Azanaphthalenes reactivity

Scheme V. Predicted Reactivity in Azanaphthalenes (Using the Activation-Numbering System)...

The reactivities of several azanaphthalene anion-radicals, alter polaro-graphic generation, are discussed by van der Meer.122,123 This includes the radicals of quinazoline and cinnoline whose ESR spectra do not appear to have been reported. The stability of carbon-halogen bonds in various azine anion-radicals, including quinoxaline and quinoline, has been discussed, as has the reactivity of quinoline anions toward alkyl halides.92,182 In the latter reaction alkylation occurs at the 1,2- and 2,4-positions. Heteroarylation of a range of electron-rich substrates by azine anion-radicals has been reported.183 No mechanism is implied in the available abstract, but the apparent electrophilicity on the part of the azine anions is surprising. 

The 2,i-orientation of an azine-nitrogen and a leaving group is characterized by activation which is exceptionally poor compared to other resonance activations. The poor activation, which is often grossly underrated, is still substantial relative to the substituted naphthalene 10 -10 -fold increase in the rates of alkoxylation and of alkylamination. The properties of 2,3,-orientation come into play in ail 3-substituted naphthalenes or azanaphthalenes which bear an azine-nitrogen or activating substituent in the 2-position (Section IV, A, 2). This orientation is subject to such a decrease in activation due to the relatively poor stabilization of charge in the ortho,ortho-quinoid structure (352) that 3-substituted isoquinolines and 2-nitro-naphthalenes are less reactive than 2-substitnted pyridines and nitrobenzenes (Section IV, A, 2). Insertion of a 3-aza moiety into a... 

---