Azides with aromatic rings

Sulfonylnitrenes are formed by thermal decomposition of sulfonyl azides. Insertion reactions occur with saturated hydrocarbons.168 169 With aromatic rings, the main products are formally insertion products, but they are believed to be formed through addition intermediates. 

Azepines. - Formation. The thermal and photolytic decomposition of aryl azides provides important routes to azepines via inter- and intra-molecular reactions of the derived nitrene with aromatic rings. New work has been reported on several aspects of this chemistry. 

Nitration of benzofuroxans (Section VII, A) and decomposition of polynitrophenyl azides, provide generally satisfactory routes to nitrobenzofuroxans. The nitro groups render the ring susceptible to nucleophilic attack (see Section VII,B). 4,6-Dinitrobenzofuroxan, 5,6-dinitrobenzofuroxan, and nitrobenzodifuroxan (34) act as acceptors in change-transfer complex formation with aromatic hydrocarbons. Nitrobenzofuroxans have not been reduced to the... 

As mentioned in Section VIII.F (Scheme 12), 1 reacts with aromatic azides to give [3 + 2] cycloadducts 47. Sulfonyl and phosphoryl azides, however, react with 1 in a different manner to afford five-membered ring compounds (Eqs. 23 and 24).79... 

Figure 2.2. The change with changing aromatic ring substituent X in the azide (az) ion selectivities (feaz/ s)obsd ( ) determined by analysis of the products of the reactions of ring-substituted 1-phenylethyl derivatives (X-l-Y) and ring-substituted cumyl derivatives (X-2-Y) in 50/50 (v/v) water/trifluoroethanol at 25 The selectivities are plotted...

Ring-Substituted Cumyi Derivatives. In contrast with the sharp change in the kinetic order for nucleophilic substitution of azide ion at 1-phenyl-ethyl derivatives with changing aromatic ring substituent X (Fig. 2.2), there is no corresponding change from SnI to Sn2 nucleophilic substitution of azide ion at... 

The transition states for the stepwise (fej, Fig. 2.3) and concerted (fecon) reactions of (4-MeO,X)-3-Y lie at distinct well-separated positions on the More O Ferrall diagram and show different sensitivities to changes in solvent polarity, meta substituents X at the aromatic ring, and the leaving group Y. For example, in 50 50 (v/v) water/trifluoroethanol (4-MeO,H)-3-Cl reacts with azide ion exclusively by a stepwise mechanism through the primary carbocation intermediate (4-MeO,H)-3" with a selectivity for reaction with azide ion and solvent of feaz/ s = 25 However, two-thirds of the azide ion substitution product obtained from the reaction of (4-MeO,H)-3-Cl in the less polar solvent 80 20 acetone/water forms by concerted bimolecular substitution and only one-third forms by trapping of the carbocation intermediate (4-MeO,H)-3 with a selectivity of k z/h = 8 The preferred... 

The organic derivatives of hydrazoic acid which contain an aromatic ring with nitro groups comprise an important group of initiators. Picryl azide (VII), m.p. 89-90°C is a typical example. It has been prepared both by the action of nitrous acid on trinitrophenylhydrazine (Purgotti [154], Schrader [155] and Korczynski [156]) and by the action of sodium azide on picryl chloride. Rathsburg [157] suggested... 

The reaction of 2-chloro-l,l-dialkyl-6-nitroacenaphthenes (8-10) with azide and p-toluenethiolate ions takes place by the S l mechanism74. This reaction gives the substitution products, despite the fact that the nitro group and the chlorine-bearing benzylic carbon are attached to different aromatic rings. 

---