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Articles tagged with: Suzuki

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[30 Oct 2011 | 38 Comments | 20,218 views]
Daphmanidin E

Carreira, Weiss. ACIEE, 2011, EarlyView. DOI: 10.1002/anie.201104681   
Now that’s a busy polycyclic ring-system!!  Three five-membered rings, two six-membered rings and one seven (depending, of course, on how one counts the ring sizes.  Anyone read the IUPAC Gold Book last night?) – adding up regardless of maths to one hell of a synthetic challenge.  And there’s even some token biological activity to aim for – this bad-boy has some moderate vasorelexant acitivity next to rat aorta.  (When the paper mentions ‘moderate’ activity, we can be pretty sure it does very little indeed…) …

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[4 May 2010 | 43 Comments | 18,247 views]
Complanadine A part I

Sarpong, Fischer. JACS, 2010, 132, 5926 DOI: 10.1021/ja101893b.
It’s quite hard to explain the phenomenon of simultaneous publication to people outside of chemistry, ’cause it simply isn’t easy to rationalise.  This is now twice in as many months, as Englerin A took my fancy in this month’s Chemistry World.  I’ve never been in the situation of working on a target with rival groups bearing down on me, but it must be quite punishing (I took the slightly easier option of working on a target that 1. had …

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[25 Feb 2010 | 30 Comments | 16,451 views]
Communesin F

Weinreb, Liu, Seo. ACIEE, 2010, EarlyView. DOI: 10.1002/anie.200906818.
Quite a congested little beast, eh?  I felt that a 3D representation might help show the almost cage-like structure.  Also, having been at a Med-Chem conference for the last few days, I’ve been seeing everything in 3D.  I haven’t seen many molecules with this skeleton before, so I was surprised to see that it was isolated in Penicillium mold; however, this was found growing on a marine algae, so I guess that makes for some pretty special biosynthetic machinery. …

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[20 Dec 2009 | 27 Comments | 14,578 views]
(iso)Bongkrekic Acid

Ley, Francais, Leyva, Etxebarria-Jardi. Org. Lett., 2009, ASAP. DOI: 10.1021/ol902676t.
For those UKian readers out there, there’s a fittingness to my posting a Cambridge paper following an Oxford last week.  Having spent a bit of time at both, it’s hard for me to pick a particular allegience, but I guess I have to go light blue, and congratulate the boys for their dug-in performance at Twickenham a few weeks back.  But I am particularly lucky to have been at both, as their approach to organic chemistry was so markedly different. …

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[17 Nov 2009 | 32 Comments | 15,338 views]
Fostriecin

McDonald, Robles. Org. Lett., 2009, ASAP. DOI: 10.1021/ol902365n.
It’s been a little while, but there’s been nothing too exciting (total synthesis-wise) in JACS or ACIEE.  However, a quick glance in Org. Lett. produced a veritable cornucopia of syntheses, with this lesson in catalysis nudging to the fore.
The target is a newbie to this website and to me too – but not to the chemical community at large.  Indeed, the list of prior syntheses is quite unnerving for the prospective student-synthesizer, including Kobayashi, Boger, Cossy, Shibasaki, Reddy…  This brings a certain amount of knowledge, …

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[17 Oct 2009 | 57 Comments | 22,284 views]
Platensimycin

Njarðarson , McGrath, Bartlett, Sittihan. ACIEE, 2009, EarlyView. DOI: 10.1002/anie.200903347.
It’s back!  Twice in as many weeks, too, as KC has decided to drop the details on his many syntheses of platensimycin and platensin into a full JACS paper.  However, I’ve spent enough time looking at his work in this area, so it’s a pleasure to examine this synthesis by Jon Njarðarson of Cornell.  I should point out that I don’t feel that this is necessarily the best route, but it’s got some damn smart chemistry in it, so what …

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[25 Aug 2009 | 8 Comments | 12,191 views]
Sorangicin A – pt. 2

Smith, Dong, Brenneman, Fox. JACS, 2009, ASAP. DOI: 10.1021/ja9052366.
Read the first post?  Good.  Let’s get on with the one remaining fragment, a further DHP.  Work on this fragment was conducted via a coupling of an enone with the ready-elaborated sidechain – reaction that might be a little sluggish, as the enol functionality is again working against the group.  However, forming a cuperate of the vinyl bromide solved this, allowing a highly selective and reasonably high yielding reaction (60%, 20:1 d.r.).  BTW, the two fragments weren’t particularly …

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[23 Aug 2009 | 5 Comments | 10,354 views]
Sorangicin A – pt. 1

Smith, Dong, Brenneman, Fox. JACS, 2009, ASAP. DOI: 10.1021/ja9052366.
I thought I’d re-start after holiday with a tasty target, and sorangicin A certainly fits the bill.  It’s not often that I have to draw such an exotic structural motif into a target (though in reality it’s not far removed from a DHP); always a welcome feature in a synthesis.  But sorangicin A is more than just a structural challenge – it’s quite an antibiotic, with broad-spectrum activity against both Gram-positive and Gram-negative strains.  With the funding proposal …

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[10 Aug 2009 | 36 Comments | 14,005 views]
Dioxepandehydrothyrsiferol

Jamison, Tanuwidjaja, Ng. JACS, 2009, ASAP. DOI: 10.1021/ja9052366.
Capitalising upon his pontifications analyses in Science (2007), Tim Jamison has come-up with the goods; a poly-epoxide cascade to build a poly-ether.  He’s not the only one – Frank McDonald crafted a nice synthesis last year using the same principles.  However, Jamison has upped the epoxide count, controlling formation of three ether rings in one go.
As ever, the initial trial is construction of the linear, poly-epoxy precursor – with few surprises in Jamison’s route.  The starting material is farnesol, …

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[28 Jun 2009 | 63 Comments | 40,884 views]
Himandrine

Movassaghi, Tjandra, Qi. JACS, 2009, ASAP. DOI: 10.1021/ja903790y.
Okay, I missed my ‘I’ll blog it by Saturday‘ deadline by a day, but it’s taken quite some time to get my head round these structures.  And beer.  However, I think I’ve got there – so ladies and gents – on with one of the best syntheses this year.
First up scheme-wise is a rather nice Suzuki coupling.  Taking a standard boronic acid, mixing in a vinyl-gem-dibromide, they achieved a selective E,E- product in cracking yield.  However, this came at …