hi! I don't quite understand why removing a proton from the alpha carbon doesn't work (1:25) - couldn't the electrons just form a lone pair on the carbon?
I think I understand, but need some reconfirmation. Since the base abstracts H from the beta carbon, in that case a methyl halide does not undergo elimination reactions since there's only the alpha Carbon. And primary, secondary, and tertiary halides undergo E1/E2 depending on weak base/strong base, steric hindrance is not a factor
the first part is correct, a methyl halide can't possibly undergo elimination. otherwise elimination can occur and the mechanism will depend essentially just on the strength of the base, and steric hindrance isn't a factor for determining the mechanism, but it is a factor in determining which proton is abstracted (zaitsev/hoffman) products.
What are other conditions for sn1 or e1 to occur other than temperature and ... The steric hinderence of reagent and substrate both responsible for sn1 and e1 .....
merci! je veux savoir si t'as une video qui explique quand utiliser SN1, E1, SN2, E2 rxns? :-D je sais que SN2 et E2 sont rxns competitif... egalement pour SN1 et E1.
i don't really speak french but i think you're asking for a clip that explains when to choose which mechanism? i did that already! find it in my organic chemistry playlist.
Je vois que ce comment etais la depuis 7 moins, mais si ca marche pour vous ou quel-qu'un d'autre il y a une video la ruclips.net/video/IOViLLuDMTs/видео.html
Cool Prof. Dave ... nice and short. Hydroxide ion steals a Hydrogen off beta carbon on Bromopropane molecule , also releasing the Bromine, turning it into Propene. With Water molecule. Thanks. Well done !!
Why is it specific that bulky bases like tertiary butyl alcohol and if Flourine give only Hoffman products? Is it that they give only Hoffman? Or do they also give other minor products??
the bulkier the base the more the hoffman product will be preferred for reasons of kinetics. the activation barrier associated with generating the hoffman product is lower than that associated with zaitsev. but there is typically a mixture, depending on precisely how bulky.
+pk sagara depends on various factors like solvent system, temperature. this is just one mechanism that could happen. in fact, unless otherwise specified, you would certainly get a mixture of SN2 and E2 products.
I'm a little confused. You said that the electrons will have nowhere to go when a proton is removed from the alpha position, but isn't there an electronegative bromine atom it's bonded to that would be perfectly happy to accept those electrons? Why can't this happen?
@@ProfessorDaveExplains Oh, I get it now. The carbon-bromine bond supplies bromine with electrons, so it won't be accepting any more. That took me embarrassingly long to figure out. Thanks!
this might be a dumb question but why does the leaving group (Br) leave the molecule? Like why does it's bond weaken? Isn't the (Br) stronger than the proton?
well it's quite stable in solution on its own, and the collision between the base and the proton was of sufficient energy for the reaction to occur, and for the pi bond to form, the leaving group must leave.
it's just because the transition state is showing all the geometry, before we were simplifying and making it look flat. yep the proton being abstracted by the base is the same as the one that is drawn in before.
check out the VSEPR tutorial in general chemistry, and maybe the first IUPAC tutorial in the organic chemistry playlist as well to make sure you understand line notation
With the transition state you have drawn, does this imply that the antiperiplanar nature of the hydrogen and bromine atoms is the best conformation for an E2 reaction?
Ashwangg in fact, it is the only possible conformation from which E2 can occur, because it is the only way for the developing p orbitals to generate the overlap that will result in the pi bond.
If you are referring to the orientation of the beta proton, that is covered in my tutorial on E2 on cyclic systems. If you actually meant regiochemistry, that is covered in my tutorial on Zaitsev vs. Hofmann elimination products.
sure, polar protic solvents make mechanisms with carbocation intermediates more favorable, they also reverse the nucleophilicity trend of the halides, stuff like that.
Prof. Dave Ji ( In Malayalam Dave = Dev ( The God) . You mechanically acted like God to us guys though. Am from Kerala S. India. Am a Tutor and love to view your videos for finalized notes. Teaching upto plus two. Expecting your valuable videos still. Corona is not a joke. Really creepy when the educational arena is considered. You do rock Sir. Take Care please. Saareeyakal Sir !!! 🙏🙏🙏
@@ProfessorDaveExplains in the video the alpha is attached to the bromine and then the beta is attached to a hydrogen and methyl group so I guess I just don't understand how to identify what is what. Is there a general rule to it?
