Can Carboxylic Acids convert to Amides?

[ipodtouch]

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I'm going through the BR, and it emphasizes over and over again that Carboxylic acids can be converted to esters, anhydrides, and acid halides.
But it never mentions Amides.


I'm wondering why carboxylic acids cannot become amides.
NR2- is a much stronger base than OH-, hence I would think that regular attack on the carbonyl carbon should kick off the OH.

Unless there is something about OH that I am missing?

 

[SaCkO]

Yes Very True, and an example is protein synthesis(peptide bond formation) where one amino group of an amino-acid attacks the carbonyll carbon on another amino acid forming an amide group and releasing water

 

[pfaction]

TPR says similar; that COOH and NH+ would react in acid-base or whatever, it takes enzymatic catalysis to form an amide bond via condensation.

 

[BerkReviewTeach]

I'm going through the BR, and it emphasizes over and over again that Carboxylic acids can be converted to esters, anhydrides, and acid halides.
But it never mentions Amides.


I'm wondering why carboxylic acids cannot become amides.
NR2- is a much stronger base than OH-, hence I would think that regular attack on the carbonyl carbon should kick off the OH.

Unless there is something about OH that I am missing?

Think about what would happen with a bunch of uncharged amino acids. Do they spontaneously form linkages from the amine group attacking the carbonyl carbon and displacing the OH group? They don't. Instead, the amine group deprotonates the carboxyl proton. So if a neutral amine is a strong enough base to deprotonate a carboxylic acid proton, then an amide (R2N-) will definitely deprotonate the carboxylic acid.

To convert an acid into an amide, you must treat the acid with a catalyst or convert the OH group to something more reactive. You can't do it with straight addition of an amine (or R2N-) to a carboxylic acid.

 

[hellocubed]

They don't. Instead, the amine group deprotonates the carboxyl proton. So if a neutral amine is a strong enough base to deprotonate a carboxylic acid proton, then an amide (R2N-) will definitely deprotonate the carboxylic acid.

Oh shiz

Boss explanation there.