Amines by Reduction - Video Tutorials & Practice Problems
On a tight schedule?
Get a 10 bullets summary of the topic
1
concept
The Primary Amines Flowchart
Video duration:
9m
Play a video:
Hey, guys. One of the most common ways that you can make a means is through the reduction of more highly oxidized nitrogen compounds. There's actually a ton of these reactions. So what I'm doing in this video is I'm grouping together a bunch of similar reductions that all generate primary means so that you can have, like, a cheat sheet of similar related reductions that all lead to the same type of product. Now, as a disclaimer. Keep in mind that your professor may not need you to know all of these right now, but I'm banking on the fact that at some point in this course, you're gonna see all these reactions in different places. So I'm grouping them together for use that you'll think of them as similar reactions that are related to each other. Okay, so let's start off with a means by reduction. So, as you can see, I've got a lot of arrows here. There's six main reductions that we're going to consider to be related. They all lead to the same product, which is a primary amine. Okay, now, before we get into the specific reactions, I want to talk about something. I'm calling the common reducing agents. Now, this is not a term you're going to see in your textbook, but just through, you know, kind of looking at all these reactions. I noticed that there are some reducing agents that are used more often than others. And the ones that are the most common are lithium aluminum hydride, which is your strong, typical strong reducing agent, Um h two and palladium catalysts. That would just be catalytic hydrogenation. Obviously, you could also use nickel or platinum for that, and then finally, iron in HCL, which is also pretty commonly used. Okay, I'm gonna refer. These is the com introducing agents, and I'm just going to generalize them as h in brackets. Now, agent brackets always just stands for reduction in general. So I'm just gonna say, if I write in ancient brackets, that means all three of these reactions count as a reduction that would work here. Okay, so let's go ahead and start off on the left side of my chart, and then we'll kind of move to the right side and we're gonna find is that the first few re agents are just straight common reducing agents all the way. So if you want to turn and amad into a primary mean, guess what free agents you use. You're gonna use your common reducing agents. That means you could use lithium hydride. You could use catalytic hydrogenation. You could use iron and HCL. It's up to you. All of them work. Okay, Pretty easy. So far, let's go on to the next one night trial. How? Whatever. I want to turn a night trial to a primary amine. The common reducing agents. Awesome. So once again, it's the same three re agents. The same three agents can work with a night trial toe. Add hydrogen is to that triple bond, by the way, it is gonna be two equivalent. That is kind of interesting. So that means whatever you're reacting with is gonna work twice. Since there's a triple bond, you have to get rid of both of those pi bonds and you wind up getting your primary mean bueno. Okay, let's keep going. So, what do you guys think about nitro groups? A nitro group can turn into a primary mean using the common reducing agents. Awesome. Okay, so this chart is seeming pretty easy, actually, because we're using the same reagents for all of these you can use again. The three re agents that we talked about would all work. But actually, Nitro is special guys because I have discussed this in the past, or I do have other videos talking about the reduction of nitro groups. And maybe you guys might recall. Or maybe you haven't heard of yet that there's a chemo selective reducing agent that really just focuses in on the nitro group and doesn't reduce any groups around it. Okay, maybe you guys remember it. Maybe you don't. I'm gonna right here. Which one's the chemo? Selective one. What? Turns out that there's another reducing agent that you can use on Nitro. That's probably the ideal one to use. And that's what we called tin to chloride. It's S N C l two and water. Okay, this is also known as I'm just gonna write it in a different color. There's also known as Stannis chloride. Okay, Stannis chloride, or tin to chloride. Whatever. They're all different ways of saying it. But anyway, Stannis chloride tin to chloride s N c. L. Two over water. What that's going to do is it's a very special region because it on Lee works on nitro groups. It doesn't reduce anything else. Which means that we don't have to worry about protecting other vulnerable groups. Toe reduction. It's on Lee in a react with no too. Which was why we call it chemo. Selective. Awesome. So let's move on to the other side. So, guys, the other side is going to get more complicated as a heads up. Okay, So if I want to turn aside and aside is a functional group with N W one n one n. Okay, It's got some formal charges in there, but they balance out, so there's no net charge. Okay, Now for a side, we're not gonna able to use the common reducing agents. We're gonna use another region instead. And that is a try Fennel foss fiends. So ph three p. And water. Okay. And what this is going to do is it's going toe work consecutively on those nitrogen thio. Basically, it's going to release two of them, and you're going to just get a primary mean Okay, So what about the next one? Well, I have a question for you. Maybe you guys can integrate some other stuff we've talked about before. What do you think about my common reducing agents here If I took Carbonneau? This is in this case, this is an alga hide. Right? So if I took an alga hide and I used one of the three, um, com introducing agents on this, what I get in the mean What do you think? No, guys, if you use, for example, lithium, aluminum hydride LH If you use that on my album, hide, you're gonna get an alcohol you're not gonna get into mean. So how do I turn a carbon Neil without a nitrogen group on it? How do I turn that into a primary mean? Well, guys, for this, you could only use one solution. One of my favorite reactions. This is gonna be reductive. Am a nation reductive am. A nation is going to turn ah, carbon Neil into a primary