Triazole: the Keystone in Glycosylated Molecular Architectures Constructed by a Click Reaction

Abstract

The copper(I)-catalyzed modern version of the Huisgen-type azide-alkyne cycloaddition to give a 1,4-disubstituted 1,2,3-triazole unit is introduced as a powerful ligation method for glycoconjugation. Owing to its high chemoselectivity and tolerance of a variety of reaction conditions, this highly atom-economic and efficient coupling reaction is especially useful for the effective construction of complex glycosylated structures such as clusters, dendrimers, polymers, peptides, and macrocycles. In all cases the triazole ring plays a key role by locking into position the various parts of these molecular architectures. The examples reported and briefly discussed in this short review highlight the use of this reaction in carbohydrate chemistry and pave the way to further developments and applications.

Lube Oil Wear Reduction via Organic Tribofilms

“…Reduction in the d-spacing after functionalization, indicated that upon functionalization, the structure of the samples was changed due to the amorphization of the material by introducing the organic moiety into the interlayer spacing of GO. For all four different rGOf, one crucial peak can be seen at 2358 cm −1 indicating the stretching of C-N, proving the success of azide-alkyne coupling reaction on the GO sheets [27,31]. The intensities of the peaks indicating the presence of oxygen-containing functionalities showed a dramatic reduction from GO to rGOf.…”

Synthesis of Sugar‐Based Silica Gels by Copper‐Catalysed Azide–Alkyne Cycloaddition via a Single‐Step Azido‐Activated Silica Intermediate and the Use of the Gels in Hydrophilic Interaction Chromatography

“…In both cases, multiple azide-alkyne coupling allowed the sugar fragments to be linked to the calix [4]arene scaffold through 1,4-disubstituted 1,2,3-triazole tethers, thus leading to the metaphoric view of the triazole as a formidable keystone in glycosylated molecular architectures. [23] With the above azido-activated silica supports in hand, ethynyl C-galactoside 1 and propargyl O- Table 1. Surface coverage data of the azido-activated silica gels obtained in a single step and the prepared sugar-silica gels.…”

Evaluation of bis-triphenylphosphano-copper(I)-butyrate (C3H7COOCu(PPh3)2) as catalyst for the synthesis of 1-glycopyranosyl-4-substituted-1,2,3-triazoles

“…Synthesis as well as application of 1,2,3-triazole containing simple glycosides, oligosaccharides, glycomacrocycles, glycoclusters, glycodendrimers, glycopeptides, glycoarrays, glycopolimers and glycosylated biomolecules were surveyed in several reviews. [3][4][5][6] 1-Glycosyl-1,2,3-triazole derivatives were obtained from relatively easily available glycosyl azides by using diverse Cu(I) sources.…”

“…In situ reduction of Cu(II) salts, usually CuSO 4 or Cu(OAc) 2 by Naascorbate or L-ascorbic acid [7][8][9][10][11][12][13][14][15][16] as well as by Cu turnings 11,17 is one of the most commonly used possibilities for the catalysis, whereby, with unprotected glycosyl azides, addition of o-phenylenediamine 18 proved advantageous. CuI is another often applied catalyst in the presence of either DIPEA or Et 3 N with TBTA (N,N,Ntris-[(1-benzyl-1H-1,2,3-triazole-4-yl)methy]amine).…”