Reductive Amination

Hey, guys, in this video, we're gonna cook up a really important reaction called reductive emanation. So, guys recall back to your key tones and Alba hide section of the text that ketones and Alba Heights when reacted with a primary amine in acidic environment, what would you get? You would get the functional group called in in mean. Okay, now, what was an Indian? Well, remember that in Imean is just a carbon carbon. But instead of the O being attached to the sea, you're gonna replace that. Oh, with an end. And that end could be attached to upto one are groups. Okay. Now, the reason that it can be to our groups is because that would be called in enemy and the double bond would be in a different spot. So we're not gonna be talking about any means here. We're only talking about Indians. Well, guys, this mechanism was a reversible reaction. Remember that you have your double sided equilibrium arrows showing that you could go from the carbon eel to the I mean and then back to the carbon Neil. But regardless of which direction you're going, you always had to pass through a pretty important Intermediate. That intermediate was called the women IAM cat ion. Thea Mini. Um, Catalan was an intermediate where your nitrogen had a positive charge on it. Okay, I'm not gonna draw it right now, but you'll see it in a little bit, okay? When I go through the mechanism now, guys, because this is a mechanism that I've already covered in another video. If you do want to brush up on the entire Imean mechanism, feel free to search in the clutch search bar. Type in. I mean, and this whole mechanism should pop ups you can refresh. Okay, Now, what I'm gonna do is, since I'm assuming that you guys can go back to that video and watch it for anything, I'll be teaching the abridged mechanism here. Why this is important is because the Imean mechanism is the first step of reduction. Reductive am a nation. So let's keep going. It turns out, guys that instead of, um, de protein ating at the end and making your in mean there's something else that you could do you could react with reducing agent called n a B h three c n. So what you could do is in your first step, you could make an Emmy. This is your first step. Notice how I have a nitrogen like ammonia and acid. That's what we would usually expect from an Emmy. But what's different about this reaction is that in the second step, I would use a reducing agent. Now, remember, reducing agent is one that adds hydrogen. So I'm just putting h in brackets just to generalize that there's a reducing agent and we're gonna find is that if you use the reducing agent in the second step instead of just leaving it as an m mean what you're gonna wind up getting is in a mean. As you can see, this is actually a primary amine. Okay, so it turns out that reductive and the nation is a really convenient way to make a means. Okay, So following the logic of these mechanisms, this is how it works. Guys, your first step, like we said, is the in mean reaction. Okay, so what you do is you take your carbon deal. In this case, this would be an alga hide, right? Al hide and I would react it with in a mean and acid like we have here. Okay. And what that would give you is this intermediate? This intermediate was called in imminent. Um, cat eye on this is the one I was referring to earlier. This is kind of this is the last step before we make our Emmy. Okay. Now, usually, what would happen is if we wanted to just make an m mean we would deep protein eight. Okay. So usually we would use some kind of base or conjugate to deep protein eight, take away the h, and you would usually get the Emmy, and that looks like this and h carbon h and we'd be done. This is called your Imean. Okay, But we're not going to do that, because in this reaction, we want to get rid of this double bond altogether. We don't want the double bond there anymore, because the double bond is an Emmy. But we want an ami. We want one that has just a single bond. So how can we add hydrogen? Is that double bond to make sure that it goes away basically, to reduce it, we can use my reducing agent. Okay, so this is going to be basically sodium borough hydride or on a beach. Four. Notice that it's almost the same. A Zen a beach four. But it has a scion of group on it. CNN. Now, what the C N is gonna do is it's an electron withdrawing group, so it's gonna make the sodium borough hydrate a little bit less strong of a reducing agent. Okay, this is actually gonna be mildly reducing. I'm just gonna right here, mildly reducing. Since it's mildly reducing, I don't have to worry about getting any kind of weird byproducts. All it's going to do is it's gonna add hydrogen is to the Taliban. Okay, so what we're gonna do is in the last step of the mechanism. Like I said, I'm not going to go through the hole in mean mechanism because this part