A series of carbohydrate linked-1,2,3-triazole derivatives were synthetized in good yields from glucofuranose and allofuranose diacetonides using as key step a three-component 1,3-dipolar azide-alkyne cycloaddition catalyzed by a Cu-Al mixed oxide. In this multicomponent reaction, Cu-Al mixed oxide/sodium ascorbate system serves as highly reactive, recyclable and efficient heterogeneous catalyst for regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles. The reported protocol has significant advantages over classical CuI/DIPEA or CuSO₄/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 disk 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.

NMR spectra were recorded on a Bruker Ascend-400 (400 MHz) and Bruker Avance DMX-500 (500 MHz) spectrometers in CDCl₃ or acetone-d₆ and chemical shifts are given in ppm with TMS as the reference.

Raw NMR data (including ¹H, ¹³C, COSY, HSQC and HMBC experiments) for new synthetized compounds.