JefferyH - 2-7-2014 at 22:21
I found it very strange that I can't find much information on this topic. Like, any, at all.
From my research I have found that when Imines are formed on Aromatics, they tend to be much more resistant against hydrolysis by water, probably due
to resonance and due to the electron donating capacity of the aromatic ring to stabilize the electrophilic nature of the imine. I also haven't been
able to find any information on that, that imines are stabilized by electron rich groups on molecules... which should be relatively common sense.
I've particularly found this interesting idea when noticing that aromatic imines once allowed to form can be hydrogenated in aqueous solutions without
any formed alcohol. In contrary, the only information on imine stability I can find is that they are very unstable and hard to form in water and
require very specific PH.
Are their any other stabilizing factors I should be aware of?
zed - 3-7-2014 at 11:34
Be more specific. What actual reaction are you contemplating?
JefferyH - 3-7-2014 at 12:56
Be more specific? What are you talking about? I am asking about general theory here.
It is generally regarded that imines are difficult to form completely in the presence of water, but there is obviously some reason for this, and I
want to understand why. Yes I know it varies depending on the molecular structure, but there should be general features that induce certain effects.
Imines like any other functional group have their properties - imines being electrophilic. As well, like any other group, electrons tend to be
delocalized and thus stabilized on aromatic molecules. Rather, the more substituted form is the one that is stabilized. Electron donating groups seem
to assist this stabilization of unstable electrophilic functional groups.
My reason for posting is I am wondering why I was never able to find information on this, but instead had to pick it up naturally from reading various
papers? Is there no specific books(or papers) that would cover this particular topic? The idea of resonance stabilization is touched on briefly in
some text books, but no book that I have ever seen goes into depth about how the reactivity of certain function groups are affected by molecular
resonance or other surrounding groups that can shift the polarity.
This seems to me to be a very basic topic, resonance, alternating bonds, delocalization of electrons, electron rich groups, electron deficient groups,
and so on, so where can I find detailed information on this? Or has the topic never been fully analyzed and written about?
[Edited on 3-7-2014 by JefferyH]
forgottenpassword - 3-7-2014 at 13:32
http://www.sciencedirect.com/science/article/pii/S0040403909...
[Edited on 3-7-2014 by forgottenpassword]
Attachment: 79e4150169b80796bc.pdf (187kB)
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aga - 3-7-2014 at 14:14
Knowing next to chem nothing, i certainly cannot help you, other than to say that if you cannot find material on the topic,then maybe it's New
(unresearched) or Valuable (researched and unavailable publicly)
I would appreciate any starting point relating to the Resonance that you mentioned.
AvBaeyer - 3-7-2014 at 21:01
JefferyH:
I strongly suggest you find a copy of Bruice and Benkovic "Bioorganic Mechanisms" Volume 2, and study Chapter 8. Most of what you want to know about
imine chemistry should be addressed there. This is an older book (1966) and should be in a good library.
Another good tome along the lines you ask about is L.N. Ferguson "The Modern Structural Theory of Organic Chemistry." This book is not so modern
(1963) but the information is still most relevant. Lots of basic stuff you won't be taught in school anymore.
AvB