Acid catalysts used for turning acid halides and acid anhydrides into Carboxylic acids?

[510586]

Hi everyone. On Chad's videos, he says that you use H2O then H+ or H3O+ to turn acid halides and acid anhydrides into carboxylic acids. My former teacher said that H2O works alone since the acid halides and acid anhydrides are already acidic, so they do not need an acid catalyst. Of course I will listen to Chad since he knows more about the DAT, but does anyone know the reasoning behind it?

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[FeralisExtremum]

From my notes on Chad's stuff, I think he specifically says that H2O alone will work for turning acid halides and acid anyhydrides because the leaving group is good enough. It's everything else in his heirarchy (esters, amides, etc) that need H3O+ to become carboxylic acids.

 

[510586]

Oh ok cool thanks. Gotta be more careful on my note taking.

 

[DAT Destroyer]

Hi everyone. On Chad's videos, he says that you use H2O then H+ or H3O+ to turn acid halides and acid anhydrides into carboxylic acids. My former teacher said that H2O works alone since the acid halides and acid anhydrides are already acidic, so they do not need an acid catalyst. Of course I will listen to Chad since he knows more about the DAT, but does anyone know the reasoning behind it?

Your teacher is indeed correct, an acyl halide and even an anhydride both easily react with water. Water functions as the nucleophile and can attack the carbonyl group. The carbonyl group is reformed by expelling the leaving group.

I have personally done this reaction many times with just water while at NYU.

Hope this helps.

Dr. Romano

 

[510586]

Yea I think I forgot to write it down. Thanks!