Jacob
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Imine stability
Hi there!
How stable are imines after formation? There is a lot of literature saying that they are prone to hydrolysis and polymerization but not much on the
speed or effects of structure and conditions on these reactions.
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Dr.Bob
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Depends on both the carbonyl and the amine. Aldehyde imines are much less stable than ketones, and aromatic amines often give much more stable
imines than aliphatic. Most imine reactions make the imine in situ and then react it as it is made, such as reductive aminations. If you really
want to force the reaction, most people remove water by Dean Stark, sieves, harsh drying agents, or chemicals that react with the water and/or complex
the imine (eg, Ti(OiPr)4). Often adding an acid will speed up the formation.
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Jacob
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Thanks for the info! In the attached paper they make imines starting from acetaldehyde and methylamine. You'd think it should polymerize on the spot
but the yield after 2 days is 55%.
[Edited on 20-6-2019 by Jacob]
Attachment: BSCF1947_708.djvu (160kB)
This file has been downloaded 278 times
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