Oxidizing Agent

alright guys not want to dive a little deeper into the re agents of oxidation. So just you know, all of these regions that we're gonna talk about in this topic can be generalized as oxidizing agents. Okay, Now, I remember when I was in Jenkin and you had, like, oxidizing agents, reducing agents. Oxidation is kind of confusing. Sometimes, like the oxidizing agent gets reduced, there's a lot of different stuff up to memorize. Um, or maybe I was just stupid. I don't know, but all I know is that in or go, it's really not complicated at all. All you have to think about is that the oxidizing agent is the thing that oxidizes your molecule. Okay, so if you're trying to oxidize molecule, make more bonds to oxygen, you're going to use an oxidizing agent. It's that easy. Okay, so, um, what's There's a general rule they really need to follow with all these reactions. Even if you don't know the mechanism, there's just a rule that you can use. And that's that oxidizing agents are gonna add as much oxygen as possible while not breaking any carbon carbon bonds. Okay, now, this is a little bit of a lie. There are some oxidizing regents oxidizing regents that can break carbon carbon bonds. Okay, some examples that you might already know would be, for example, owes analysis. Okay, That would be an example of an oxidation that can. But that's what we're going to talk about in this topic. That's its own separate topic. Right now. I'm trying to deal with these oxidizing agents that don't break carbon carbon bonds. Okay, so I'll get to what they are in a second. But even before we know what the re agents are, we could already jump into a practice problem. What I'm wondering is out of these four molecules here, which of them actually could be oxidized? What I'm basically saying is, how many of them could you add? Bonds toe oxygen without breaking a carbon carbon bond? All right, so I'm gonna go ahead and let you guys figure that out. Get back to me. Which of these could be oxidized?

All right. So I hope that you didn't say all of them. Because there are some that can, and some that can't let me give you an example. The first one there's a carbon here that has a bond to an oxygen has to bonds to carbon. And then it has one bond to H. Would you agree with that? Okay, so now my question is, is there a way that I could turn this carbon into a carbon that has more bonds toe oxygen? Okay. And here's the way up to think about you have to think Well, how many bonds to carbon does it already have? Has to has won two bonds to carbon. Is that cool so far since as to bonds to carbon. How maney total bonds Could it have toe oxygen? Theoretically to because no matter what, carbon could on Leah. Four bonds. So what that means is that if has to bonds to carbon later on, I could oxidized. It's that it has to bonds toe oxygen. Alright. So could this be oxidized? Yes, this could be oxidized because I could make it in the form where there's two bonds to oxygen. All right, So let's move on to the next one. The next one. This carbon. Could it be oxidized? No. This one is not gonna be able to be oxidized because noticed that it already has its maximum number of bonds. Oxygen, Because has two carbons 12 Is there a way to add a third bond to oxygen? No. Okay, let's move on to three. Could three be oxidized? Yes. OK, because it only has one bond to carbon. So that means if it only has one bond to carbon, then it could have how many bonds to oxygen? Three. How many bonds does I have right now? Onley One. So it could actually be oxidized more than once. OK, and then finally we have compound number 43 gets a check. Mark four. Could this carbon be oxidized? Yes, once again, because it only has one bonds of carbon. So that means that we could take away that h. And we could make another bond to oxygen there. All right, so that's the way that it works. All of these could be oxidized, except for two, which can't, because it already has the maximum number of bonds to carbon and oxygen. All right, So what reagents are gonna do this? Well, strong oxidizing agents are agents that are going to add the maximum number of oxygen's possible while following the rule of not breaking any carbons. Okay, these re agents are gonna be cam in all four. Okay, Canada four is a region that you've probably already seen. But in case you haven't potassium permanganate. Very strong oxidizing agent. Also your chromium six re agents. Okay, now it's a CR six. Plus, remember, that is the oxidation state of the atom. You are not going to calculate oxidation states in organic chemistry. But you should know is that if you see chromium present in any of these weird molecules, these are all examples of strong oxidizing agents. Okay, It turns out there's more re agents than this. The Jones re agent is an example of of a chromium re agent. Okay. Where Jones region would use c r. 03 and sulfuric acid. Okay, so I'm trying to say is that as long as you see some kind of chromium in the regent think this is a strong oxidizing agent, you don't have to actually calculate out the oxidation state Okay, So what I want us to do for this next practice problem is go ahead and draw the new oxidation products of each of these molecules. Okay, So I want four different things in these boxes. If it's not going to react, put no reaction, Okay? But I want to see all the different oxidation products, so go ahead and try to do the first one.

