760952-83-8Relevant academic research and scientific papers
A bile acid-based pyridino-triazole ligand for Cu(I)-stabilization and its application in Cu(I) catalyzed click reactions
Nayal, Aradhana,Pandey, Pramod S.
, (2020/10/23)
A bile acid based pyridino-triazole ligand to stabilize Cu(I) state has been developed. The ligand was found to catalyze click reactions of a number of alkynes and azides in presence of Cu(CH3CN)4.BF4 at very low catalyst
High-affinity multivalent wheat germ agglutinin ligands by one-pot click reaction
Beckmann, Henning S.G.,Moeller, Heiko M.,Wittmann, Valentin
scheme or table, p. 819 - 826 (2012/08/08)
A series of six mono-, di-, and trivalent N,N'-diacetylchitobiose derivatives was conveniently prepared by employing a one-pot procedure for Cu(II)-catalyzed diazo transfer and Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) starting from commercially available amines. These glycoclusters were probed for their binding potencies to the plant lectin wheat germ agglutinin (WGA) from Triticum vulgaris by an enzyme-linked lectin assay (ELLA) employing covalently immobilized N-acetylglucosamine (GlcNAc) as a reference ligand. IC50 values were in the low micromolar/high nanomolar range, depending on the linker between the two disaccharides. Binding enhancements β up to 1000 for the divalent ligands and 2800 for a trivalent WGA ligand, compared to N,N'-diacetylchitobiose as the corresponding monovalent ligand, were observed. Molecular modeling studies, in which the chitobiose moieties were fitted into crystallographically determined binding sites of WGA, correlate the binding enhancements of the multivalent ligands with their ability to bind to the protein in a chelating mode. The best WGA ligand is a trivalent cluster with an IC50 value of 220 nM. Calculated per mol of contained chitobiose, this is the best WGA ligand known so far.
Ligand-assisted, copper(II) acetate-accelerated azide-alkyne cycloaddition
Michaels, Heather A.,Zhu, Lei
supporting information; experimental part, p. 2825 - 2834 (2012/06/05)
Polytriazole ligands such as the widely used tris[(1-benzyl-1H-1,2,3- triazol-4-yl)methyl]amine (TBTA), are shown to assist copper(II) acetate-mediated azide-alkyne cycloaddition (AAC) reactions that involve nonchelating azides. Tris(2-{4-[(dimethylamino)
Chelation-assisted, copper(II)-acetate-accelerated azide-alkyne cycloaddition
Kuang, Gui-Chao,Michaels, Heather A.,Simmons, J. Tyler,Clark, Ronald J.,Zhu, Lei
experimental part, p. 6540 - 6548 (2010/12/19)
We described in a previous communication a variant of the popular Cu I-catalyzed azide-alkyne cycloaddition (AAC) process where 5 mol % of Cu(OAc)2 in the absence of any added reducing agent is sufficient to enable the reaction. 2-Picolylazide (1) and 2-azidomethylquinoline (2) were found to be by far the most reactive carbon azide substrates that convert to 1,2,3-triazoles in as short as a few minutes under the discovered conditions. We hypothesized that the abilities of 1 and 2 to chelate CuII contribute significantly to the observed high reaction rates. The current work examines the effect of auxiliary ligands near the azido group other than pyridyl for CuII on the efficiency of the Cu(OAc)2-accelerated AAC reaction. The carbon azides capable of binding to the catalytic copper center at the alkylated azido nitrogen in a chelatable fashion were indeed shown to be superior substrates under the reported conditions. The chelation between carbon azide 11 and CuII was demonstrated in an X-ray single-crystal structure. In a limited set of examples, the ligand tris(benzyltriazolylmethyl) amine (TBTA), developed by Fokin et al. for assisting the original Cu I-catalyzed AAC reactions, also dramatically enhances the Cu(OAc)2-accelerated AAC reactions involving nonchelating azides. This observation leads to the hypothesis of an additional effect of chelating azides on the efficiencies of Cu(OAc)2-accelerated AAC reactions, which is to facilitate the rapid reduction of CuII to highly catalytic CuI species. Mechanistic studies on the AAC reactions with particular emphasis on the role of carbon azide/copper interactions will be conducted based on the observations reported in this work. Finally, the immediate utility of the product 1,2,3-triazole molecules derived from chelating azides as multidentate metal coordination ligands is demonstrated. The resulting triazolyl-containing ligands are expected to bind with transition metal ions via the N(2) nitrogen of the 1,2,3-triazolyl group to form nonplanar coordination rings. The CuII complexes of bidentate T1 and tetradentate T6 and the ZnII complex of T6 were characterized by X-ray crystallography. The structure of [Cu(T1)2(H2O) 2](ClO4)2 reveals the interesting synergistic effect of hydrogen bonding, π-π stacking interactions, and metal coordination in forming a one-dimensional supramolecular construct in the solid state. The tetradentate coordination mode of T6 may be incorporated into designs of new molecule sensors and organometallic catalysts.
