A series of carbohydrate-linked 1,2,3-triazole derivatives were synthesized in good yields from glucofuranose and allofuranose diacetonides using as key step a three-component 1,3-dipolar azide–alkyne cycloaddition catalysed by a Cu–Al mixed oxide. In this multi-component reaction, Cu–Al mixed oxide/sodium ascorbate system serves as a highly reactive, recyclable and efficient heterogeneous catalyst for the regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles. The reported protocol has significant advantages over classical CuI/
N
,
N
-diisopropylethylamine (DIPEA) or CuSO
4
/sodium ascorbate conditions in terms of efficiency and reduced synthetic complexity. In addition, the selective deprotection of synthesized di-
O
-isopropylidene derivatives was also carried out leading to the corresponding mono-
O
-isopropylidene products in moderate yields. Some of the synthesized triazole glycoconjugates were tested for their
in vitro
antimicrobial activity using the disc diffusion method against Gram-positive bacteria (
Staphylococcus aureus
and
Bacillus subtilis
), Gram-negative bacteria (
Escherichia coli
and
Pseudomonas aeruginosa
), as well as fungus (
Aspergillus niger
) and yeast (
Candida utilis
). The results revealed that these compounds exhibit moderate to good antimicrobial activity mainly against Gram-negative bacteria.
Cu–Al mixed oxide-catalysed multi-component synthesis of gluco- and allofuranose-linked 1,2,3-triazole derivatives