So let's go ahead and look at this first one. What I would get is a carbon that now has two bonds to carbon. So I should draw that six numbered ring just like before. But now it's gonna have to bonds toe oxygen. So what I'm expecting to get here is a key tone. Okay? Why a key tone? Because a key tone would be the version of that carbon has to bonds toe oxygen. Now you might be like Johnny. How would I know if it's a key tone? How? But if it's another functional group, I don't want you to think about the functional group. Honestly, all I want you to think is how maney bonds to oxygen does. This thing is this thing able to make in this case that carbon could make to bonds to oxygen because that's why you draw to bonds to oxygen and a cyclo hexane on the other side. All right, so go ahead now and try to do the other three another. You have an example. Try to draw the other three structures, put them in the box and see if you get the right products

All right, so this first one would be no reaction. We know that because we said that the second molecule can't be oxidized at all. So there's no point and even drawing a product now, the third one is interesting because we talked. We talked about how this carbon right here has only one bond toe, another carbon. So that means it has one bond to carbon. How maney Oxygen's Can it possibly have three. So what that means is that I need to draw a version of this carbon that's gonna three bonds to oxygen. If you looked at our intro to Redox chart, where I talk about things that are getting oxidized and things they're getting reduced. Okay, The version of carbon with three oxygen's would be a carb oxalic acid. So what I would do is I would draw that carbon with a dull bond. Oh, and with an O. H. Okay. What that's going to do is now that's gonna keep my carbon carbon bonds. So I'm not breaking the rule. I'm not breaking that bond, but now I have one, 23 bonds, toe oxygen. All right, cool. So no. How about this last one Well, this last one, I'll move out of the way. Stairs can see it. This last one you will find is that that carbon once again on Lee had to bonds to I mean, I only had one bond to carbon, but it already had one to bonds oxygen. Okay, so how many extra bonds oxygen couldn't have? Well, we already have. We just know that the rule says you can You can Onley have four bonds, and one of them has to be a carbon. So that means that the last third bond could also be an oxygen. So what I'm gonna do here is I'm going to try to move out of the way here. I'm going to draw this molecule once again. Also as a car. Books like acid. Why? Because basically, when you're oxidizing something that has one bonds of carbon, that means it's gonna have three bonds toe oxygen. And when you have three bonds toe oxygen, you wanted to look like a carb oxalic acid. Okay. When you have to bonds toe oxygen, you want to look like a key tone. And then we have one bonds oxygen. You wanted to look like an alcohol, which is the one that I have up there. Okay, Bueno. Pretty good. Awesome. So now what I want to do is I want to show you guys another re agent. It turns out that even though we deal with strong oxidizing agents a lot, there's also a regent that's called a week oxidizing agent. Okay, now, week oxidizing agent would simply be one that doesn't oxidized multiple times. Okay, Um, the way that we're gonna define it in particular is that it can Onley add one equivalent of oxygen to primary alcohols. That's really the only difference. So what that means is that it's going to do the same thing as all the other re agents Camel for chromium six. Same thing, except in one situation in a primary alcohol. Instead of going all the way to carve oxalic acid, it's gonna It's gonna go one equivalent instead of two equivalents of oxygen. So let me show you what that looks like. Okay, So PCC is the name of this re agent, and it is our week oxidizing agent. So would it be ableto oxidize my secondary alcohol? Absolutely. It's going to do the same exact thing. So for PCC. I would get the same exact reagent here or the same exact product. Okay. Would it be ableto oxidize number two? No, nothing can oxidize number two. It's still no reaction. Okay. Would it be ableto oxidize number three? Yes, it would, but this is our special situation. Notice that I have a primary alcohol. Okay, whenever you have a primary alcohol, what that means is that for a strong oxidizing agent, I would have taken it to a carb oxalic acid like this, but for a week oxidizing Agent PCC, I'm gonna go to an alga hide instead. So that means that I'm actually gonna draw this thing like this with an H instead of an O. H. Okay, that's the biggest difference here. That's actually the Onley major difference that we have with PCC is that instead of getting carb oxalic acid, we get an alga hide. Okay, now you might be wondering, Johnny, What do you mean by one equivalent of oxygen? All I mean is that notice that at the beginning how maney bonds oxygen Did we have We had one. I'm just gonna say 10 okay. At the end of the strong oxidation. How Maney did we have bonds to oxygen? We had 330 okay. So that means that if we had one oxygen to begin with and three to end with, we added two equivalent of oxygen. Okay, well, for PCC instead of using doing to equipments of oxygen Now, we're only gonna add one equivalent, because now we have two buns to O instead of one, which is what it started with. So if you're starting with one, and yet with two, that means you only added one equivalent of oxygen. And that's what this definition has to do with. Okay, But if you want to remember, just say that primary alcohols go to Aldo hides. That's another way of saying it. That's maybe less complicated. And that's always right. Okay. You could just say it like that the rest of your life if you want to, and that's fine. Okay, let's get down to our last structure. Would it be ableto oxidize my four. Okay. And the answer is no. This would be no reaction. Why is that? Well, because it's already an alga hide. Okay, notice that Alba hide is the product of PCC, right? PCC is gonna make an alga hide. So if we haven't alga had already isn't gonna do anything to it. No. Okay, so once it's now the height, it's not gonna oxidize it more. This would be no reaction as well. Okay, So just trying to show you guys the difference between PCC and the other oxidizing agents. It's not that hard. It's just a few details you have tow. Keep in mind. All right, so that said, let's go ahead and move on.

