88998-91-8Relevant academic research and scientific papers
Photoextrusion of Molecular Nitrogen from 5-Alkylidene-4,5-dihydro-1H-tetrazoles Substituted by Vinyl or Phenyl Groups. (E)-Aziridinimines and Novel Products
Quast, Helmut,Hergenroether, Thomas
, p. 2095 - 2102 (2007/10/02)
Direct irradiation of deuterated hydrocarbon solutions of the alkylidenehydrotetrazoles 11 affords quantitative yields of the aziridinimines (E)- and (Z)-12, besides molecular nitrogen, with (E)/(Z) ratios ranging from 95:5 (12e, -40 deg C) to >99: photocycloreversion into the corresponding isocyanides 16 and imines 17, which is induced by selective irradiations with light of shorter wavelengths.Photolysis of the alkenylidenedihydrotetrazole 18c at -40 deg C affords the 2-imino-3-vinylaziridine 20c which decomposes at higher temperatures.Irradiation of 18c at 20 deg C or partial photolysis at -40 deg C followed by warming to 20 deg C furnishes the spirocyclic product 19c.The analogous products 19a and b are obtained from 18a and b.The vinyl compound 19a very slowly isomerizes to the ethylidene compound 23 by a proton 1,3-shift.The spirocyclic structures 19 and 23 are based on mass and NMR spectra including (1)H,(1)H and (13)C,(1)H COSY and extensive (1)H,(1)H decoupling experiments.The formation of the spirocycles 19 is interpreted in terms of a photoextrusion of molecular nitrogen from 18 to afford 3-vinylaziridinimines 20 which, at higher temperatures, rearrange to the 1,3-diazabutadienes 24 by a hydrogen homo- or -shift. Cycloaddition of 24 to unchanged 18 eventually yields the spirocycles 19. Key Words: 1H-Tetrazoles, 5-alkylidene-4,5-dihydro- / Aziridines, 2-imino- / 1,3-Diazabutadienes / Spirodeca-2,7-dienes, 1,2,3,4,6,8-hexaaza- / Photoextrusion of molecular nitrogen / Photocycloreversion / Hydrogen shift, homo- and homo- / Cycloaddition
