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,[1] and 3-pyrroline is a symmetrical cyclic amine. 2-Pyrroline, an NH-containing enamine, labile with respect to trimerization.
The three parent pyrrolines are colorless, volatile liquids.
| Property | 1-Pyrroline | 2-Pyrroline | 3-Pyrroline |
|---|---|---|---|
| Structure | |||
| CAS Registry Number | 5724-81-2 | 638-31-3 | 109-96-6 |
| PubChem CID | 79803 | 94395 | 66059 |
| Melting Point (°C) | — | — | −57 |
| Boiling Point (°C) | 87 | 90–91 | |
| Notable examples | 1-pyrroline (parent)[1] 1-pyrroline-5-carboxylic acid myosmine pyrrolysine 2-acetyl-1-pyrroline | 2-acetyl-2-pyrroline | 3-pyrroline (parent)[2] |
N-substituted pyrrolines can be generated by ring-closing metathesis.[3]
See also
- Pyrrole, the aromatic analog with two double bonds
- Pyrrolidine, the fully saturated analog without double bonds
- Indoles and isoindoles, pyrrolines fused to a benzene ring
References
- ^ Baxter, George; Melville, Jill C.; Robins, David J. (1991). "Stabilisation of 3,4-Dihydro-2H-pyrrole (1-Pyrroline) by Complexation with Zinc Iodide". Synlett. ' (5): 359–360. doi:10.1055/s-1991-34733
- ^ Meyers, Albert I.; Warmus, Joseph S.; Dilley., Garrett J. (1996). "3-Pyrroline". Organic Syntheses. 73: 246. doi:10.15227/orgsyn.073.0246
- ^ Ferguson, Marcelle L.; O'leary, Daniel J.; Grubbs, Robert H. (2003). "Ring-closing Metathesis Synthesis of N-Boc-3-pyrroline". Org. Synth.. 80: 85. doi:10.15227/orgsyn.080.0085
External links
- Pyrroline, 1-pyrroline, 2-pyrroline, and 3-pyrroline at EMBL-EBI