They're just relative terms, in this case they reference the halogen. Alpha means one away, so the carbon attached to the halogen is alpha to the halogen, and any carbon one further away than the alpha carbon is a beta carbon.
Thank you very much sir Can I ask you a question please? If I have 2-bromobutane in an elimination reaction then what would the product be But-1-en or But-2-en or both? Thanks in advance 🌺🌺
Hi Professor Dave, I'm having trouble doing an E2 reaction when given a molecule in a Fischer projection. My current method is to convert the Fischer projection to a sawhorse, then to a Newman, then finally the final product. However, this process is very tedious and I always end up making mistakes. Is there a better way of doing this starting with a Fischer projection?
Fischers are annoying, huh? I've never done eliminations that way, you definitely don't need Newmans, but the best way to be sure is to convert into line notation and do it that way. Otherwise you can probably do them right on the Fischer, you just have to make sure the stereochemistry works.
+AstridMPerez it certainly could! i'm just outlining the E2 mechanism. to decide which would occur you'd need to know more about solvent, temperature, etc, and if just given these compounds in a general sense, both mechanisms would occur and you'd get a mixture of products.
@@Obamnaz Surah al-Ikhlas [112:1-4] ; Say, “He is God, the One. God, the Absolute. He begets not, nor was He begotten. And there is nothing comparable to Him.” Surah al-Ikhlas [112:1-4] All prophets, from Adam, the first prophet, to Muhammad, the last prophet, were human. The duty of the prophets was to teach people about the existence and unity of the Creator and to show them the right path. The duty of Joseph, Noah, Abraham, Jesus, Moses and Muhammad and all pther Probhets of Allah was to call people to believe in the oneness of Allah. Prophet Jesus was a human being like other prophets, he ate, slept, walked on earth, how do you qualify a human as God? How would you characterize the Creator, who created and rules the entire universe, all living things, and the entire universe, as human? Creator is eternal. He doesn't need to eat, drink or sleep like us humans. He does need anything. He does not eat, drink, sleep. It is free from all deficiencies and shortcomings. He is one. He is all-knowing, all-seeing.
@@Obamnaz “O People of the Scripture, do not commit excess in your religion or say about Allah except the truth. The Messiah, Jesus the son of Mary, was but a messenger of Allah and His word which He directed to Mary and a soul [created at a command] from Him. So believe in Allah and His messengers. And do not say, "Three"; desist - it is better for you. Indeed, Allah is but one God. Exalted is He above having a son. To Him belongs whatever is in the heavens and whatever is on the earth. And sufficient is Allah as Disposer of affairs.” Surah An-Nisa 171.verse [4:171] And [beware the Day] when Allah will say, "O Jesus, Son of Mary, did you say to the people, 'Take me and my mother as deities besides Allah ?'" He will say, "Exalted are You! It was not for me to say that to which I have no right. If I had said it, You would have known it. You know what is within myself, and I do not know what is within Yourself. Indeed, it is You who is Knower of the unseen. I said not to them except what You commanded me - to worship Allah , my Lord and your Lord. And I was a witness over them as long as I was among them; but when You took me up, You were the Observer over them, and You are, over all things, Witness. Surah Maidah [5:116-117] My friend, you are saying a heavy word, I hope you research, read and learn. I hope you hear the call of Jesus and all the other prophets and you will believe that the God, the Creator and Sovereign of the universe is one. There is no God but Allah. Take care of yourself, have a nice day. And you can listen Surah Al-Maidah, there is speech of Jesus PBUH with Allah.
Need OChem help? Find me and all the resources you need on Chemmunity: chemmunity.info/dave
short and sweet. this video does not drag on
never thought of it as hydrogen bonding. Professor Dave is clutch 👏
Tommorrow I have organics exam and iam so afraid.
how did it went?
I feel u brother, my exam in 20 mins
My exam is in 5 minutes and im cooked
In a hour si My exam
You are soooo helpful for my orgo chem class!!!
It is clear but short
Another great video....your intro is priceless!
hi! I don't quite understand why removing a proton from the alpha carbon doesn't work (1:25) - couldn't the electrons just form a lone pair on the carbon?
Carbanions are very unstable!
Professor Dave u r the best!! U saved my life thanks so much!!
Professor Dave I would like to talk to you about a lot of things!!!! lol
+Attia Morrison i'm always down to chat! feel free to email me.
Smooth.
