Diverse Synthesis of Azoles: Construction of ortho‐Azidotetrazoles/Triazoletetrazoles through N‐N Cleavage of 2H‐Indazoles

Abstract

Herein, we report a conceptually new, general, and efficient approach for the synthesis of valuable ortho‐azido‐1,5‐disubstituted tetrazole and one‐pot synthesis of ortho‐triazoletetrazole derivatives mainly via PIDA mediated N‐N cleavage of the azole ring of 2H‐indazoles using TMSN3. This current methodology represents an array of unsymmetrical ortho‐azidotetrazole and ortho‐triazoletetrazole derivatives with wide functional group tolerance in good to excellent yields under mild reaction conditions. The practical utility of this reaction was showcased through successful scale‐up synthesis and a variety of subsequent derivatizations of ortho‐azidotetrazole products. Mechanistic investigations indicate that the reaction proceeds through a radical pathway.