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Sodium borohydride on wet clay;

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solvent-free reductive amination of carbonyl compounds using microwaves.
Tetrahedron 54,23 pg.6293 (1998)

What's the Hive's consensus on this method, so far?
Post 108374 (dormouse: "Ketone -> Honey w/ NaBH4 + Microwaves! (Page 1) -ReFlux", Novel Discourse)
If it works with 25 ml it also works with 25 L.  Just a case of compartmented feedstock and a LT-thingy.
The funny thing is, it looks so much like Bariums wet method, but then with heat.

Post 534375 (Rhodium: "N-(?-Phenethyl)-Ketimines to 2° Amines", Methods Discourse)

In my opinion this is just a theroretically interesting method. In what way could it be more useful than any of the more established ones? Sure it might be useful when you have a really tricky substrate which refuses to behave like you want it to. But other than that... Naah!

A side note: Check the link in the first post. Our chief bee went under the title "Pimp Master". Tehee!  ;)

I'm just guessing here  ;) ; but it could well be that the clay/microwave combination enhances imine formation, and that this drives the reaction forward - and, further guessing, I would say that this method therefore is particularly useful when it comes to reducing some less easier formed imines.(?)

"The reactions of primary and secondary amines with aldehydes and ketones, respectively, are accelereated by microwaves under solvent-free conditions in the presence of montmorillonite K 10 clay to afford a high yield synthesis of imines and enamines."
Varma, Rajender S.; Dahiya, Rajender; Kumar, Sudhir; Tetrahedron Letters 38, 12 (1997) pp. 2039-2042

Also interesting: "A manipulatively simple and rapid method for the reduction of carbonyl compounds is described that is conducted under solventless "dry" conditions using NaBH4/alumina and microwave irradiation.", Tetrahedron Letters 38, 25 (1997) pp. 4337-4338. Doesn't this sound very familiar?  :)

Edit: all articles cited in this post can be found here: (Post 533836 (indole_amine: "Reactions promoted by Microwaves and Clays", Novel Discourse) (thx anyway, PK!)



EDIT:  I used the search engine and got zip for the two articles in question.

AND everytime I use the Hive spellchecker, it doesn't seem to work:

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, and inform them of the time the error occurred, and anything you might have done that may have caused the error.

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We have an unwanted bug in our bee hive.


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