hello organic chemistry students in this video we're going to introduce carbonal and what their functional groups are and the classes of carbonal functional groups and then we're going to dive into class one carbonal now we've already seen a lot of these functional groups before we actually seen them all before but we're just now going to categorize them in different ways now the first ones that we want to look at are going to be Esters carboxilic acids amids and in hydrides now all of these are part of what we call class one carbonal chemistry why are they grouped together if we were to look down here at the an at the anhydride if a nucleophile came into this anhydride it would attack one of the carbonal break open the double bond those electrons would donate back down because we can kick out this oxygen and carbon yal what we would end up forming here is that we have this nucleophile added onto one of the carbon yals of the former anhydride and we have now just kicked out this oxygen now this oxygen has direct resonance stabilization which means it is a good leaving group and that's all what class one carbon yals have in common or share in in common good leaving groups so here we can get this amine to be aing group this oxygen and carbon chain or this o right here and that is why we classify them as class one carbon let's see what happens with some other ones down below we have an alahh and a ketone now in each one of these cases when a nucleophile attacks this carbon yield we break open the double bond and stop that's it nothing is going to leave and let's go ahead and look at this and ask ourselves why so here's the nucleophile and I'm going to go ahead and show that hydrogen so before we work up this reaction we have a negative charge on this oxygen now we had a negative charge on the oxygen right here as well but it donated down to kick out the leaving group here if this negative charge donated down we would have to lose this hydrogen and these two electrons as a hydride good idea or bad idea and that's a bad idea horrible idea so we can't kick out a hydride we're not going to kick out the nucleophile we just added in unless it's an extremely good leaving group a Ka bad nucleophile and we're not going to kick out this carbon chain because if we donate these electrons down and these electrons go on carbon we've created a carban very unstable so what's the unique characteristic about class two carbon yields which once again are aldhy and ketones they have bad leaving groups that's the big thing class one has good leaving groups class two does not contain a leaving group Oh and before before I forget there is one more class one that I forgot about and those are the acid chlorides you can imagine a chloride being a wonderful leaving group as all halogens are so the big difference between class one class 2 leaving groups and that's it now we have a third class and that is this last one down below now I'm writing Z and R right here it could be oxygen nitrogen oxygen I said oxygen twice uh carbon hydrogen anything like that all we're caring about in this class three functional group of carbon yals is that we're looking at this carbon directly attached to the carbon yel and that's what we call the alpha carbon so any carbon directly attached to the carbon yel is considered Alpha any hydrogens on that Alpha carbon are called Alpha hydrogens now Alpha hydrogens are acidic so if a base came in we could pull this proton push electrons down between this carbon oxygen Bond actually I'll go ahead and stop for one second and let's reverse that and I'll just have the electrons go right onto this carbon and I'm not going to do reversible arrows like that because we're going to use strong bases in this class only and I have just made a carbon with a full out negative charge that seems horrible just like we did up above but this is unique because the negative charge could donate electrons down and resonate through the carbon oxygen double bond and that's what we can't do in class 2 this is unique into class three and this is going to allow us to form something called an enolate this enolate will do different types of chemistry that we will learn about in a future video but that is class three carbonal chemistry so while carbonal chemistry 1 versus 2 is talking about the leaving group ability of one of the groups on the carbon of the carbonal class three is looking at the hydrogens on the Alpha carbon so we can have class 3 carbon yield chemistry occurring in class 2 or class 1 because we have Alpha carbons in both those cases but we're not going to be looking at class 1 and two and class three so even though we have a one and a two class three we we just care about this acidic hydrogen right here and that's it so now let's go ahead and talk about class one carbon yo chemistry all right so here's our basic reaction for class one carbon yields what we're going to see here is that a nucleophile will come in attack this carbon of the carbonal let me go ahead and show the arrows we attack the carbon of the carbon yel we break open the pi Bond when this is done we have formed this intermediate right here that we call the tetrahedral transition state this carbon is now sp3 hybridized that's very important because when we remember back to our sub substitution and elimination chemistry those only happen on sp3 hybridized carbons now this is not substitution or elimination chemistry but