Wednesday, September 16, 2009

sweet, sweet buzzwords

I saw this beauty this morning while having my morning tea, and it just cements in my mind how badly people want to latch onto popular, and often useless, nomenclature. Perhaps the best example of worthless jargon that is used frequently is "chemoselective" which appears to have no proper definition, and adds nothing to the chemist's lexicon that wasn't already available, but a close second these days seems to be "organocatalytic".

David MacMillan appears to be a great chemist, and an ok guy, but the real fame in his chosen area seems to be based largely on sales tactics. His classic contributions to the area are merely improvements on existing methods. Is that bad? Of course not, but now everyone else wants in on the game.

I think it's a bit odd to call most of these things "organo" catalized reactions anyway, because the active centers typically are nitrogen. Anchimeric assistance is often provided by oxygen or other nitrogens, and the hydrocarbon organic portion is typically scaffolding, as in many inorganocatalized reactions.

In today's example the authors most likely wanted to add some pizazz to their paper with needless, and inappropriate, jargon. It's too bad, really, because the method is actually quite nice, and doesn't need the added tripe. While the title proudly claims the method is organocatalytic, the graphical abstract has a nice large fluorine cation, and no carbon to be seen.

The fact that it says salts in the title should be a giveaway, but it never hurts to look on a bit further. The first depiction of the catalyst is given in scheme 2, where we see it's N-fluoropyridinium
triflate. That's like calling a reduction with tetrabutylammonium borohydride organostoichiometric.

Some very quick math shows that the hydrocarbon portion of the salt is only 31.2% of the mass of the compound, and that the inorganic active fluorine is just below that at 30.8%. To really beat this dead horse lets look at a heavily skewed example of a common inorganic catalyst, tetrakis(triphenylphosphine)palladium. This common catalyst and catalyst precursor has more than 10 times the hydrocarbon mass per mole and the portion of the catalyst that is hydrocarbon is over 80%, that's even better than the carbon rich MacMillan catalyst (5S)-(−)-2,2,3-trimethyl-5-benzyl-4-imidazolidinone monohydrochloride at 69% hydrocarbon.

Suffice to say I wish people's chemistry would stand on its own two feet but it seems everyone knows that massaging the system works better, and if someone else has laid the groundwork why not capitalize on it.


Jim said...

Don't believe the hype.

Its not about what my chemistry can do, but what I can make you think it can do that matters anymore.

scientist 1 said...

Unfortunately it's not "anymore". Chemistry has had this problem for quite some time, and other fields too, I would imagine.

Mike said...

Feedstocks! The atom/step/redox economy!