amine. So the re agents for reductive am a nation are gonna be some source of nitrogen. So I'm just gonna put NH three. But it could be any source of nitrogen. That's either metal not methods zero degree or primary degree. Um, some kind of acid. So I'm just gonna put your age. Plus, so it's always gonna be in an acidic environment, and then you're gonna use in the second step, you're gonna use a reducing agent that has a scion. Oh, group in it. So it's n a b h three c n. Okay, so what you wind up doing is, um, in the first part, it's gonna be kind of like an amine reaction, like making an amine. And the second part is a reduction that takes the mean and makes it into a carbon. Neil. Now, guys, I do have separate videos for some of these reactions. So, for example, reductive emanation. If you wanna know more about the mechanism, you can just type in reductive elimination into the search bar, and then you'll find ah, whole video. Just about that one reaction. Remember, this is just a cheat sheet, so I'm not gonna be really go through any mechanisms on this sheet. Okay? Now, So hopefully you know, that would make sense. You guys know you need to learn that one. What else? How about if you want to turn in a sealed as I into a primary mean? Well, guys, this one's a little more complicated again. We're not gonna use the typical common introducing agents. This is gonna be ah, very famous reaction called the Curtis three arrangement. Okay, again. Very important reaction. You may need to know it now. You may not need to know it now, but I will. There is a separate Ah, whole separate lesson just on this one reaction. It's very It's very strange mechanism. And the re agents for a courteous rearrangement are just gonna be two things. It's just gonna be heat and water. Pretty straightforward. Okay, so heat and water, as you can see, it's like, how does this thing turn into a primary mean? Well, eventually, what winds up happening, guys, is that you've got your our group here. So what's your are Okay? And if you get your nitrogen here and eventually you wind up making a bond between those two. So I know it was kind of in the way for that, But what I'm trying to say is that these two carbons here wind up attaching to the one single nitrogen that remains here. And you wind up getting there. You go. Your primary me Because you got your two carbons. It could have been as many carbons as I wanted, but on this structure is too. Plus, the nitrogen gives us a primary mean again not going over mechanisms here. But you could search the critics rearrangement, and then I'll explain that whole reaction in detail. All right, so now we're done with all of the means by reduction, these air, all the reactions that I consider similar because they all yield the same exact products. Okay, now what I'm gonna do in the next video, I'm gonna talk about some related reactions that might help us make the initial starting products. Let's move on to the next video.
2
concept
Making Amine Precursors
Video duration:
3m
Play a video:
now, guys, the reason for this part of the video is because I talked about two carbon Neil precursors to Inamine. One was an amad, and the other was the A C L. As I. And it turns out that both of them have a common like parents structure. And that's carb oxalic acid right here. So this section is just to serve as a reminder of some of the carb oxalic acid conversions that will be in the carb oxalic acid derivative part of your texts. Okay, so this is just again kind of a cheat sheet of how you could use carb oxalic acid to make thes two initial structure that then you could reduce to Inamine. Okay, so let's say that you wanted to make you're starting off with karmic selic acid and you wanted to make a amad. Okay, well, that's pretty straightforward. All you have to use is NH three. Okay, if you react NH three with your car. Looks like acid. You could make an amad now, um, some text some professors may want you to throw in some D c. C in their d. C. C. Is a dehydration agent that helps the yield to be stronger or better yield. So regardless, it's not a huge component of the reaction. NH three will eventually work. If you throw in some D c c, it's gonna work faster. Okay, Awesome. So that was easy. That's how we get to Anam it. How do we get to an A C L as I'd Well, there's actually no way to go straight from Karl oxalic acid to ASIO as I'd. What we can do is we could use eso seal too, to convert our car. Looks like acid into an acid chloride. Okay, now remember that there are some other re agents for this or you could use PCL three or you could use P C. L five. All these regions really do the same thing they add. They replace and always group with cl so you could get your acid chloride from there. Now, this is just gonna be a simple nuclear feel. Like a seal substitution. You could just use n three negative. Okay, You could use n three negative thio, basically, dio, you know, substitution reaction on the chlorine and get your n three where the chlorine was. And that's your eso as I And then you could plug that into my cheat sheet and you could say Okay, well, what would that make if I added heat in water? You know, that would be a courteous rearrangement. You would get a primary mean. Alright, Awesome. And then just just, um, two more conversions that I want to show you, which is that acid chloride doesn't just goto eso as I You could also make it Macon amad just by using an h three. Okay, by the way, this one you definitely wouldn't need DCC with because the yield would be so high. You don't need a dehydration agent. And also in anhydride, which is a related functional group. Um, if you want to start with from anhydride, you could also just use an H three, which could, which would make your am I so the only one that you really usually have to use a dehydration agent on would be your carb oxalic acid itself. Okay, awesome guys. So that was just a little refresher of how to make some related structures that then you could later reduce using the re agents that we talked about. All right. So hope that made sense. I hope this chart is helpful for you in a section that has a lot of random seeming reactions. So let's move on to the next video.
Do you want more practice?
We have more practice problems on Amines by Reduction