@@ProfessorDaveExplains what the different between strong Nucleophilic and strong base
There is lots of overlap, but a good nucleophile will coordinate and a good base will act as a base.
@@ProfessorDaveExplains
Thanks 😀
I think I understand, but need some reconfirmation. Since the base abstracts H from the beta carbon, in that case a methyl halide does not undergo elimination reactions since there's only the alpha Carbon. And primary, secondary, and tertiary halides undergo E1/E2 depending on weak base/strong base, steric hindrance is not a factor
the first part is correct, a methyl halide can't possibly undergo elimination. otherwise elimination can occur and the mechanism will depend essentially just on the strength of the base, and steric hindrance isn't a factor for determining the mechanism, but it is a factor in determining which proton is abstracted (zaitsev/hoffman) products.
Professor Dave Explains ah yes thank you very much
Nice explaination.
What are other conditions for sn1 or e1 to occur other than temperature and ...
The steric hinderence of reagent and substrate both responsible for sn1 and e1 .....
I did not understand where did the CH3 came in the transition state, could you please explain?
Britta Noor it was already there, look closely.
merci! je veux savoir si t'as une video qui explique quand utiliser SN1, E1, SN2, E2 rxns? :-D
je sais que SN2 et E2 sont rxns competitif... egalement pour SN1 et E1.
i don't really speak french but i think you're asking for a clip that explains when to choose which mechanism? i did that already! find it in my organic chemistry playlist.
Je vois que ce comment etais la depuis 7 moins, mais si ca marche pour vous ou quel-qu'un d'autre il y a une video la ruclips.net/video/IOViLLuDMTs/видео.html
chemistry is cool when u finally understand something🎉
Cool Prof. Dave ... nice and short. Hydroxide ion steals a Hydrogen off beta carbon on Bromopropane molecule , also releasing the Bromine, turning it into Propene. With Water molecule. Thanks. Well done !!
What are you doing now brother
What does the inequality sign on the corner of the intermediate bracket represent?
Is this series..(play list of organic chemistry) sufficient for neet!! Plz answer me
hi professor! what's differences between E1 and E2 reaction?
Thank you !!! I finally get it
Why is it specific that bulky bases like tertiary butyl alcohol and if Flourine give only Hoffman products? Is it that they give only Hoffman? Or do they also give other minor products??
the bulkier the base the more the hoffman product will be preferred for reasons of kinetics. the activation barrier associated with generating the hoffman product is lower than that associated with zaitsev. but there is typically a mixture, depending on precisely how bulky.
+Professor Dave Explains Thanks
Could it also happen that an Ether synthesis will happen in this example?
God bless you sir
wouldn't a primary substrate w/ strong base favor sn2?
+pk sagara depends on various factors like solvent system, temperature. this is just one mechanism that could happen. in fact, unless otherwise specified, you would certainly get a mixture of SN2 and E2 products.
pk sagara
I'm a little confused. You said that the electrons will have nowhere to go when a proton is removed from the alpha position, but isn't there an electronegative bromine atom it's bonded to that would be perfectly happy to accept those electrons? Why can't this happen?
there is already a bond between the bromine and the carbon, only a beta proton allows for elimination
@@ProfessorDaveExplains Oh, I get it now. The carbon-bromine bond supplies bromine with electrons, so it won't be accepting any more. That took me embarrassingly long to figure out. Thanks!
this might be a dumb question but why does the leaving group (Br) leave the molecule? Like why does it's bond weaken? Isn't the (Br) stronger than the proton?
well it's quite stable in solution on its own, and the collision between the base and the proton was of sufficient energy for the reaction to occur, and for the pi bond to form, the leaving group must leave.
Professor Dave Explains oh ok thank you very much
Subbed!
sir how to differ between sn2 and e2 mechanism because they both uses nucleophile and
R-x type reactant?
well one does substitution the other does elimination! big difference in product
shouldn't the hydrogen be anti-coplanar to the alpha carbon for elimination reactions?
anticoplanar to the leaving group!
Dr what is the different between strong Nucleophilic and strong base?
And also if we have strong base
The mechanism follow SN1 or SN2
check out my tutorial on "choosing the mechanism" to learn more
@@ProfessorDaveExplains ok thanks
감사합니다 !!
thanks a lot !
