What I want to talk about now is a way that we can make triple bonds into strong nucleophiles. Now that might sound weird because if you remember, triple bonds are hydrocarbons, and usually hydrocarbons aren't really good nucleophiles or electrophiles. They kind of just sit there. But it turns out that triple bonds are uniquely acidic because of a principle that we talked about way back when we talked about acid and base chemistry. And we can use that to our advantage to make them strong nucleophiles. And these are called alkanines. So, let's go ahead and talk about how we can do that. So basically, remember that we talked about in the acid and base chapter. So if you didn't watch that chapter, it's fine. I'm just going to remind you now that terminal alkynes, the alkynes that have one hydrogen at the end, are uniquely acidic due to an effect called the hybridization effect.
Now when we talked about acids and bases, we talked about that there were basically 5 effects that made things more acidic. There were the element effect, inductive effect, resonance effect, solvation effect, and hybridization effect. I know this might be like, bringing back some bad memories for you guys, or maybe you just completely have no clue what I'm talking about. But hybridization was one of the things that could make something more acidic. And here's an example of a terminal alkyne right there. And let's just go through the, you know, go through the hybridization. Basically, what the principle said was that the more s character that an atom has, the more acidic it's going to be.
And notice that this carbon right here has what kind of hybridization? It has
Now just so you guys know, that's pretty high s character because for example
So how are we going to use this to our advantage? Well, it turns out that if we can use a strong enough base, we can pull off this hydrogen and give a negative charge to the terminal alkyne. Okay? So we're going to use a strong base to deprotonate like NaNH2, or sodium amide. And both of these are very strong small bases that are going to be able to pull that hydrogen off of the terminal alkyne. So I'm talking about that green hydrogen above me. Okay? So that's going to create a strong nucleophile that we're going to call a sodium alkynide. Okay? And what the sodium alkynide looks like is it's just going to be a negative charge on that triple bond.
So if I were to just erase some of this stuff and show you what the acid-base reaction would look like for this reaction, it would be that I have, let's say, NaH. Right? Well, that's going to dissociate. Right? That would dissociate into