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Topic: Unreactive acetate in Tsuji-Trost  (Read 4247 times)

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Offline Neecze

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Unreactive acetate in Tsuji-Trost
« on: January 12, 2011, 03:48:23 PM »
I try to do intramolecular allylic substitution (Tsuji-Trost) of malonamide containing also allylic acetate moiety (-CH(OAc)-CH=CH2). But allylic acetate seems to be unreactive towards palladium catalyst. I tried many conditions (including application of electron-rich phosphines as TTMPP), but never got traces of product. I think allylpalladium complex is not formed in this case.

What's going on? Can allylic acetates behave in such way?

Offline MissPhosgene

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Re: Unreactive acetate in Tsuji-Trost
« Reply #1 on: January 12, 2011, 04:04:30 PM »
You could potentially be adding the acetate back instead of the desired nucleophile. Have you tried using the desired nucleophile in a slight excess with ligands which are not so electron rich? The problem could be a structural one, in which the reaction simply does not occur well in the intramolecular fashion you desire. The metal should bring everything together... maybe groups cannot align in the proper geometries for reaction to occur so nothing happens. 

Can you provide structures?
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Offline g-bones

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Re: Unreactive acetate in Tsuji-Trost
« Reply #2 on: January 13, 2011, 04:13:14 AM »
Is it possible for you to create the carbonate instead of the acetate?  these are much more reactive substrates for Tsuji-Trost chemistry due to entropic driving force in the loss of CO2. 

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