A new precatalyst for Heck Reactions

It's a beauty, isn't it? I mean, look at that monster! And it packs 4 palladium atoms per catalyst too. It just appeared in Organometallics (DOI: 10.1021/om7005613). They actually coupled together iodobenzene and styrene. The cool thing about this is that they could tune the reactivity of the catalyst by changing the metal complexed in the middle of the porphyrin. With M=MnCl it took almost 400 minutes for the reaction to complete, but with M=Mg it only took about 200 minutes. Ok, seriously. I don't mean to pick on Bart M. J. M. Suijkerbuijk, Sara D. Herreras Martínez, Gerard van Koten, and Robertus J. M. Klein Gebbink, but I really don't understand what the purpose of this research is. I guess you can get some understanding about the electronic nature of pincer ligands, but no one in their right mind would ever use something like this for a Heck reaction. It is pretty though. It even weighs 10 times more than your substrate. I guess that makes for easy weighing. Let's say you use 10 mol% of the catalyst. You can just use the same mass as iodobenzene and you're good to go.

Busy as a bee

That is me and why I have not posted lately. I still plan to. Don't give up on me. I'm still finding a few minutes here and there to read an article or two. If only the days were 72 hours long. *sigh*

Anyway, there's lots of buzz about Apple's new Macbook Air. Lots of negative comments going around on the mac forums. I don't understand this. Sure, this computer is not for everyone. Sure, this computer could not replace a primary computer. But let's be honest. This is a computer for travelers. This computer is ideal for me. I can't wait to get my hands on one. In the last five years I can't think of a single time I have used my optical drive while on a trip. Rarely have I ever had to use an ethernet cable while on the road and in the last two years I have never needed an ethernet cable. Who's going to travel with bulky firewire peripherals in their carry on bag? All these arguments against the macbook air are ludicrous. Obviously made by people who don't go on frequent short trips. So I ordered one as soon as they were announced.

 I know this is a chemistry blog. So let's talk about chemistry. This is the first laptop with a mercury free LCD display. And the glass contains no arsenic.

methyl 7-chloro-6,7,8-trideoxy-6-(1-methyl-trans-4-propyl-L-2-pyrrolidinecarboxamido)-1-thio-L-threo-α-D-galacto-octopyranoside 2-(dihydrogen phosphat

Man, the name can't even fit in the title field! Maybe the structure will help. I caught me a nasty bug in my leg that's been growing ever since turkey day and this bad boy is trying to keep it in check. Unfortunately it doesn't look like it's doing a very effective job. I may need to get it in IV form. More and more antibiotic resistant bacteria are making an appearance. Get out there and discover some new drugs. Please! By the way, this one tastes like shit. I am pumped so full of it I can taste it oozing out into my mouth.

Hope you all had a better holiday.

Let's Talk Turkey

It is only a couple days away from the Thanksgiving holiday here in America. I love it. A whole day dedicated to stuffing a bird then stuffing yourself full of fats, carbs, and tryptophan. We get to laze around on the couch watching football and make serotonin out of that gobbler. Yes, eating turkey is thought to increase the amounts of this wonderful neurotransmitter and make you sleepy. Of course tryptophan is also the starting material for the production of melatonin, another inducer of drowsiness. Personally I think it is more likely that all the beer and wine being consumed is what leads to thanksgiving day couch potato syndrome. By the way, a recent study reported in the Journal of the Science of Food and Agriculture (that one is on everyone's daily reading list, no?) indicates that red wines have a significant amount of melatonin.

Gone but not forgotten

Albert I. Meyers
November 22, 1932 - October 23, 2007

I was deeply saddened to hear that Al has passed away. He has been an inspiration to me for a long time. A genuinely nice man, he always encouraged students and colleagues to fulfill their potential. I remember as a young graduate student giving my first talk at an ACS meeting how nervous I was. Afterward Al came up to introduce himself and tell me what a good job I had done. Thanks Al, that did more for my confidence than anything else in my career. Organic Chemistry lost a great one this week. Rest in peace, Al.

Happy Mole Day

Happy Holiday Everyone! I think we all need to take the day off and spread the good word about Avogadro. Is anyone else celebrating?

IBX (not Irritable Bowl Xyndrome)

I really like oxidation reactions but, for some reason, many students get confused about how they work. It's not really different than any other reaction. It's just electrons moving from one place to another. The problem is that we usually think it is weird to push electrons toward an oxygen at the same time break electrons off of an oxygen. However, in nearly every oxidation of alcohols, this is happening. Of course the requirement is that you have something attached to the oxygen that is more electrophilic. For example, highly oxidized Cr or S or, in the case of IBX or Dess Martin oxidations, I. Well, I saw this interesting paper in Angew. Chem. this week that used IBX to do an interesting double oxidation. It is a nice approach to the saxitoxin family of natural products. I thought I would share the mechanism for your edification. We don't often think about oxidizing past the ketone stage, but under enolization conditions and with the right structural features (beta nitrogen), you can oxidize the alpha carbon.

Iwamoto, O.; Koshino, H.; Hashizume, D.; Nagasawa, K., ACIEE, Early View

Al is the MAN!

From Senator, to Vice President, to President (well, he won the vote if not the chair in the Oval Office), to Oscar Winner, to Nobel Laureate. No one can say he hasn't accomplished something.

For his efforts in raising awareness about Man's influence on global climate change, Al shares the 2007 Nobel Peace Prize with the Intergovernmental Panel on Climate Change.

The 2007 Nobel Peace Prize

Well Done, Al. I think this prize is well deserved.


Why is this on a chemistry blog? I believe chemistry will be instrumental in solving problems associated with global warming. It already is - from new energy technology to new efficient materials, chemistry leads the way.

And the winner is . . .

Gerhardt Ertl for his work understanding the phenomenon of surface catalysis. In particular hydrogenation, CO2 reduction and more.



Read more about it here: 2007 Nobel Prize in Chemistry

Tetrakis Talk

{greg the chemist dialing the phone}

{ring}

AA: "Hello, this is Gregory from Alfa Aesar Technical Assistance. May I help you?"

GTC: "Yes, Hi. We have just received our order for 2 g of palladium tetrakis triphenylphospine. The shipment we received is sealed in an ampule but has a dark green color. Can we replace it with some good catalyst?"

AA: "Well, our palladium tetrakis comes in three different colors; yellow, green and brown."

GTC: "But this should be bright yellow."

AA: "We have analyzed our product and chemically it is the same. It should work fine for you."

GTC: "Palladium Tetrakis should be bright yellow."

AA: "I can see that you don't want our product. I will issue a refund and you can send it back to us."

GTC: "Um. Great. Thank you very much."

{click}

GTC: "What the hell? Three different colors? No thanks. Why didn't we order from Strem in the first place?"

{sorry for the poor photos}