the concepts are the same this is carbonal chemistry class one so the nucleophile attacks the carbon of the carbonal that SP2 hybridized carbon and we form our tetrahedral transition state but now if you notice we have equilibrium arrows this complex could donate down and push out the nucleophile to reform our starting material that is 100% possible or the negative charge could donate down and kick out the x or the Z oxygen the haly the nitrogen or whatnot to form this new carbonal species and kicking out the x and z this is the basic reaction of all class one carbonal it's going to be relatively straightforward but now how do we know which way this equilibrium goes if the nucleophile that we have right here is more reative active than the x and z that are kicked out we're going to favor pushing this towards the right let me say that again if the nucleophile is more reactive than the x or Z we push the reaction to the right another way of putting it if the nucleophile is more unstable than x and z meaning x and z is more stable we want to form that more stable species but now if the nucleophile is more stable than x and z we're not going to kick out the XZ here when the electrons donate down will kick out the nucleophile and return us the starting material so that's how we decide which way the equilibrium is being favored if the nucleophile is strong we favor the right if it's very weak we favor the left right there now like I said believe it or not this is the mechanism we're going to see for all class one carbon yields very little deviation right here let's go ahead and jump right into it the very first one that we're going to start to talk about is the most favorite oops let's go and change this and those are the acid chlorides this also works with acid bromides or acid iodines but acid chlorides are the classic ones to use now I just want to take this and throw in water or oh minus either or when this happens the oxygen from either species will attack the carbon of the carbonal break open the carbon oxygen double bond and what do we end up forming here you got it our tetrahedral transition state where here is that species and we'll write proton transfer as well in the case of water because we lose one of these protons when we form this species right here so now at this point this negative charge is going to donate down and it has a choice to make does it kick out oh minus or CL what's the better leaving group oxygen with a negative charge or c CL with a negative charge and it's CL because the halogens are far more stable with a negative charge than oxygen is even though oxygen is an electr negative element it can't stabilize it that well so what we've just done here is we've taken this acid chloride and you might want to write that down and we've transformed it into a carboxilic acid wow so the reactions that we're going to be covering here in class one carbon yields are going to show the interconversion between the different class one um functional groups this is how we can take an acid chloride and form a carboxilic acid let's move this oops let's move this up so we can still see that erase that random line let's take that acid chloride again this time I'm going to go ahead and take it and react it with an alcohol ethanol right here the pair of electrons on the oxygen can wrap around attack the carbon of the carbon break open the carbon oxygen double bond forming our tetrahedral transition States and we're going to write proton transfer as well because we'll lose that proton right here now a choice has to be made can this negative charge donate down and kick out the CL minus versus if we don't broke electrons from this Bond and gave it to oxygen an O minus oh wait haven't we already answered that question we did up above CL minus is far more happier with a negative charge than oxygen minus so we end up kicking out the CL and we end up forming this group right here and what functional group do you think this is right here starting with an acid chloride we added in an alcohol and we have formed a Esther so now acid chlorides with water or o form carboxilic acids acid chlorides with alcohols form Esters wow so easy to do and they work so well because chlorine is a great leaving group now what if I took this acid chloride and reacted it with this amine right here we have lone pairs of electrons on the amine they could wrap around attack the carbon to the carbon yel break open the carbon oxygen double bond and I know right now you're like this sounds familiar it is same reaction over and over again we do a proton transfer in here losing one of the protons on this nitrogen to form this tetrahedral intermediate the oxygen with the negative charge donates down we kick out the chlorine because it is the best leaving group in these systems and we have now just formed an Amid and cl minus so an acid chloride is we can take an acid chloride and transform it into a carboxilic acid with water or o minus into an ester with an alcohol into an amid with an amine wow we've taken an acid chloride and almost transformed it into each one of the functional groups of class one except one of them let's take this acid chloride and I'm going to react it now with a carboxilic acid we have a lone of electrons on this oxygen that could wrap around attack this carbon of the carbonal break open the double bond to form our tetrahedral transition States I know oh my gosh saying the same thing