Remember that I congratulated Matthias Beller and co-workers for selectively reducing amides in the presence of anything else? Only caveat: The amides absolutely needed to be tertiary.

Only a week or so after posting (I swear to all holy things I had no idea know Beller was incoming), I attended his lecture, and several people in the audience asked Beller if they were working to address this little detail, i.e. whether there will be a recipe for primary and secondary amides too. He assured us it would soon be fixed, and then actually pulled out a couple of back-up slides demonstrating on-going action in the specific area.

I have since had Beller on my radar, because if one can selectively reduce any amide in the presence of anything else, it changes everything.

Today I noticed this publication:

Reduction of primary amides

Tetrahedron Lett. 2011, 52, 4072-4075. (DOI: 10.1016/j.tetlet.2011.05.109)

This one is awesome in many ways. Firstly, they use my pet Lewis acid titanium isopropoxide, which has come to the rescue in so many different projects for me before, and secondly they show how primary amides can now be reduced by employing a variation of Beller’s strategy.

However, this is a preliminary report, and the functional group tolerance can be questioned (the table is not that exhaustive) – but still… whoa!

Now, we are all anxiously waiting for the end game: Beller’s full paper showing the world the ultimate recipe for taking down any amide without harming ketones, esters, nitro groups, esters and other fragilities.

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4 Responses to Amide reductions: The saga continues

  1. For a catalytic reduction of amides with H2, have a look at Cole-Hamilton’s paper: Chem. Commun. 2007, 3154. Might be interesting to compare/contrast.

  2. drfreddy says:

    Will look into it! Thanks. The direct link is DOI: 10.1039/B706635J
    Does it address the selectivity issues associated with amide reductions in general, amides often being the most stubborn functional group of them all in accepting a new set of hydrogens?

  3. Don’t recall much on selectivity in Cole-Hamilton. You can also have a look at Milstein’s JACS in 2010. In true Milstein style, it’s catalyzed by a Ru-pincer complex. Here’s the DOI:
    10.1021/ja1080019

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