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Author: Subject: Could Phenyl triflate undergo nucleophilic substitution?
NitreRat
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[*] posted on 3-6-2016 at 19:55
Could Phenyl triflate undergo nucleophilic substitution?


While most aliphatic alcohols can easily be converted to the corosponding alkyl halide with a the apropriate halogenating agent such as PBr3 then easily substituted with other nucleophiles, it seems phenol cannot. I'm not really sure why this is. I think it's because the stability of the phenoxide ion and the instability of a phenyl cation make phenol much more difficult to protonate compared to other alcohols and carboxylic acids. Can anyone confirm whether this is the case?

If phenol cannot be halogenated by conventional reagents, is the same true when more extreme leaving groups are attached such as a mesylate, tosylate or triflate group?
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DraconicAcid
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[*] posted on 3-6-2016 at 22:06


Phenyl halides simply don't undergo nucleophilic substitution unless they have strongly electron-withdrawing groups on them. Same with phenyl esters of halophosphonic acids (the expected intermediate in the reaction with phosphorus trihalides).



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