Topic
Triazene
About: Triazene is a research topic. Over the lifetime, 759 publications have been published within this topic receiving 8714 citations. The topic is also known as: Triazene cleavage & 1-triazene.
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TL;DR: In this paper, the preparation of 2-azido-transfer reaction of 3-azide-selenophene 2 and 2-azaide-thiophenes using the appropriate heteroarylithium derivatives and tosyl azide, followed by fragmentation of intermediate triazene lithium salts is reported.
Abstract: The preparation, by azido-transfer reaction, of 2-azido-1 and 3-azido-selenophene 2 using the appropriate heteroarylithium derivatives and tosyl azide, followed by fragmentation of the intermediate triazene lithium salts is reported here. Different chemical reactivity and kinetic behaviour were observed for azides 1 and 2 in either 1,3-cycloaddition reactions, with (trimethylsilyl)acetylene and trimethyl(vinyl)silane, or thermal decomposition. Compound 1 gives cyclo-ANAE adducts (silylated triazole or triazoline)ca. three times faster than compound 2. Both the elusive triazoline adducts undergo rapid ring-contraction, with extrusion of nitrogen, to give rise to the corresponding 1-(selenophenyl)-2-(trimethylsilyl)aziridine (1b, 2b). Kinetic measurements of the unimolecular thermal decompositions afford distinct activation parameters: Ea= 21.5 and 30.4 kcal mol–1, ΔS‡=–10.7 and –0.9 cal mol–1 K–1 for 1 and 2. respectively. Experimental data, as a result of geometric and electronic disturbances exerted by the azido-group located at α- or β-positions of the selenophene ring, are qualitatively supported by measurement of 1H, 13C and 77Se NMR chemical shifts. The present experimental evidence and those previously obtained with related 2-azido- and 3-azido-thiophenes are corroborated with the determination of the structures and comparison between 13C substituent chemical shift (SCS) and charge distributions by using a semiempirical computational MNDO/PM3 method.
11 citations
TL;DR: In this article, it was shown that the extraordinary stability of triazenes formed by an azo coupling reaction of 5-nitrobenzo[c]-1,2-thiazole-3-diazonium with primary or secondary aromatic amines is caused by the fact that these substances are protonated at the heterocyclic nitrogen atom and not at the nitrogen atom of the triazene grouping.
11 citations
Journal Article•
TL;DR: The results can be interpreted by a mechanism in which the bistriazene behaves as an 'animal' (i.e. N-CH2-N) and undergoes anchimerically assisted fragmentation, via an iminium ion intermediate, to the monomethyltriazenes.
Abstract: N,N-Bis-[(1-aryl-3-methyltriazen-3-yl)-methyl]-methylamines, 'bistriazenes', have anti-tumour activity against the TLX5 and PC6 mouse tumours and inhibit the growth of tumour cells growing in culture, without metabolic activation. The biological activity of the bistriazene appears to derive from facile hydrolysis to the cytotoxic monomethyltriazene, Ar-N = N-NHMe, and it is suggested that the bistriazene may be a good prodrug from for the 'active' metabolite of the anti-tumour dimethyltriazene, Ar-N-N = N-NME2. A kinetic study of the bistriazene hydrolysis shows that the reaction is retarded by electron-withdrawing substituents in the aryl group. The results can be interpreted by a mechanism in which the bistriazene behaves as an 'animal' (i.e. N-CH2-N) and undergoes anchimerically assisted fragmentation, via an iminium ion intermediate, to the monomethyltriazene.
11 citations
TL;DR: A series of triazene derivatives 1-3, 1a-3a were synthesized by cou- pling of diazonium salts of amines with N-methylaniline / p-nitroaniline in acidic media.
Abstract: A series of novel triazene derivatives 1-3, 1a-3a were synthesized by the cou- pling of diazonium salts of amines (sulfaguanidine, sulfapyridine, sulfamethoxazole) with N-methylaniline / p-nitroaniline in acidic media. The structures of the synthesized com- pounds were confirmed by the spectral data (UV, IR, 1H-NMR, APCI-MS) and elemental anal- ysis. The effects of all the compounds on A 549 and L 929 cell lines growth were investigat- ed. The cytotoxic and antitumor activities of these compounds have not been in vitro aganist A 549 and L 929 cell lines.
11 citations
TL;DR: In this article, a new approach to benzylamines using triazene compounds has been developed that is facilitated by the lithiation of aryltriazenes followed by treatment with an electrophile.
11 citations