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Topic: Cleavage of benzylthioether.  (Read 4385 times)

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Offline OrganicDan96

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Cleavage of benzylthioether.
« on: June 01, 2018, 01:34:19 PM »
I want to cleave a benzylthioether to give a thiol, the most common conditions for this is by sodium in ammonia however the molecule contains an fmoc protected amine and this would probably be removed under these conditions. I know that you cannot use Pd/C H2 like for benzylethers as the the sulphur poisons the catalyst, so I am looking for relatively mild conditions for this transfomation. does anyone know of such conditions?

Offline phth

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Re: Cleavage of benzylthioether.
« Reply #1 on: June 02, 2018, 07:01:32 PM »
I think your best bet it to go the oxidative method: you oxidize the thioether and benzyl cation will fall off forming a disulfide. I wouldn't bet on there not being a set of hydrogenation conditions that will work, also...

http://pubs.rsc.org/en/Content/ArticleLanding/1991/C3/C39910000167#!divAbstract

Offline OrganicDan96

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Re: Cleavage of benzylthioether.
« Reply #2 on: June 07, 2018, 03:35:58 PM »
Thanks, after that oxidation wouldn't i need to cleave the disulfide to get back to the thiol?

Offline wildfyr

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Re: Cleavage of benzylthioether.
« Reply #3 on: June 07, 2018, 03:38:20 PM »
Yes, but a mild reagent like DTT should do the job without touching anything else.

Offline OrganicDan96

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Re: Cleavage of benzylthioether.
« Reply #4 on: June 08, 2018, 01:27:39 PM »
i hove found a method that uses zinc and ammonium formate, does this seem like a viable option?

Offline wildfyr

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Re: Cleavage of benzylthioether.
« Reply #5 on: June 08, 2018, 01:55:16 PM »
Depends on the rest of your molecule, but on its face, whatever works.

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