Azides, Diazoalkanes, Diazirines, Azo-compounds, and Azines

MeOsC CH CHs CFs CFCl + EtsN-NHsOH.HCl - oxime - etc.] also yields 

2-Trifluorodiazoethane has featured in investigations of perfluorobicyclo-[2,2,0]hexa-2,5-diene (perfluoro- Dewar -benzene) as a dipolarophile [- the 7If-tautomer (71) (75%) at 0— 20 C during 4 weeks]. Bis(trifluoromethyl)diazo- 

Burger, W. Thenn, R. Rauh, and H. Schickaneder, Angew. Chem. Internat. Edn., 1974, 13, An. 

Phosphites and tris(dimethylamino)phosphine attack hexafluoroacetone azine in hexane at 0 C to yield [5,5,5-trifluoro-2,2,4-tris(trifluoromethyl)-l,3-diaza-3-pentenylidenejphosphoranes (82), not, as thought initially, l,2A -azaphos-phiridines. Bicyclic phosphoranes (83), formed via diaza-allyl anions (84), may be the 

Work on the thermal reaction between hexafluoroacetone azine and cyclohexane (see Vol. 2, p. 240) has been followed by an investigation of reactions involving 

---

Azides, Diazoalkanes, Diazirines, Azo-compounds, and Azines. Fluorinated alkanoyl azides have been dealt with already in other sections, mainly that concerned with isocyanates (see pp. 227,228, and 229). The azides CHFa Ns, (CFs)2C(N3) O SiMes, and (CF3)sC(Ns) O SOsO have been obtained from the reaction systems CHFsCl-NaNs-alkali-HsO-dioxan, (CF3)2CO-Me8Si N3,i and (CF3)2C(Ns) ONa-S2O5CIX (X = F or Cl), respectively. Eleven 2-azido-3,3>difluorocyclobutenes have been synthesized as indicated in Scheme 49 and converted thermally or photo-chemically into the corresponding 2,2-difluorocyclopropanes decomposition of the 1-cyano- and 1-methoxycarbonyl-cyclobutenes in the presence of electron ri( aromatics gave pyrrole derivatives. These results have been discussed in terms of the mechanistic pathways contained in Scheme SO Neber rearrangement with EtsN... 

---