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Chemistry Forums for Students => Organic Chemistry Forum => Organic Chemistry Forum for Graduate Students and Professionals => Topic started by: animanga008 on September 03, 2010, 08:53:29 PM

Title: Buchwald-Hartwig coupling question
Post by: animanga008 on September 03, 2010, 08:53:29 PM

I was wondering if anyone knowledgeable in palladium chemistry could explain why I was getting a clean, high yield reaction when I couple a secondary amine with 4-bromobenzaldehyde versus coupling the same amine with Methyl 4-bromobenzoate? What is it about the aldehyde that is preventing me from getting a decent reaction?

Thanks

Title: Re: Buchwald-Hartwig coupling question
Post by: MissPhosgene on September 12, 2010, 10:18:32 AM

Hi,

   If I were you I would look up the mechanism for that reaction in an organometallics book, for example. You may not find the exact one, but you should be able to piece things together. Then, I would look at the reactants and see how they can coordinate with the metal. You will find the answer there.

Best.

Title: Re: Buchwald-Hartwig coupling question
Post by: nox on January 09, 2011, 03:51:20 PM

Are you asking why your reaction ISN'T clean when you try to do the coupling with the aldehyde?

If so look at your reactants again. You have a secondary amine, and you're mixing that with an aldehyde (granted an aromatic aldehyde, but still an aldehyde nonetheless). That should set off some alarm bells.