The first study of a copper(I)-catalyzed azide-alkyne click reaction in ionic liquids (ILs) is reported. The cycloaddition of a sugar azide with a sugar acetylene (CuI, i-Pr(2)EtN, 80 degrees C) was carried out in 10 ILs as well as in standard molecular solvents (toluene and DMF) to give the 1,4-disubstituted triazole-linked C-disaccharide. The highest yields (84 and 95%) were registered in Ammoeng 110 and [C(8)dabco][N(CN)(2)]. The latter solvent was recycled in four subsequent reactions without loss of the reaction efficiency. Reactions carried out in the absence of the Hunig's base afforded mixtures of 1,4- and 1,5-disubstituted triazole regioisomers.
|Autori:||Marra A; Vecchi A; Chiappe C; Melai B; Dondoni A|
|Titolo:||Validation of the copper(I)-catalyzed azide-alkyne coupling in ionic liquids. Synthesis of a triazole-linked C-disaccharide as a case study|
|Anno del prodotto:||2008|
|Digital Object Identifier (DOI):||10.1021/jo7026454|
|Appare nelle tipologie:||1.1 Articolo in rivista|