Triazenes
Triazenes are organic compounds that contain the functional group R1−N=N−NR2R3, where the R are each any of various types of substituent groups.[2] Some medications and dyes are triazenes.[3] Formally, the triazenes are related to the unstable chemical triazene, H2N−N=NH.
Production
[edit]Triazenes are prepared from the N-coupling reaction between diazonium salts and primary or secondary amines.[4] The coupling reactions are typically mild, using a base such as sodium acetate,[5] sodium carbonate,[5] or sodium bicarbonate.[4]
The diazonium reagents are themselves available starting from amines. For symmetrical triazenes derived from primary amines, partial diazotization gives a mixture of the original amine and its diazo derivative that then couple with each other. For example, 1,3-diphenyltriazene (PhN=N−NHPh) can be made from aniline in a one-pot reaction.[5][6] For asymmetrical triazenes, for example (phenyldiazenyl)pyrrolidine (PhN=N−NC4H8), the phenyldiazonium salt must be pre-made.
Analogues of Tröger's base containing a symmetric pair of asymmetric triazene side-chains have been obtained similarly.[7]
Reactions and applications
[edit]Polymeric triazenes are applied as conductive and absorbent materials.[8]
Triazenes are bidentate ligands, reacting to form either a four-membered ring or a dinuclear 8-membered ring.[9] They have been used in the synthesis of cinnoline, functionalized lactams, and coumarins.[10][11]
In the presence of protonating or alkylating agents, triazenes decompose into ammonium and diazonium salts.[11] For example, triazenes have been used as in situ diazonium in thiophenol synthesis:[5]
A strategy for the protection and deprotection of sensitive secondary amines is also based on this principle.[10]
Triazenes derived from primary amines engage in tautomerism:
(The tautomers are identical for symmetric triazenes.)
Oxidation generates the highly electrophilic azidium intermediate cation:[12]
References
[edit]- ↑ "Dacarbazine". The American Society of Health-System Pharmacists. Archived from the original on 11 September 2017. Retrieved 8 December 2016.
- ↑ Suleymanov, Abdusalom A.; Severin, Kay (2021-03-22). "Vinyl and Alkynyl Triazenes: Synthesis, Reactivity, and Applications". Angewandte Chemie International Edition. 60 (13): 6879–6889. doi:10.1002/anie.202011031. ISSN 1433-7851.
- ↑ Berneth, Horst (2008). "Methine Dyes and Pigments". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a16_487.pub2. ISBN 978-3-527-30673-2.
- 1 2 Sengupta, Saumitra; Sadhukhan, Subir K. (2002). "Synthesis of Symmetrical trans-Stilbenes by a Double Heck Reaction of (Arylazo)amines with Vinyltriethoxysilane: trans-4,4′-Dibromostilbene". Organic Syntheses. 79: 52. doi:10.15227/orgsyn.079.0052.
- 1 2 3 4 Kazem-Rostami, M.; Khazaei, A.; Moosavi-Zare, A. R.; Bayat, M.; Saednia, S. (2012). "Novel One-Pot Synthesis of Thiophenols from Related Triazenes under Mild Conditions". Synlett. 23 (13): 1893–1896. doi:10.1055/s-0032-1316557. S2CID 196805424.
- ↑ Hartman, W. W.; Dickey, J. B. (1934). "Diazoaminobenzene". Organic Syntheses. 14: 24. doi:10.15227/orgsyn.014.0024.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ↑ Kazemostami, Masoud (2017). "Facile preparation of Ʌ-shaped building blocks: Hünlich-base derivatization". Synlett. 28: 1641–1645. doi:10.1055/s-0036-1588180. S2CID 99294625.
- ↑ Khazaei, A.; Zare, A.; Moosavi-Zare, A. R.; Sadeghpour, M.; Afkhami, A. (2013). "Synthesis, characterization, and application of a triazene-based polysulfone as a dye adsorbent". Journal of Applied Polymer Science. 129 (6): 3439–3446. doi:10.1002/app.39069.
- ↑ Haiduc, Ionel; Silaghi-Dumitrescu, Ioan (1986) [28 February 1986]. "Inorganic (carbon-free) chelate rings". Coordination Chemistry Reviews. 74. Amsterdam: Elsevier: 144–147. doi:10.1016/0010-8545(86)85004-4.
- 1 2 Lazny, R.; Poplawski, J.; Köbberling, J.; Enders, D.; Bräse, S. (1999). "Triazenes: A Useful Protecting Strategy for Sensitive Secondary Amines". Synlett. 1999 (8): 1304–1306. doi:10.1055/s-1999-2803.
- 1 2 Kimball, D. B.; Haley, M. M. (2002). "Triazenes: A Versatile Tool in Organic Synthesis". Angewandte Chemie International Edition. 41 (18): 3338–51. doi:10.1002/1521-3773(20020916)41:18<3338::AID-ANIE3338>3.0.CO;2-7. PMID 12298030.
- ↑ Wirschun, Wolfgang; Maier, Gerd-Michael; Jochims, Johannes C. (1997). "On the reaction of 1,3-diaza-2-azoniaallene salts with 1,3-butadienes and cumulenes". Tetrahedron. 53 (16). doi:10.1016/S0040-4020(97)00283-4.