HI SIR!!,
I DIDNT UNDERSTAND THE PART U EXPLAINED WHT WILL WILL HAPPEN IF A PROTON IS REMOVED FROM ALPHA CARBON . CAN U EXPLAIN IT PLSSSSSSS
that's part of an elimination reaction. i don't understand, what's the question?
@@ProfessorDaveExplains If you deprotonate at the alpha carbon, why can't those electrons go form the double bond between the alpha and beta carbons?
thanks
Are there any orbitals we should be concerned about in this reaction?
just the p orbitals that will for the pi bond, check out the next one about E2 on cyclic systems to see how the H and LG must antiperiplanar
@@ProfessorDaveExplains thank you!
why does the transition state look so different? Is that H on the bottom left the same one thats on the top attached to the beta carbon before?
it's just because the transition state is showing all the geometry, before we were simplifying and making it look flat. yep the proton being abstracted by the base is the same as the one that is drawn in before.
any video you would recommend to understand the geometry because i have no idea whats going on there
check out the VSEPR tutorial in general chemistry, and maybe the first IUPAC tutorial in the organic chemistry playlist as well to make sure you understand line notation
But I would like to have an example with easy equation because am not understanding those lines
Sir is Bromide anion stable , if it's not how this reaction can takes place ?
yes it's very stable!
With the transition state you have drawn, does this imply that the antiperiplanar nature of the hydrogen and bromine atoms is the best conformation for an E2 reaction?
Ashwangg in fact, it is the only possible conformation from which E2 can occur, because it is the only way for the developing p orbitals to generate the overlap that will result in the pi bond.
How can we distinguish polar protic solvents from other solvents
polar protic solvents, like water, have polar bonds, and protons available for hydrogen bonding and potentially proton transfer.
Thanks
Good
Professor Dave, what does the symbol outside of the transition state bracket mean? (the one that looks like a caravaca cross)
it just means transition state
this nigga saving my life
Should have talked about stereochemistry for.this reaction, IMO, even if there's one product. It's always something to keep in mind and double check.
If you are referring to the orientation of the beta proton, that is covered in my tutorial on E2 on cyclic systems. If you actually meant regiochemistry, that is covered in my tutorial on Zaitsev vs. Hofmann elimination products.
sir
what transition state is formed in E2 and E1 mechanism?
for E2 it's all concerted, and you can see that in this clip. for E1 we have the carbocation intermediate.
where did the H2O come from in the products
Hydroxide grabs a proton and becomes water.
Can solvent influence the reaction mechanism??and how??
sure, polar protic solvents make mechanisms with carbocation intermediates more favorable, they also reverse the nucleophilicity trend of the halides, stuff like that.
Thank u sir
man you are my GOD you saved me
sir what is mean by SN1 PLZ explain sir
check out my tutorial on SN1!
please how can i know the difference between E1 and E2 ?
+Hanane Kika it's all in the clips! if you have a more specific question feel free to email me.
Sir, what is stereochemical demand for occuring this reaction?
only that the proton and leaving group be anticoplanar, check out my tutorial about E2 on cyclic systems
Prof. Dave Ji ( In Malayalam Dave = Dev ( The God) . You mechanically acted like God to us guys though. Am from Kerala S. India. Am a Tutor and love to view your videos for finalized notes. Teaching upto plus two. Expecting your valuable videos still. Corona is not a joke. Really creepy when the educational arena is considered. You do rock Sir. Take Care please. Saareeyakal Sir !!!
🙏🙏🙏
Professor
I have another doubt that in nuclear reactions how the nucleus combined
check out my tutorial on nuclear reactions in the general chemistry playlist!
what's the difference between an alpha and a beta carbon?
spatial relationship to some functional group being referenced
@@ProfessorDaveExplains in the video the alpha is attached to the bromine and then the beta is attached to a hydrogen and methyl group so I guess I just don't understand how to identify what is what. Is there a general rule to it?
They're just relative terms, in this case they reference the halogen. Alpha means one away, so the carbon attached to the halogen is alpha to the halogen, and any carbon one further away than the alpha carbon is a beta carbon.
@@ProfessorDaveExplains OH MY GOSH YES BECAUSE OF THE ALKYL HALIDE, okay I get it now thank you so much professor
You are awesome
How to say hybridization of any organic and non organic compounds by easy way
check out my tutorial on VSEPR theory in the general chemistry playlist
Thank you very much sir
Can I ask you a question please?
If I have 2-bromobutane in an elimination reaction
then what would the product be
But-1-en or But-2-en or both?
