HFIP-Mediated Synthesis\nof 4‑Aryl-<i>NH</i>-1,2,3-Triazoles and 1,5-Disubstituted\n1,2,3-Triazolyl Glycoconjugates

We herein report a multicomponent reaction for the synthesis\nof <i>N</i>-unsubstituted-1,2,3-triazoles and <i>N</i>-substituted-1,2,3\ntriazoles from the reaction of aldehydes, nitroalkanes, and sodium\nazides/glycosyl azides in the presence of 1,1,1,3,3,3-hexafluoroisopropanol,\na hydrogen bond-donating reaction medium. This three-component reaction\nprovides a metal-free strategy for sequentially forming one C–C\nand two C–N bonds in a one-pot fashion. One-pot mild reaction\ncondition, operational simplicity, wide substrate scope, good functional\ngroup tolerance, easy purification, high reaction yields, and altogether\nexcellent regioselectivity are the notable advantages of this 1,2,3-triazole-forming\nprotocol. Moreover, this protocol provides practical access to the\ngram-scale synthesis of potent inhibitors of indoleamine 2,3-dioxygenase\n1.