Iridium(III)-Catalyzed Direct C-H Sulfonamidation of 2-Aryl-1,2,3-triazole N-Oxides with Sulfonyl Azides

We have developed a method for the direct sulfonamidation of 2-aryl-1,2,3-triazole N-oxides using sulfonyl azides as the amino source to release molecular nitrogen as the sole by-product. This protocol exhibits excellent functional group tolerance and proceeds efficiently under external oxidant-free conditions. Various 2-(2-sulfonamidoaryl)-1,2,3-triazoles were prepared in up to 97% yields for 25 examples with excellent regioselectivity.