Latest piece for the RSC in Chemistry World.
This is cool, I’ve always been fond of tethering… on paper.
How is that a strained silacycle though?
Silicon when flanked by heteroatom(s) is strained in a five membered ring because the bond lengths with Si are longer. Typical bond angle around the Si-pseudoephedrine reagent is about 95 deg. This induces the silicon to become electrophilic so it may become pentacoordinate upon coordination of aldehydes, keteones, etc.
For more examples, see: http://dx.doi.org/10.1021/ja0264908
By the way, have you guys read the new Tamiflu(TM) paper in Angewandte? Truly interesting to see the Roche scientists dismiss the myths that (to paraphrase them) ‘azide chemistry cannot be effected on production scale’ and that ‘shikimic acid is a scare resource’. That was a truly interesting read, and a very neat route that takes advantage of the slightly higher reactivity of the allylic mesylate! After that, everything follows so smoothly! Shorter than their original route, and the yields can only get better once the process group gets a hold of it… Neat!
Very nice response to the azidophobes!
Triethyl phosphite is fine, by tributylphosphine on ton scale still gives me creeps.
Oh, and my apologies for this early thread-hijacking!
I am pretty sure that this type of allylation was pioneered by Leighton.
Correct. That citation got dropped as only so many can be crammed into the magazine pages…
haplophytine is finally up in ACIEE
i am not all too impressed at the synthesis, and am confident a more elegant Haplophytine synthesis will be up in no time.
ha, really? big words. this is the suicide molecule that corey couldn’t finish. this thing is truly a beast.
i’m more impressed that fukuyama and co. finished it with “relatively” simple/classical reactions.
Haplophytine was one of the great remaining unconquered targets, with a rich history and a beautiful, formidable structure that has frustrated organic chemists for decades. Congratulations to Fukuyama and coworkers for being the first to synthesize this monster.
Is it not just taking the advantage of KCN’s route for the left half….
so the real credit to KCN..!
It’s unlikely that any ‘copying’ or whatever happend – they published similar routes in the same year, using similar biosynthetic principles. This kinda ‘duplication’ happens all the time.