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Topic: Electrophilic and Nucleophilic site(s)  (Read 5207 times)

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Offline rolnor

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Re: Electrophilic and Nucleophilic site(s)
« Reply #15 on: May 18, 2017, 06:32:53 AM »
To convert a furan to pyroll you need to open the ring and disrupt the aromatic system, this is possible in a furan because the aromaticity is weak, in a benzofuran the aromaticity is muck stronger.

Offline sun725

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Re: Electrophilic and Nucleophilic site(s)
« Reply #16 on: May 19, 2017, 02:28:16 PM »
This is the molecule I'm working with
http://imgur.com/a/dIDs4

I have to make a reaction with EVERY nucleophilic site on the molecule, and I want to know if this reaction is correct?
http://imgur.com/a/zESNg

My instructor is very sure about the ketone being nucleophilic, therefore I've to find a reaction here as well. Can the ketone here be acid catalyzed? Or is there steric hindrance?

I hope someone can help me with this. This assignment has to be handed in no time. I appreciate the *delete me* Thanks a lot.

Offline rolnor

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Re: Electrophilic and Nucleophilic site(s)
« Reply #17 on: May 19, 2017, 02:40:46 PM »
Its impossible to substitute the oxygen in benzofurane this way, its phenolic?

Offline sun725

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Re: Electrophilic and Nucleophilic site(s)
« Reply #18 on: May 21, 2017, 12:12:37 PM »
Well, I've looked through my textbook many times without finding anything unfortuneatly.

It should be in the aromatic heterocycle chapter, but if there is nothing specifically about benzofurans you can look at relatives like furan and indole to get an idea. What books do you have?


I have McMurry Organic Chemistry.
Can you please give me a convincing argument claiming the the ketone, or the carbonyl oxygen in the ketone is not nucleophilic. I really don't know what to write anymore. Everyone says something different. My instructor literally said that the Ketone oxygen can also be protonated, thus reacting it as nucleophile. My assignment is due and I want to write the right thing. So please, if you could clarify this. Thanks   

Offline Dan

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Re: Electrophilic and Nucleophilic site(s)
« Reply #19 on: May 22, 2017, 02:05:39 AM »
I really don't know what to write anymore. Everyone says something different. My instructor literally said that the Ketone oxygen can also be protonated, thus reacting it as nucleophile.

OK, I suppose you could make that argument. The issue here is that nucleophilicity is a scale, so when a question asks to identify the nucleophiles, I guess most people (including me) would point at the decent nucleophiles, not just every lone pair of electrons. Your instructor appears to want you to identify every site that could theoretically act as a Lewis base. It's an odd phrasing for that exercise, which is why you are getting conflicting answers.
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