Synthesis of New 1,3a,6,6a-Tetraazapentalene Derivatives under Cadogan Reaction Conditions

Abstract

A convenient synthetic approach has been developed for novel monobenzotriazoles incorporating a mesoionic 1,3a,6,6a-tetraazapentalene core. The method involves a Cu(I)-catalyzed (3+2) cycloaddition of ortho-nitrophenyl azide to terminal aryl(alkyl)acetylenes, followed by an intramolecular cyclization under Cadogan-type deoxygenation conditions. The process can be successfully performed in a one-pot fashion, affording the target benzo[d][1,2,3]triazolo[1,2-a]triazole derivatives in good yields.