again we lost that proton in the carboxilic acid so there's our proton transfer we donate electrons down and chlorine is still the better leaving group even though the other compound when it leaves we could have resonance chlorine is a a great leaving group and in this we have just formed an anhydride so acid chlorides can be elaborated onto carboxilic acids Esters amids and anhydrides wonderful so we see the power of an acid chloride do all class ones have this power and let's go ahead and look at that next but before I jump into this next slide I want to ask the question the nucleophile attacks the carbon of the carbon yiel in each case the negative charge donates down and kicks out the chlorine nothing else is required this is a good reaction it works very very smoothly let's see if the rest of them do the next one that we're going to talk about is going to be carboxilic acids all right so with a carboxilic acid let's go ahead and look at this one right here I'm I'm going to take a carboxilic acid and I'm going to see if I can react it with an alcohol so now this alcohol is going to wrap around attack this carbon right here break open the carbon oxygen double bond same thing that we've been seeing before and now I'm going to show you the tetrahedral transition States but I'm leaving this proton on right here but in the acid chlorides I did not leave it in the acid chlorides it does not matter if this oxygen is protonated or not the chloride is a superb leaving group bromine great leaving group iodine superb leaving group they all go just fine here this is a problem so now in red if this negative charge donates down we're going to kick out this alcohol or not this alcohol call this o minus right here and what we are going to end up forming is here's our proton right here oh minus hm is oh minus more stable or less stable than this ethanol and the answer is less stable which means this doesn't happen whatsoever rather than doing this Arrow right here we will push out the nucleophile that we added in and just just get back our carboxilic acid why is that when we look at the O minus out of these this right here this o minus or this proteinated oxygen what's the better leaving group the oxygen that's proteinated because if as the electrons come back down to oxygen it neutralizes the molecule neutral carboxilic acid so we get full reversability nothing carrying on because this negatively negatively charged oxygen must react it's very highly charged it needs to undergo chemistry so if only we could add something in that would help stabilize this negative charge to allow for that lower oxygen to lose its proton so same conditions nothing different what are we going to add in now H+ that's it the oxygen that is SP2 hybridized will pick up that proton rapidly and we have now formed we we call an activated carbonal that Oxygen's a full out positive charge meaning we're pulling more electron density up to this oxygen from this carbon making this carbon partially positive and that allows the alcohol to attack it rapidly and push electrons to this oxygen now we do have this being reversible just as in all cases and what we end up forming is I know you're like wait this is the same exact thing that we just drew up above and it almost is what's the difference between this compound and this intermediate here neutral negative very reactive stable so now because it's so stable down below it allows time for that oxygen to lose the hydrogen this is a reversible process as well and we've now neutralize that lower oxygen and we have H+ sitting in solution o is a bad leaving group now if this oxygen donates electrons down or if this oxygen donates electrons down it doesn't matter which one of those does the important thing is this lower oxygen can never donate electrons down because there's no hydrogen on it for it to leave so what I'm going to do right now is look at this top oxygen and look at those lone pairs one of those lone pairs can pick up this proton right here when we pick up this proton in a reversible process now once again please keep in mind that either o could have picked up this proton we've now formed what looks like water the lone pair on the other oxygen will donate down and push this water molecule out and what we form here is a carbonal with a hydrogen on it attached to a carbon chain we then lose this proton and when the reaction is all said and done we have just formed an Esther wow so many more steps in the acid chloride why acid chlorides have superb leaving groups they're highly activated we do not need to do this activation of the carbon yield like we're doing here with an carboxylic acid we have to add H+ to activate the carbon yel to allow this transition state time to lose this proton so something that we didn't need in the acid chlorites because the chlorine was a superb leaving group we lose the proton the proton is picked up by either one of these O's once again does not matter then the other o will donate its electrons down to push out that water molecule we lose this proton and we form our Esther functional group wonderful so an acid chloride can be converted to a carboxilic acid an Esther an Amid and an anhydride a carboxilic acid can be converted to a Esther so far let's see if we can do anything else oops let me get the my pen in here all right let's take this carboxilic acid and I am going to react it with an amine now just like we had up above