What is the mechanism for demercuration of organomercurial alcohol?

[amb123]

Can someone point me in the right direction to find a page that gives the actual mechanism for this reaction? My book just says "... demercuration, to remove the mercury. Sodium borohydride replaces the mercuric acetate fragment with hydrogen. Then it gives the reaction

4 organomercurial alcohol + NaBH4 + 4 -OH --> 4 Alcohol + NaB(OH)4 + 4Hg + 4 -OAc.

I don't know how this actually takes place, and my organic book doesn't explain it:( Any references or links would be helpful. The searches I got just mentioned it, didn't give the mechanism.

Thanks!
-A

 

[Evalesco]

Confused Student

Hi A Confused Student - it sounds like you're looking for a more in depth explanation of the mechanism behind this reaction. I recommend checking out the Organic Chemistry Portal website. They have an extensive library of reaction mechanisms, and you should be able to find what you need there. Good luck!

 

[ravenprp]

The mechanism for demercuration of organomercurial alcohol involves the use of sodium borohydride (NaBH4) as a reducing agent. This reaction is typically carried out in the presence of a base, such as sodium hydroxide (NaOH), to facilitate the elimination of the mercury atom.

The first step in the mechanism is the addition of NaBH4 to the organomercurial alcohol, forming an intermediate species with a boron-hydrogen bond. This intermediate then undergoes a nucleophilic attack by the hydroxide ion, resulting in the displacement of the mercury atom and formation of a borate ester.

The final step in the mechanism is the hydrolysis of the borate ester to yield the desired alcohol product and regeneration of NaBH4. The overall reaction can be represented as follows:

R-Hg-OH + NaBH4 + OH- → R-OH + NaB(OH)4 + Hg

For a more detailed explanation and illustration of the mechanism, you can refer to organic chemistry textbooks or online resources such as ChemLibreTexts (https://chem.libretexts.org/Bookshe...ons/Demercuration_of_Organomercurial_Alcohols) or Master Organic Chemistry (https://www.masterorganicchemistry....omercurial-compounds-with-sodium-borohydride/).