Iminium ion

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Iminium ions , also iminium cations, are mesomeric stabilized organic cations with a bond between a nitrogen atom and a carbon atom.

Mesomeric boundary structure of an iminium ion, R stands for a hydrogen atom , an organic radical or another radical (e.g. alkoxy group ), it being possible for the radicals to be identical or different.

Reactions in which iminium ions are formed as intermediates (selection)

Production and occurrence

Iminium ions arise as an intermediate z. B. in the dehydration of hemi-aminals . One often speaks of a “protonated imine” when talking about an iminium ion. This name comes from the fact that imines become iminium ions through protonation. The iminium ion is subject to a mesomerism, which affects its reactivity. A mesomeric limit form is then a carbenium ion. Chloride salts of N- acylated iminium ions are formed when imines are reacted with carboxylic acid chlorides .

Mesomerism-stabilized boundary structures: iminium ion (left) and carbenium ion. R stands for a hydrogen atom, an organic radical or another radical (e.g. alkoxy group ), it being possible for the radicals to be identical or different.

Examples

Since the iminium ion can have very different forms, some examples will now be given here to illustrate the variety of possibilities.

See also

Individual evidence

  1. Joachim Buddrus: Fundamentals of Organic Chemistry , 4th Edition, de Gruyter Verlag, Berlin, 2011, pp. 40–41, ISBN 978-3-11-024894-4 .
  2. a b c K. PC Vollhardt , NE Schore: Organische Chemie , 4th edition, Wiley-VCH, Weinheim 2005 , ISBN 978-3-527-31380-8 , p. 879.
  3. W. Schwarze, K. Drauz, J. Martens: Reaction of 3-thiazolines with carboxylic acid chlorides , Chem.-Ztg. 1987, 111, pp. 149-153.