The photochemical reactions of nitrogen-rich mesoionic 1,3-diphenyltetrazolium heterocycles and related compounds

Citation
S. Araki et al., The photochemical reactions of nitrogen-rich mesoionic 1,3-diphenyltetrazolium heterocycles and related compounds, J CHEM S P1, (19), 2001, pp. 2476-2482
Citations number
26
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1
ISSN journal
1472-7781 → ACNP
Issue
19
Year of publication
2001
Pages
2476 - 2482
Database
ISI
SICI code
1472-7781(20011007):19<2476:TPRONM>2.0.ZU;2-7
Abstract
Photochemical reactions of azo and triazo derivatives of mesoionic 1,3-diph enyltetrazolium heterocycles and related compounds were,studied. The reacti on paths were found to depend markedly on the types of substrate, substitue nt and reaction solvent giving diverse products. Upon irradiation of the 1, 1'3,3'-tetraphenylazoditetrazolium salt 1, the addition of hydrogen and ace tone to the N=N bond was observed in methanol and acetone, respectively, wh ereas the bond was cleaved in diethyl ketone to give the 5-aminotetrazolium salt 10. The corresponding radical cation 11 also gave the reduction produ ct in methanol. On the other hand, the 1,3-diphenyl-5-(phenylazo)tetrazoliu m salt 12 underwent nitrogen evolution giving the 1,3-diphenyltetrazolium s alt 13 via the, corresponding tetrazolium radical. Triazene derivatives 14 and 17 underwent an N-N bond cleavage to give tetrazolio-5-amide 4. The mes oionic triazene compounds bearing a tosyl 18 or cyano group 19 gave product s 20 and 23. Triphenylphosphinotriazene 24 liberated nitrogen to give phosp hinoimide 25 and its hydrolysis product 10. Tetrazolylamide 26 lost a pheny ldiazonium group from the 1,3-diphenylfetrazolium ring to give the guanidin e derivative 27.