it takes some serious talent to screw this up
I will never really understand why people bother to buy tetrakis(triphenylphosphine) palladium(0). On any given day, it's definitely the easiest reaction I do, and it always works. On a bad day, the bright yellow crystals are enough to make me feel a little better. (Also, palladium catalysis is MAGIC.) Apparently, it doesn't ship well and might show up in funny colors (unless maybe you get it from Strem). It only takes about half an hour.
Excimer asked me a long time ago to post the procedure I use to make this, and I'm finally getting around to it. One of my labmates googled this a while back, and it's never failed us. It also has the advantage of being free. Usually I work on about a hundredth of their scale, which still works well enough--I'll maybe never have an excuse to make over 100 grams of the stuff.
Store under nitrogen and in the dark--it's ready for whatever coupling reaction you want to throw it into. (This batch is going toward a Sonogashira and a Stille.)
19 comments:
I see that your tetrakis procedure is from a good source, Rhodium of the Hive fame. Here is another one:
http://opioids.com/fentanyl/synthesis.html
Hmmmm. I never paid too much attention to the source--there were references, my labmates said it looked pretty much right, so I adopted it.
I'd still rather just buy the shit from Strem. Laziness, or efficiency (why run a reaction when you can buy it and, like, read a paper or ten instead)? I'm not telling.
(laziness. duh.)
Palladium catalysts are magic. But one reason to make your own is that the magic can die (ask bossman about the mysterious refusal of all of our Pd catalyst to work for weeks, way back in the time of "the littlest Chow"). I dunno if we ever figured that out. I know I found a charmed bottle and hid it from a particularly obnoxious (though likeable) labmate.
OTOH, I don't buy Ni catalysts, either, though I've never had one crap out. I just like making the occasional compound where you stir, filter, and voila'.
I cannot bring in hydrazine hydrate. ;<
Great post. You're right, tetrakis is dirt simple to make. I've made it plenty of times. My challenge is to weigh the activation energy of getting a student to make it the first time vs. getting the experiment done. In my case they would have had to order PdCl2 as we are out of it and then carry out the reaction. So, kinetic selectivity favored buying it. :)
Like taitauwai:
Hydrazine hydrate is a suspected carcinogen and I have to fill in 43 forms in order to be allowed to use it. So, I just buy the Tertrakis (Yeah I know... stupid industry out here).
And why doesn't your tetrakis turn brown in a day or 2?
Mitch
Inorganikers need a whole Periodic Table to either 1) Mix then filter, or 2) melt together and "95% isolated yield." Organikers can fill a waste crock with tar while never topping 0 C. One p-block element! (plus co-conspirators)
Make Cp2-superphane and stack with Fe(II) into infinite linear chains. Add PEG legs on the bridges to solubilize the crud into a lyophilic liquid crystal. Publish claiming eventual self-ordering quantum computation modules (redox!), turn off the lights, go home.
I once made 30 g of the stuff and then put 1 g each in 30 little vials under nitrogen. Then into the freezer. I went away for a sabbatical and when I came back, I swear there were 30 different colors in those vials everything from yellow to orange to green. I have since taken to mixing Pd-dba with TPP (or TFP) in THF and in 5-10 minutes I am ready to go.
David, I like nickel catalysts. Ni(dppe)Cl2 is a very pretty red and like less than half the price of most Pd catalysts. I enjoy using them.
An off-topic comment. Thought you might like to know that I linked CBC in the latest Crapshoot (the first in a 3-part look at rotatable bonds). Also congratulations on your paper and CBC's first birthday.
Excimer- I am also a huge fan of Ni(dppe)Cl2. It is cheap, and it is falling-off-a-log easy to make.
I had the luxury in graduate school to work in two groups, one organic materials and one organometallic. Since my advisor was untenured at the time, I had to have a tenured co-advisor. I think in most cases at my alma mater, this is purely a formality, but my projects had enough overlap that I got to do some real organometallic work.
The pentacene stuff killed off some really neat projects and brought my organometallic work to an abrupt halt. I made some really nifty 1,2 disubstituted ferrocenes, really cool compounds by 2 different and interesting routes, that never made it into print, which is one of my only regrets from grad school. There was not an obvious heir to my work when I left, so it just sits, waiting for someone to love it...and to interpret my awful organometallic lab notebook (which is another regret...)
Huh? That's news to me, Dave...did you work for Selegue as well?
Yep. All he got out of me pub-wise was a weird Heterocycles paper on an unusual 10 membered ring that I made by accident. Too bad, because we had a quite a bit of steam going for a while.
The ferrocene and manganese chemistry was working really well when Bossman walked up and said "How would you like to try some acene chemistry." I figured he meant try something that one of the guys who recently graduated had abandoned. I figure it would crap out and the whole thing would die, because I figured the guys before me had beaten that stuff to death. Nope. I was constantly busy with something that was working well for the rest of the time I was in grad school. No complaints. Anything that gets you to escape velocity is fine with me. But I wish I had had another year or two. With a wife and son, that wasn't in the cards.
Another guy in Jack's group picked up the Mn stuff, and now he's a prof at WKU.
Ah. He was my academic advisor before they changed the system around completely (which is too bad, because he's pretty much awesome). Some of the projects he has (kinda) going right now are really cool, but there aren't enough people around to work on them.
Jack is fantastic. I think a lot of people don't get him, because he is so mild-mannered. But, right when you get lulled into thinking he is above the fray, all of a sudden he'll bust out some Zen Tai Chi of chemistry so profound it'll take weeks to absorb it. If you don't pay attention, it's gone.
The guy seems to have a near photographic memory for the lit, too. I can't say enough good about Jack.
The secret to Jack's success is the love of Mien Troong.
Is there any universal solvent system to get all heck catalysts to go into solution? I want to measure the Pd in them. How do I get them into solution without using aqua regia!
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