Synthesis of Diverse Benzotriazoles from Aryne Precursors Bearing an Azido Group via Inter- and Intramolecular Cycloadditions

A diverse range of benzotriazoles were synthesized from various 3-(azidoalkoxy)aryne precursors, which were easily prepared by Mitsunobu etherification. Various bis-1,2,3-triazoles containing a benzotriazole skeleton were obtained via sequential azide–alkyne and azide–aryne cycloadditions. Intramolecular azido–aryne cycloaddition, conducted using the same starting materials, afforded new types of ring-fused benzotriazoles. In the latter case, the reaction proceeded efficiently even though the regioorientation of the azido group was the reverse of that usually observed in intermolecular reactions between 3-alkoxyarynes and an azide. A diverse range of benzotriazoles were synthesized from various 3-(azidoalkoxy)aryne precursors, which were easily prepared by Mitsunobu etherification. Various bis-1,2,3-triazoles containing a benzotriazole skeleton were obtained via sequential azide–alkyne and azide–aryne cycloadditions. Intramolecular azido–aryne cycloaddition, conducted using the same starting materials, afforded new types of ring-fused benzotriazoles.