98154-50-8Relevant articles and documents
Cyclo-octacarbazole, a New Heterocyclic Paratropic Ring System
Mitchell, Glynn,Rees, Charles W.
, p. 403 - 412 (2007/10/02)
Photolysis of the 1-(1-naphthyl)benzotriazoles (5a,b,g,h) was found to give the deep red cyclooctacarbazoles (6a,b,g,h), a new heterocyclic ring system formed by an unusual cyclisation onto the naphthalene ring junction (Scheme 1).The 1H n.m.r. spectra and high chemical reactivity of these cyclo-octacarbazoles (6) are consistent with antiaromatic paratropic character, associated with the 16?-electron periphery (25), comparable with the isoelectronic fluorenyl anion (4).The strained butadiene portion of the cyclo-octacarbazoles (6) is reactive towards addition and cycloaddition reactions, forming a tricarbonyliron complex (27) and Diels-Alder adducts (28).Naphthylbenzotriazoles (5c,d,e) with lone pair bearing substituents (MeO, Cl, Br) adjacent to the triazole ring do not give cyclooctacarbazoles, but only products derived by cyclisation onto the naphthalene 2-position.On similar photolysis the quinolinyltriazoles (39) gives the stable ylides (40) and the acridinylbenzotriazole (45) gives the quinoacridine (46).Mechanisms are proposed for all of these reactions.