of the mechanism, you can just watch the m E in video. Okay, if you want to know this part, okay. But I know that you're probably interested in this part you're wondering. Well, how does this happen? Okay. And that's what we're gonna go through now. Well, you've got your sodium borrow hydrating gonna put your be. It's got an h h two c n. Okay. And Let me just make sure that I have everything, right. Yeah, it looks good to me. What's gonna wind up happening, guys, is that, um And by the way, guys, because of the fact is, boron has four bonds on it, so it's gonna have a negative charge. Okay, now, where? When I wrote the sodium borrow hydride, I didn't write the negative charge. Where was that? We'll remember. Guys, there's a sodium around here, so the n a plus is counter counterbalancing. That's that's why it didn't write it as a negative charge. But once you ionized sodium away you you let it go into solution. You're gonna be left with this negative charge on the B. Okay, Well, what's gonna happen, guys? Is that the electrons from my sodium borrow hydride with the CN group, this H can attack the carbon eel and push electrons up to the end. Okay, so we're gonna basically do is we're gonna take one of these. H is we're gonna take that red h. We're gonna attach it to the bottom of the mini, um, cat ion. Then we're gonna push the electrons up to the nitrogen. So what that means is that. Now I'm gonna have to new electrons here that becomes the lone pair on the nitrogen. And we have the extra red hydrogen that is now there. That red hydrogen came from the basically inactivated version of my sodium borough hydrated. Because once again, I said that the C N is electron withdrawing groups, so kind of in activates the reducing agent. Okay, so that's really it. Now we have a primary amine. All right, so for this next question, I want you guys to take this molecules. You can see it. It's a key tone. So go ahead and react it with these two re agents. Try to predict what the product's gonna be, and then I'll go ahead and explain the whole reaction to you, so go for it.

alright guys, you might not have noticed, but this is one of the most famous applications of reductive am a nation. This is the Walter White special. This is how he made his million's, remember that he didn't want to be making meth from pseudoephedrine anymore. And he was looking for a more efficient type of cook and remember that he really needed to find methyl amine. Methyl amine was his limiting re agent. Well, that's because he needed to do a reductive am a nation of methyl amine as a source of a mean, which is a primary amine with fennel acetone, which is a precursor for methamphetamine. Alright, so then all we need is methyl amine atop in an acidic environment. And then we need a mild reducing agent, um such as our sodium borough hydrated with the Sino group that would work perfectly now. He might have used some kind of h two gas with a catalyst. Whatever. As long as you have some kind of mild reducing agent, you can reduce the Emini, um, cat ion to the amines. So let's go ahead and draw both steps. I'm not going to draw the whole mechanism for for the Emmy in part because once again, you can just watch that video. But let's make the A mini, um, cat ion. Remember that the, um, any, um, cat ion would be the carbon eel. But now, instead of an O, it has a nitrogen. The nitrogen has a plus charge. That means that it has four bonds. Right? So we're gonna have, um ah, hydrogen, and we're gonna have a metal group. Where that metal group comes from is that's the methyl group that was attached to the methyl amine. Okay, so now we use are reducing agent and in this case, and we're gonna use our sodium borrow hydride with the CN group. Okay? What that's going to do as I showed you guys in the mechanism earlier is that's gonna add an age to the bottom. Here, kick electrons up to the nitrogen. Let's draw the product underneath three agents. The final product is gonna look like this. It's gonna be a benzene ring with a nitrogen here, a methyl group here, a carbon there, and h here. And guys, you know the name of this product. Hopefully you're not too familiar with it because it's terrible and disgusting drug. But meth Amphetamine, right? Crazy. Right. So, guys, before you go ahead, start getting all excited that you can run this cook yourself, please be advised that you're gonna run into major problems with the D A. As methyl amine is a controlled substance, fennel. Acetone is a controlled substance. So you're gonna need toe start synthesizing from much smaller molecules before you start doing this on your own. But I think it's a really fascinating and interesting application of reductive lamination. And it shows you how, uh, you know, our organic chemistry can apply to our riel world. Okay, so that being said, let's move on to the next video.