Ethenamine

Ethenamine, also known as vinylamine, is an organic compound with the chemical formula C2H5N. It is an unsaturated amine, featuring a double bond between two carbon atoms, one of which is bonded to a nitrogen atom. Ethenamine is highly reactive and exists primarily in its tautomeric form, aminoacetaldehyde, which is an aldehyde with an amine group. This keto-enol tautomerism is characteristic of compounds with an alpha-hydrogen adjacent to a carbonyl group, though in this case, the "carbonyl" is effectively a masked imine.

Due to its instability, free ethenamine is rarely isolated. Instead, it is often generated in situ as a reactive intermediate in various chemical reactions. Its reactivity stems from the electron-rich double bond and the nucleophilic nitrogen atom. Ethenamine can undergo addition reactions across the double bond and reactions involving the amine group. It plays a role in certain organic syntheses, particularly in the formation of heterocyclic compounds. Its presence as a transient species is significant in understanding reaction mechanisms where its structure is inferred from the products formed. The study of ethenamine and its derivatives contributes to the broader understanding of amine chemistry and the behavior of unsaturated organic molecules.