Correction to “Copper-Catalyzed Azide–Alkyne Cycloaddition of Hydrazoic Acid Formed In Situ from Sodium Azide Affords 4-Monosubstituted-1,2,3-triazoles”

Azide-free cyclization reaction access to 4-aryl-NH-1,2,3-triazoles: P-toluenesulfonyl hydrazide and sulfamic acid as nitrogen sources

“…Using DMF and DMA as solvents led to lower yields (entries 14 and 15). And the desired product 4a was not obtained in other solvents (CH 3 CN, THF, toluene, dioxane, and CH 3 NO 2 ) (entries [16][17][18][19][20]. Thus, the optimized conditions were established as follows: acetophenone 1a (0.1 mmol), p-toluenesulfonyl hydrazide 2 (0.2 mmol), and sulfamic acid 3 (0.6 mmol) in the presence of iodine (2.0 equiv.)…”

“…16 However, this process produces toxic azide acid, which poses a large health risk. 15,17 Accordingly, new azide-free routes to NH -1,2,3-triazoles without transition-metal catalysis must be developed.…”

How Dangerous Is Too Dangerous? A Perspective on Azide Chemistry

“…A recent article in this journal authored by Gazvoda et al describes a procedure for preparing triazoles from alkynes using stoichiometric sodium azide, stoichiometric acid, and catalytic copper, followed by a workup that may include dichloromethane. , As industrial chemists with decades of experience safely scaling up azide chemistry, we feel compelled to share with the research community our three major safety concerns with this procedure.…”