IBX mediated oxidation to carboxylic acids

[Horza2002]

Hi all,

 

A few months ago, I posted about the use of IBX as an efficient oxidant to oxidise primary and seconday alcohols to aldehydes and ketones respectively. I've since found another use this, the efficient oxidation of primary alcohols to carboxylic acids without the need for transition metals.

 

http://pubs.acs.org/doi/abs/10.1021/ol050875o

 

In Situ Generation of o-Iodoxybenzoic Acid (IBX) and the Catalytic Use of It in Oxidation Reactions in the Presence of Oxone as a Co-oxidant

 

This method is as good as the method for aldehyde oxidation. Using acetonitrile:water as the solvent, heated to 70^oC, there is complete conversion to the corrosponding carboxylic acid. And, like before, simply cooling the reaction down to 0^oC to precipitate out the IBX is all that is required for a work up....when I have done it, I have often found that running the crude filtrate is passed through a short (about an inch) of silica gel gives 95% yield clean by NMR. Theres the added bonus, as decsribed in that paper, is that u only needed catalyitc IBX and use Oxone to get good yields.

 

I have used this method myself a lot recently, and it is very good. I know there are alot of methods to do this, but this is by far the easiest oen I have found so far. Just thought I'd share this with you all again as a follow up to the IBX aldehyde oxidation method.