carbon not any other atom
+suzy leon hanna No. Any tetrahedral atom that has bonds with four different atoms can be a chiral centre. Usually it is a carbon.
wrong,there will be any atom chiral centre provided it should be atteched with four different things
Not necessarily
THAAAANKYOUUUUU 💖💖💖
Smart way!
Love from India🇮🇳🇮🇳🇮🇳
now it is esay . thank you
A lone pair of hydrogen and a hydrogen is the same thing so Nitrogen is not chiral
thank you
Tat nitrogen attached to hydrogen is not chiral cuz nitrogen undergoes rapid inversion!
hapo sawa a very good lesson
You sound kinda like Tom Cruise...
thanks it helped a lot
Isn't it asymmetrical
thank you ❤️
i love you Nate, you've helped me understand chirality!!!!!!! THANK YOU SO MUCH
Thanks a lot man!
Thank you
Thank you sir😊
GUYS...NITROGEN CANNOT BE CHIRAL CENTER...ONLY CARBON... CHIRAL CENTRE IS DEFINED AS SP3 HYBRIDISED CARBON ATOM👈 (only carbon) WITH FOUR DIFFERENT ATOMS OR GROUPS BONDED TO IT....
In Ammonium ion Nitrogen is chiral... It can be Chiral but in this case there is quantum tunnelling of lone pair changing the hybridization or through the inversion and due to this a racemic mixture is formed and the resultant molecule becomes inactive so the nitrogen can't be considered as the stereocentre... but in some cases it can be chiral...
Thanks a lot ;)
Thank you 😘😘😘😘. Helped a lot :>>
How do u hang ur camera