Can hydrogen on platinum reduce carboxylic acids and esters?

Can $\ce{H2/Pt}$ reduce carboxylic acids and esters?


I am confused about the reducing nature of hydrogen in presence of platinum. In some books, it reduces carboxylic acid and ester while in others, not. I have checked Finar and Boyd books for it.




*This is based off my memory, as far as I can remember what my teacher taught me.*




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Note, instead of $\ce{Pt}$, you can go for $\ce{Ni}$ (or Raney Nickel) or even $\ce{Pd}$ as a catalyst.


Functional groups such as acid halide, cyanide, nitro, aldehyde, ketone, alkene, and alkyne are **easily reduced** by $\ce{H2/Ni}$. Some other groups can be reduced with $\ce{H2/Ni}$ as well, but if someone's asking you a question in an exam, they want you to refer to the list of groups which are *easily reduced* (more in the reactivity order below). So the answer in your case would be a *no*.


### Next, here's a reactivity order:


First, the groups which are easily reduced:


$$\begin{align} \text{acid halide} > \ce{R-C#C-R} > \ce{R-C=C-R} > \ce{R-CHO} > \\ &\text{ketone}> \ce{R-CN} > \ce{R-NO2} > \ldots \end{align}$$


Then the groups that are reduced only with difficulty:


$$ \ldots > \ce{R-X} > \text{benzene} > \ce{R-COOH} > \text{amide} > \text{ester} > \text{acid anhydride}$$


$\ce{R-X}$ would require temperatures around $\pu{50^\circ C}$, benzene would require a temperature of about $\pu{100^\circ C}$ and groups from carboxylic acid to acid anhydride would require temperatures around $200-\pu{250^\circ C}$.


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