Copper-catalyzed synthesis of aryl azides and 1-aryl-1,2,3-triazoles from boronic acids

Five‐Membered Heterocycles with Three Heteroatoms: Triazoles

“…Palladium-catalyzed synthesis of 1H-triazoles 75 from alkenyl bromides 74 and sodium azide in the presence of xantphos ligand has been reported (Scheme 12.33) [100]. A new one-pot procedure has been developed to synthesize 1-aryl-and 1-vinyl-1,2,3-triazoles directly from boronic acids and alkynes, which avoids the need to isolate unstable azide intermediates [101]. halogen, sulfur, silicon, tin, aldehyde, and ester products can be formed from these reactions.…”

Synthesis of heterocyclic N-(β-d-glucopyranosyl)carboxamides for inhibition of glycogen phosphorylase

“…The copper(I) catalyzed cycloaddition reaction (CuAAC) of 3 with aromatic azides was investigated first (Scheme 2). The noncommercial azides were prepared either in situ from the corre-80 sponding boronic acids following a recently published procedure 21 or from the related aniline derivatives via diazonium salts. 22 The widely used system CuSO 4 -L-ascorbic acid was applied to generate the catalyst, and the cycloadducts 4-8 were obtained in high yields.…”

Synthesis of variously coupled conjugates of d-glucose, 1,3,4-oxadiazole, and 1,2,3-triazole for inhibition of glycogen phosphorylase

“…Ethynyl-oxadiazoles 21-24 were cyclized with several azides under variants of the copper(I) catalysed azide-alkyne cycloaddition (CuAAC) conditions [27][28][29] (Scheme 2). The triazole ring formation from 21 was similarly efficient by using phenyl azide (conditions a) or by in situ generation of this reagent from the corresponding commercial boronic acid 30 (conditions b) to give 29. (a 74%) …”