the amine is going to attack the carbon of the carbonal but we still are going to form a negatively charged transition state so we need to add in H+ don't we to activate the carbon yal so we would think in this reaction nothing happens we don't form anything I know who wait a second why nitrogen with its lone pairs is a basic molecule and it picks up the protons rapidly while oxygen has lone pairs of electrons oxygens are not basic nitrogens are so what we form here is an NH3 we're not protonating the carbonal and no reaction can take place so so so far with carboxilic acids we can form an Esther we cannot form an anhydride H problematic for sure let me move this up some oops move this up let's see if we can form an anhydride so if I take a carboxilic acid react it with H+ and I'm going to use the same exact carboxylic acid we're going to have this oxygen of the carbon yeld pick up this proton of course the other starting material could have picked it up as well we protonate that carbon yield just like we did before and now enters in our nucleophile we have lone pairs of electrons on this oxygen we can attack the carbon yield break open the double bond and we have now formed this O O oxygen carbon yal with a proton on it and these are reversible this positively charged oxygen will get it electrons back when that proton dissociates and we've now formed this o species and this carbon proton over in solution W either one of those oxygen could pick up this proton and then this oxygen will donate electrons down and push that water molecule out and following proton transfer we get out the an hydride functional group wow that's a lot of arrows but carboxilic acid reacting with the carboxilic acid under H+ has the same arrows as a carboxilic acid with H+ and an alcohol this reaction and this reaction are identical so carboxilic acids can be transformed into Esters carboxilic acids cannot be converted to amids but carboxilic acids can also be converted into you got it and hydrides so far acid chlorides are superior but notice I don't talk about how a carboxilic can become an an acid chloride we'll talk about that a little bit later so now let's look at the amid functional group so if we have an amid functional group right here if I add in H+ and H2O could that oxygen of the carbonal pick up the proton it should there's electrons on it right it doesn't nothing happens here whatsoever but wait we had all the conditions to do this just like we had on the previous page why doesn't anything happen here while this is the way that we draw an amid the way an amid truly exists in everyday life is as follows this is the true form of an amid under normal conditions such as room temperature these exist in dynamic equilibrium equilibrium here and if I can make that Arrow even smaller I would 99.99% here Trace Amounts here this right here though is the active form or I should say the unstable form down below this is the stable form or the unactive form so if we're staying in this form 99.99% of the time amids don't do a lot so how can we get this stable form into the unstable form we can do this transform it up this way by adding in heat so in order to do any chemistry on an amid we must add heat now before I go a step further if you think about being sick if you have a bacterial infection or anything like that you get a fever don't you our body's cranking up the temperature because we're trying to switch this to tomiz event here into here in the bacteria so our immune system can break down the proteins in the bacteria and kill it so the heat the fever is there to shift the population of the amid that's why we're doing it now if the temperature in your body gets too hot over 1005 I believe it is they pack you in ice why we then start doing a degradation of am in our brain we don't want that we don't want the brain to break down so that's why we have to stop the reaction so let's go ahead and take this concept of heat and apply it to our reaction now so we draw it in this form this is the way we always draw amids once again even though it exists in this form nearly all the time but that's the way we draw it this time I'm going to write H+ I'm going to write My H2O and I must always imply heat so we're in the reactive confirmer now this oxygen can pick up this proton because it actually is an SP2 hybridized oxygen we pick it up we form the activated carbon yield species and now water with its lone pair will attack the carbon yal break open the double bond in a reversible process and we have now formed this species here the nitrogen will pick up one of these protons giving electrons back to oxygen and we now have a protonated nitrogen wonderful one of these oxygens with its electrons will donate electrons down and push out our amine we do a proton transfer and we we have a carboxilic acid so an amid can be converted into a carboxilic acid with H+ water and heat wonderful what else can we do with an amid oops so an Amid and I'm going to not I'm not going to be pushing the arrows on this one because we now know what those arrows are they're the same things that we saw in previous slides so now I'm going to put H+ in and and an alcohol and heats so we know that the alcohol is going to switch places with this amine right here we know that's the fact we've seen the mechanism up above it doesn't change and we form this functional group here so an amid can be converted into a Esther you have it