Thanks in advance 🌺🌺
yep could be either, depends on the base, and often will get a mixture too. check out my tutorial on zaitsev vs. hofmann elimination products.
How do I go through a semester and not understand this? And yet within your short videos I do...?
Sir please sn1 reaction
I have tutorials on all the mechanisms, go to my organic chemistry playlist.
@@ProfessorDaveExplains ok sir
And I subscribed ur channel sir
Hi Professor Dave,
I'm having trouble doing an E2 reaction when given a molecule in a Fischer projection. My current method is to convert the Fischer projection to a sawhorse, then to a Newman, then finally the final product. However, this process is very tedious and I always end up making mistakes. Is there a better way of doing this starting with a Fischer projection?
Fischers are annoying, huh? I've never done eliminations that way, you definitely don't need Newmans, but the best way to be sure is to convert into line notation and do it that way. Otherwise you can probably do them right on the Fischer, you just have to make sure the stereochemistry works.
Why doesn't this undergo a substitution reaction instead?
+AstridMPerez it certainly could! i'm just outlining the E2 mechanism. to decide which would occur you'd need to know more about solvent, temperature, etc, and if just given these compounds in a general sense, both mechanisms would occur and you'd get a mixture of products.
thankyou chemistry jesus
Who sings the intro?
me
@@ProfessorDaveExplains huh I guess i just haven't heard your singing voice other than that🤔
this isn’t wlr v1
won't that carbon atom in the end become a cation?
nope, concerted reaction, no formal charges!
oh. thx
❤❤
👌👌👌
10 numara 5 yıldız
I send my thanks to you with a prayer, may Allah open your heart to Islam.
God bless but Jesus is God
@@Obamnaz Surah al-Ikhlas [112:1-4] ;
Say, “He is God, the One.
God, the Absolute.
He begets not, nor was He begotten.
And there is nothing comparable to Him.”
Surah al-Ikhlas [112:1-4]
All prophets, from Adam, the first prophet, to Muhammad, the last prophet, were human. The duty of the prophets was to teach people about the existence and unity of the Creator and to show them the right path. The duty of Joseph, Noah, Abraham, Jesus, Moses and Muhammad and all pther Probhets of Allah was to call people to believe in the oneness of Allah. Prophet Jesus was a human being like other prophets, he ate, slept, walked on earth, how do you qualify a human as God? How would you characterize the Creator, who created and rules the entire universe, all living things, and the entire universe, as human? Creator is eternal. He doesn't need to eat, drink or sleep like us humans. He does need anything. He does not eat, drink, sleep. It is free from all deficiencies and shortcomings. He is one. He is all-knowing, all-seeing.
@@Obamnaz “O People of the Scripture, do not commit excess in your religion or say about Allah except the truth. The Messiah, Jesus the son of Mary, was but a messenger of Allah and His word which He directed to Mary and a soul [created at a command] from Him. So believe in Allah and His messengers. And do not say, "Three"; desist - it is better for you. Indeed, Allah is but one God. Exalted is He above having a son. To Him belongs whatever is in the heavens and whatever is on the earth. And sufficient is Allah as Disposer of affairs.”
Surah An-Nisa 171.verse [4:171]
And [beware the Day] when Allah will say, "O Jesus, Son of Mary, did you say to the people, 'Take me and my mother as deities besides Allah ?'" He will say, "Exalted are You! It was not for me to say that to which I have no right. If I had said it, You would have known it. You know what is within myself, and I do not know what is within Yourself. Indeed, it is You who is Knower of the unseen.
I said not to them except what You commanded me - to worship Allah , my Lord and your Lord. And I was a witness over them as long as I was among them; but when You took me up, You were the Observer over them, and You are, over all things, Witness.
Surah Maidah [5:116-117]
My friend, you are saying a heavy word, I hope you research, read and learn. I hope you hear the call of Jesus and all the other prophets and you will believe that the God, the Creator and Sovereign of the universe is one. There is no God but Allah. Take care of yourself, have a nice day.
And you can listen Surah Al-Maidah, there is speech of Jesus PBUH with Allah.
Fuck Islam 🖕
@@Alminaa55...girl??study instead of doing this 😂😂😂
What is your last name? You can trust me.
My friend Christen and I are wondering if you two are cousins because the physical resemblance is so striking.
all my cousins live in italy!
Professor Dave Explains oh.
This has to be the ripest channel