Pyrrolines, also known under the name dihydropyrroles, are three heterocyclic organic chemical compounds that differ in the position of the double bond. Pyrrolines are formally derived from the aromate pyrrole by hydrogenation. 1-Pyrroline is a cyclic imine, and 3-pyrroline is a symmetrical cyclic amine. 2-Pyrroline, an NH-containing enamine, labile with respect to trimerization.