there it is so we can take an amid form a carboxilic acid we can take an amid form an Esther but we cannot take an Amid and form and hydde sadly that one doesn't work so that's our limitations here right there so we've talked about the acid chloride we've talked about the carboxilic acid we've talked about the amines the amid systems right we haven't talked about Esters yet so in an Esther we have the same problem once again we have to make sure that we neutralize this tetrahedral transition state so we're going to add some H+ in and I'm going to add water in now this is not an amid there is no tation to form this reactive species it's the Esther it's ready to go what we are going to form here is a carboxilic acid so whoa whoa wait a second I'm noticing a pattern now no matter what the carbon yel is the class one carbon yel when I add water or o minus I get a carboxilic acid wow no matter what the class one carbon yiel is when I add in an alcohol what do I always get oh I get an Esther Ah that's interesting and for the limited ones when I add in an nh2 we should get an amid out but here we don't get an amid out either why because the nitrogen's amines will pick up that proton and quench the reaction so carboxilic acids cannot be converted to amids nor can Esters right here so we've talked about four of the five class one carbonal functional groups what's left and hydrides now notice I'm not starting a new page I'm just going to draw the anhydride right here an anhydride with a nucleophile being present when it attacks one of those carbon yields we break open the double bond donate electrons down and kick out our super good leaving group to form this resonance stabilized Le leing group now this is a good leaving group just like chlorine is so the anhydrides can do the same chemistry that the acid chlorides can do we can take an anhydride and form a carboxilic acid where this is an o or we can form an Esther where this is an O group or we can form an amid where this is an NH with r or hydrogen also attached same exact chemistry wonderful so now we've taken all of these groups transformed them into carboxilic acids amids Esters and anhydrides what's the one thing we haven't done form the acid chloride how do we form an acid chloride and we're going to do this right here on this page before we end the video so how is an acid chloride formed in one way only we take a carboxilic acid and we're going to react it with Thal chloride to form form the acid chloride in this we've seen this already when we looked at the halide video the alcohol not the alcohol I'm sorry this oxygen will attack the sulfur break open the double bond donate electrons down and kick out the chlorine and what we have formed here is this oxygen oops that negative charge should not be there there's the double bond here's this oxygen hydrogen attached to sulfur doubly bound with a CL minus positive charge here we can lose this proton right here and I'm going to go ahead and just erase it oops I'm going to erase it I can't erase it now because I wrote on top of it so I'm going to have to go ahead and show the proton transfer step I was just going to erase it and put PT over the arrow so now we have a chlorine sitting in solution that chlorine will come in Attack the carbon of the carbonal break open electrons don't electrons down and do the same exact reaction that we saw when we converted an alcohol into you got it a chloride and that converts them into our acid chlorides as shown so with this in this video we have very nicely shown how acid chlorides can be converted into the other four class one functional groups great we then showed how carbon oxyc acids and Esters have limitations right they can be converted into alcohols I'm sorry carboxilic acids Esters and hydrides but not amids amids themselves can be transformed into other functional groups of class one but we have to add heat absolutely there's no if ands or buts and then we talked about the anhydrites so now we need to come up with an overall order of reactivity of class one functional groups clearly the a chlorides do all the great chemistry it has the best leaving group on it the next one that has the best leaving group are the anhydrides now we have to fill in these last three boxes right here I'll put little lines in we have the anhydrides we have the carboxilic acids and we have the Esters carboxilic acids and Esters are similar to one another aren't they they are so we're going to say they're equal but do they react better than amids and the answer is yes an amid you have to add heat to do tization and try to get the reaction to go and that's why they are dead last in terms of their reactivity so what we're going to do in this class is get rid of this greater than sign and we are going to say is that the carboxilic acids and the Esters have the same functionality reaction rates so with that this ends the video on class one carbon y chemistry hopefully you've noticed the same mechanism over and over and over again I know um what I'd recommend doing is watch this video again take more notes on this and practice the mechanisms and come back and watch this video to find out how you did with that if you have any questions please feel free to send me an email um see me after or see me the discussion or office hours and I'll be happy to help you the best that I can I hope each of you are doing well and I look forward to seeing you sometime soon