Thiols are more acidic than their oxygen-containing analogs, alcohols. Therefore, acid-base reactions will highly influence their reactivity, with the formation of a thiolate anion usually being the first step.
The mechanism of Sulfide Synthesis.
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Now we're going to discuss reactions of files. And if you guys remember, files are the sulfur analog of alcohols, meaning that they look exactly like alcohol's, except the oxygen is replaced for a sulfur. How is that gonna change the molecules that gonna react just like an alcohol? Let's find out. So files are more acidic than a typical alcohol. If you guys think about it, that's to do with the fact that sulfur is low. It bigger in size and the size effect said that as the bigger the molecules get, the easier it is to give up H and get a loan pair. Okay, so files were gonna contain a very acidic hydrogen. Okay, so what that means is that it's gonna be easy to pull off that hydrogen and easy to make it a nuclear file after it's exposed to base. Okay, so after you expose its a base, pull off the hydrogen is gonna be a great nuclear file. Just so you guys know that nuclear file when the sulfur, as a negative charge on it is called a finally okay, so or violate nuclear file is gonna be capable of performing a few different reactions. That's we want to go over right now so we can do sulfide synthesis through a style. And we can also do die sulfide synthesis. Let's start off with the easier one, which is sulfide synthesis. So, in sulfide synthesis, I start off with my file, right? That looks just like an alcohol. Except it's got the s right, and I wrecked it with base. Okay, The base is gonna dip protein ate the H and make my violate. And I am then that Kylie and Iron performs an s and two reaction on alcohol. Hey, lied and calculates. Okay, so we wind up getting it a sulfide, basically the analog toe, either just with a s instead of oh, for the ether. Okay, let's go ahead and look at how this this full mechanism, Let's draw it out and make sure they're all on the same page. So my first step, my base is going to grab the acidic hydrogen of my Thile. Obviously, the hydrogen doesn't one of two bonds, so I make up on a break upon and I wind up getting What is this? Called my negative charge on my s. This is my thigh late and I am cool. So I got my file a an ion. Now, what can that do when exposed to an alcohol? Hey, lied. Well, if it's exposed to the right type of alcohol Hey, lied. I'm gonna be able to do and sn two. Okay, Now what? I mean by right type. Well, obviously this is a tertiary ocular. Hey, lied. Would that be ableto work? No, Because remember that tertiary alcohol lights cannot perform, in essence to reaction. But in most cases, if its primary or secondary it's gonna work. Okay, So I'm just gonna add here that this would have to be a primary or secondary alcohol. Hey, lied. Okay, so now I've got my backside attack my s and two reaction and what I'm gonna get as my product, it's simply a sulfur with now, whatever that our group was. Okay. Now, whatever, that our group, it could be Whatever I wanted, I just pick the ocular. Hey, light of choice. Cool. So that's how we make a sulfide out of a file. Not bad at all, right?
The mechanism of Disulfide Synthesis.
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Now let's talk about die sulfides I sulfides or a little bit more tricky. So notice that once again, I'm starting off with a file which looks a lot like an alcohol. If that had been in Oh, that would be methanol. Right? So this is method file, because it's a s h. OK, so I got my meth. My I've got my file. I've got my base again. So notice that the first step is gonna be exactly the same. My first step is gonna be a base reacting with my file to take off the age. The weird thing is that then I've got this hallucination thing going on in this beer two. Okay, so let me explain how that works just through the mechanism. Okay, so let's go down to the dye sulfide synthesis mechanism we're gonna find Is that the first step everyone should be able to draw? Okay, you're Ohh grabs the acidic hydrogen and you wind up getting this this very familiar intermediate. What is this called? This is my thigh late. Okay, so now I've got that violate now exposed that toe a die atomic halogen. And this is interesting. The diatonic halogen is going to be able to be attacked. Okay, so my sulfur will grab one of the BRS kicked the other one out. What I wind up getting is something It looks like this where I've got sulfur br okay. And then I've got a br negative just hanging out. Cool. So far. Awesome. So now here's the interesting thing. Okay. Not only am I gonna make one violate, but I could I could make several violates okay? Because I'm gonna excess base. So it's gonna basically D protein ate all of that. All most of those hydrogen. Okay, So what happens in the next step is we're just gonna go ahead and bring this down over here, okay? And what we're gonna find out is that a second silence. This would be my times to This is my second violate. Can actually do a backside attack on this sulfur. Okay. And it would kick out believing group. So you're gonna wind up getting at the end of this is a dye sulfide where you have S s and then a symmetrical die sulfide. Okay, you have a die sulfide product, okay? And that the guy sulfide would be symmetrical because the fact that you're going to use the same violate twice, Right. Okay, so you die sulfide, and you just get even more be are leaving group. Okay, so it doesn't really matter. We're not. We're not paying attention to the BR. We're really paying attention to the organic product, which is our die sulfide. Cool. So none of these reactions air hard. I know we're not used to dealing a lot with sulfur, but it's really not that tricky. Okay, so I hope that made sense. Those were the two really common reactions that files undergo. And if you have any questions, let me know. But if not, let's move on.