UTILITY OF THE AZIDO-GROUP: ELECTRONIC STRUCTURE AND REACTIVITY OF o-OXOARYLNITRENIUM-BF3 IONS AND 2- (or 5-) AZIDOAZOLES DERIVATIVES

In the last decade, knowledge of the chemistry of N-arylnitrenium ions has advanced significantly and continue to attract attention arising from synthetic, theoretical and biological interest. Here we report the reactions of five 2-oxo arylnitrenium-BF3 ions generated from deactivated 2-oxoazidobenzenes, including 2-azidobenzenecarbaldehyde, 1-(2-azidophenyl)-1-ethanone, (2-azidophenyl) (phenyl)methanone , 2-azidobenzoic acid and 2-azidobenzenecarbonitrile, with Lewis acid BF3•OEt2 in the presence of benzene, as a possible source of 2-anilino-oxobenzenes and/or acridines. Synthesis of azido azoles: According to the proton-lithium (or halogen-lithium) exchange reaction via butyllithium, the metallation of the methylimidazole, the methylpyrazole and the thiazole rings occurs regioselectively at the C-2 (or at C-5 when the position-2 is unavailable) and the resulting 2-(or 5-) heteroaryllithium was employed for the azido transfer protocol with tosyl azide.