In a reaction between an aliphatic primary amine and a ketone, I could expect a ketimine as a product or intermediate. My question regards tautomerization of this intermediate: has tautomerization between the two possible imine structures ever been observed, or is even possible? I tried to search imine tautomerism and transamination, but I can't find what I'm looking for. I imagine this would be a simple experiment to conduct, but I can't find anything in the literature on this.

Proposed ketimine tautomerism

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    $\begingroup$ Yes, this is common. One example is enzyme catalyzed transamination reactions that utilize pyridoxal phosphate as a cofactor. $\endgroup$
    – Andrew
    Feb 4, 2021 at 21:30

1 Answer 1


I found something very similar to what I sought in Dose, Nature 179, 734 (1957) though it involves aldimines and a decarboxylation step. The author gives a very well explained mechanism for the process and reports varying transamination ratios of valine based on the substitution of the aldehyde. An example:

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