Now that we understand the process of oxidation pretty well, I want to show you guys at least one example mechanism of oxidation. So you'll understand kind of the electron movement that creates this oxidative environment. So, guys, one of the most common regents that's used for oxidation is Jones re agent and Jones Re agent is the name that we give to the combination of a chromium six plus re agent in strong acid. So this takes a lot of different forms, and you'll see it written a lot of different ways. But essentially, this would be the combination of crow three with something like h two s 04 This is very, very common. But you will see it other ways because once the HBO so four reacts with the crow three it's going to it's going to change, and it's gonna look a little bit different. But as long as you see a chromium region with a strong acid, that's pretty much a Jones free agent. Okay, so what I want to do is I want to take you guys through this mechanism step by step, and what we're going to start off with is an alcohol is, you can notice we're starting off with a secondary alcohol. So what would we expect a secondary alcohol to become after it reacts with a strong oxidizing agent? Well, remember that you can Onley oxidized as much as you can without breaking carbon carbon bonds. So what that means is that if it's a secondary alcohol and I need to keep both of those are groups, they're the most. That this could become is a key tone. Okay, so, actually, that's what we're trying to do. What we're trying to do is we're trying to get rid of this alcohol, get rid of this age and make Keto. How is that gonna work? Well, let's go ahead and start the first step. Guises nuclear feel like attack, because here we have chronic acid chrome ic acid, which is formed by the chromium and the acid. Reacting together and chronic acid is kind of unique because it's got all these crazy die polls pulling away from the chromium. What kind of reactivity do you think the chromium is going to display? Guys, it's gonna be a super strong electro file, right? Because it's got basically no electrons. So in our first step, we would expect the alcohol. That's a decent nuclear file. It's got electrons on it to attack the chromium. Okay, now, the chromium already has enough bonds. That doesn't want more. So if we make a bond, we have to break a bond. So one of these double bonds is gonna become an anti on. So I would expect that I would get a own negative, but we're in the presence of acid, so the own negative is going to protein eat. Right? And then that's what I'm gonna get. I'm gonna get O h there instead of the double bond. Okay, so now basically one step forward, we get this huge molecule, and I know that it can be difficult to keep track of where things are. So I'm gonna use colors to show you where everything is. Okay, let's start off with the nuclear feel like attack this Ohh. Here is now right here attached to the chromium and still has an h on it. Yeah, let's go to another easy one. This a waitress? Still here? Okay, so nothing changed there. This a wage is still here. Okay, so there's still in the places that they were before. But there is one new a wage. That's the one that is in pink. Because this pink remember that it grabbed in H, right. So that means that this is the O. H. Here. Okay, so now hopefully those colors help you to kind of identify what's going on. Where everything go. All the atoms, they're still there. So we're doing okay. All right, So now we did our nuclear Filic attack. The next step is Ah, very kind of interesting and rare step called Alfa Elimination. Guys, you've heard of elimination reactions already? They make double ones, right? And we've always dealt with beta elimination. Bait elimination is kind of just the go to elimination that we use. But in some specific mechanisms in organic chemistry, we actually see Alfa eliminations take place. And oxidation is one of them. Oxidation mechanisms have a lot of Alfa elimination. So what Alfa simply means is that instead of eliminating between the alpha and the beta carbon, right, you're actually gonna form a double bond directly on that Alfa Carbon to something that's not a carbon. Okay, So in the next step, I'm gonna eliminate This is my Alfa carbon because it's the one that has the oxygen on it. If I were to say, you know, this is an Alfa Alcohol is where my alcohol is. My Alfa carbon is the one that's attached to the alcohol. Well, you d protein e with a conjugate base of whatever your ass. It was water in this case. And instead of forming a double bond between two carbons, I just formed a bond directly on that carbon and a non carbon Adam like, Oh, okay, now, now the O needs to break upon because the oh isn't happy having that many bonds. So the O is gonna break up on, and actually, it's gonna do another Alfa elimination. So this don't want is gonna break and make a double bond in this. Oh, and then finally, that oh, isn't happy. So we're gonna take, um so we're going to basically get rid of that h eventually with water. Okay, it's not gonna happen on this step. In fact, maybe I just won't draw that right now because that would happen in a second step. But eventually you haven't o. H. And then it gets deep ruminated. Okay, awesome. So the most important part here, guys, is not what happens to the chronic acid after, because I don't really care. That was just my oxidizing agent. What I'm really concerned about is what's happening to this carbon. Okay, well, it's looking a lot more like a key tone is in it Because what I did was I made a double bond between the sea and the, uh Oh, and those two are groups were still there, and I got rid of the age. So now what I'm gonna have is this. Oh, it needs to be deep rotated, and I can be protein ate it with water or whatever other congregate you want. And what you're gonna get is a key tone. Cool. You're gonna get a key tone. Plus, you'll get your chronic acid that eventually reformed, so you'll get something. Looks like this. Okay, but we don't really care about that because that's just the oxidizing agent. What we really need to be able to draw here is how to get to the key tone. Cool, awesome guys. So hopefully it helps you understand the process of oxidation a little bit better. And also it introduces the concept of an Alfa elimination which will come up again in other reactions

Alright, guys. And we're going to do some practice problems involving oxidation. The two big things you have to remember our that you can't break carbon carbon bonds And also how to tell the difference between a strong and a week oxidizing agent. All right, so now go ahead and try to do the first problem.