Carbon-Based Iodidiocies
January 25th, 2010 by LiqCThere’s a cool little paper in ACIE about making iodocarbonates from allylic and propargylic alcohols and iodine under CO2 atmosphere, iodolactonization style. Well, I thought it was iodolactonization style, but they draw an actual iodine carbonate (IOCOR) as an intermediate, rather than an iodonium. Regardless of the mechanism, I think that any reaction that utilizes as reagents gases more commonly viewed as supplies is pretty cool.[1] Bent alkyne — NOT cool.
I think you can even run it by simply throwing dry ice and iodine in a THF solution of your alcohol. Don’t worry about the oil, seems like you’ll need chromatography anyway. Simple reaction that provides nicely functionalized, differentially protected compounds. What caught my eye though was their emphasis on chemical fixation of carbon dioxide. Erm… Let’s do the math for scale up.
We’ll need carbon dioxide (8.4 Gt, 190.9 Tmol — total emissions in 2006), tert-butyl hypochlorite (2 equiv), sodium iodide (57.3 Gt, 1 equiv), THF (1140 km3).
See what I mean? How can one be serious about industrial scale chemical fixation of carbon dioxide? Even if it’s quicklime? What do you guys think about the whole atmospheric carbon issue?
On a related carbon-based note, I read up on nanotubes.[2] More carbon-based than carbon dioxide, CNTs have made a quick appearance here at CBC before. Nowadays, it seems like we know how to produce them efficiently and selectively (single-walled over multi-walled, for instance). Here’s an incredibly cool picture from this Science article, which illustrates a striking process of transforming an unappealing black powder into a very unusual material.
[1] The professor from that lab knew a student who came to try to activate nitrogen. Specifically, he intended to revert a Schiemann reaction. He claimed that he had isolated phenyldiazonium tetrafluoroborate in low yield from PhF+BF3 reaction, run in liquid nitrogen.
[2] NOT an online video sharing website for really tiny internet junkies.
Ooh, that CNT paper is pretty science. I likes it. Who knows, maybe it it even inspired that bent alkyne?
A friend of mine did a departmental seminar on the feasibility of using carbonate minerals a few years ago. You could make a pretty decent mountain in short order trying to sequester major emissions; that seemed about the only thing this would be good for.
diazonium by insertion into N2 is obviously crap (if not for other reason that PheF would freeze out from liquid N2, and solubility of most organic compounds in liq N2 is zero). But uncomplexed BF3 is extremely hot stuff. Complexation of free BF3 can serve as a thermodynamic sink for lots of weird reactions.
This reminds me how Meerwein triethyl oxonium salt Et3O+ BF4- was discovered: When you dissolve epichlorohydrine in dry ether and add BF3 etherate, the triethyl oxonium salt crashes out. I have done it on a half-mol scale and it is a very pleasant procedure if you can keep the moisture out during the filtration.
This paper summarizes my feelings on atmospheric CO2:
Journal of American Physicians and Surgeons (2007) 12, 79-90
How good are the yields on those carbon nanotubes? Had a guest speaker here at university saying that anytime his lab created nanotubes and attempted to assemble them for the purpose of electrical conduction, they always ended up with a fair amount of “soot”.
http://www.jpands.org/vol12no3/robinson600.pdf
I like that they’re discussing “urban heat island effect”—totally true. It has become common for the snow to completely melt several times throught the Moscow winter (at 56°N, ways away from any major body of water!)
On one hand, better to be safe than sorry. If restrictions to conventional fuel (which we are running out of, among other things) go over the top, it’s not good. But if it leads to faster development of better energy sources—yay. Solar power is the way to go, if you ask me.
That article under “single-walled over multi-walled” claims preparation of high quality SWNTs, “free from amorphous carbon and metal particles”. Purity is really important, as much as in semiconductor compounds. If 0.1% of your nanotube is not carbon, soot if effectively what you have, as far as I understand.
Silly rabbit – a few $billion in grant funding might make the reaction catalytic in hypoiodite using solar energy. Carbon credits would pay for it all at no cost to consumers. The secret hides within Grandma Bullwinkle’s mooseberry fudge cake.
And what pedagogic good is it at all if it is not enantioselective?
better than Copper nanotubes thats for sure.
OMFG! I’m joining it. http://www.facebook.com/group.php?gid=6130173005
I HATE bent alkynes. Nice post! The sequestration justification for the research needs more support, for sure, but it will be awesome when one of these days someone hits upon a simpler reaction that takes in CO2 & poops out a useful building block for something.
Nothing is produced on such a scale to be viable to be used to chemically alter carbon dioxide. Carbonated sulfuric acid, anyone?
I do not know what to think about CO2. The recent revelations that reports of glaciers melting by mid century were deliberate lies for political purposes, and the fact that some of the ‘peer reviewed’ science in IPCC reports were written by WWF activists and had never been vetted at all, and the scandals that are deepening around ‘climategate’ to the point that hardcore AGW promoting scientists are calling for the head of the leader of the Hadley makes it all stink to high heaven.
Nobody hides good data. You don’t cheat when you are winning. And you cannot, cannot, cannot lie about data and models and be a scientist. I’m beginning to feel sorry for people who have been called denialists. The science may be on the right track, or not, but it is goddammed well not ’settled’, and squelching dissent just because you dislike the politics of the dissenter is bullshit.
Oh, and I met the guy (Ray Baughman) at UT Dallas who is leading a lot of the nanotube materials stuff, including the Science paper above. Very neat guy. We had a DARPA grant that he was involved in when I was a postdoc.
Mike North at Newcastle in the UK has similar chemistry based on salen complexes using epoxides rather than allyic acohols and a stoichiometric oxidant
http://www.staff.ncl.ac.uk/michael.north/
They even have a flow reactor that they plan to use in power station towers which is pretty cool.
Fun cyclic carbonate fact: ethylene carbonate melts AND boils at higher temps than propylene carbonate…
Here is another report of a CO2 fixing reaction. But this one works in air, forms oxalate, and also shows how the key CO2 fixing species can be recycled at high energy efficiency (so it could be catalytic and not stoichiometric in the reductant).
The problem is that it goes really really slowly.
http://www.sciencemag.org/cgi/content/full/327/5963/313
Didn’t make it too fast to Science either.
But I love it. There’s a fair deal of serendipity. We mess around with Cu(I) a lot here. We’d never even considered that when it turns blue, it’s not always oxygen that’s responsible.
That bent alkyne looks WEIRD! Is that just a retardo drawing, or are some alkynes naturally bendy for some reason? Forgive the n00b question
In this case – the former. Cyclic alkynes are bent and unhappy: http://pubs.acs.org/doi/abs/10.1021/ja803086r
You need at least 8 carbons for a stable cycloalkyne.
Ψ*Ψ and I were both in the same alkynocentric research group, though we did not overlap. I would like to know what bossman would say to the bendy alkyne.
Despite my rant above, I really think the CO2 fixation reaction is pretty fascinating. Anyone know what the theoretical max rate is for plants (biological plants)? I would imagine evolution has done a good job with this, and it would be interesting to know how much of (say) a coal power plant’s emission one could fix if one was as good as nature.
http://en.wikipedia.org/wiki/Photosynthetic_efficiency