Multivalent Neoglycoconjugates by Regiospecific Cycloaddition of Alkynes and Azides Using Organic-Soluble Copper Catalysts

Abstract

[reaction: see text] The construction of multivalent neoglycoconjugates is efficiently achieved by the regiospecific catalytic cycloaddition of alkynes and azides using the organic-soluble copper complexes (Ph(3)P)(3).CuBr and (EtO)(3)P.CuI. The simultaneous use of microwave irradiation shortened notably the reaction times.

[(NHC)2Cu]X Complexes as Efficient Catalysts for Azide–Alkyne Click Chemistry at Low Catalyst Loadings

“…Thanks to its mild conditions and high efficiency, this reaction has found a myriad of applications in biology and material science. [4] Less attention has been focused on the development of novel copper(I)-based well-defined systems [5,6,7] and to the amount of copper used. [8] This last point is extremely important for future industrial applications and it might be one of the last challenges to overcome for this transformation.…”

“…[12] On the other hand, we have also studied a family of cationic NHC-containing complexes of general formulae [(NHC) 2 Cu]X (X = PF 6 , BF 4 ). [13] Interestingly, during the examination of their activity in the hydrosilylation of ketones we observed an enhanced reactivity of these complexes when compared to their neutral analogues [(NHC)CuCl].…”

“…We attribute this result to the extreme instability of C in the absence of a protic source. On the contrary, when a mixture of A and B was reacted with the azide, a clean formation of triazole 8a was obtained, along with the regeneration of [(ICy) 2 Cu]PF 6 .…”

Dendrimers Clicked Together Divergently

“…46 The Huisgen 1,3-dipolar cycloaddition between azides and alkynes 47 to yield triazoles meets the requirements for definition as a Click reaction 48 and has recently been utilized to functionalize surfaces, [49][50][51][52] polymers, 53,54 and sugars, [55][56][57] probe biological systems, [58][59][60][61][62] participate in multicomponent cascade reactions, 63,64 build libraries, 65,66 and synthesize analogues of vitamin D. 67 Because of toleration of a wide range of functionalities and high yielding reactions, the Huisgen 1,3-dipolar cycloaddition Click reaction between azides and alkynes is an obvious tool for building macromolecules, [68][69][70][71] and dendritic macromolecules, as demonstrated by the recent employment of this Click reaction to construct dendrimers convergently. 72 Both the convergent and divergent synthetic methodologies provide routes for the production of dendritic macromolecules; however, each has specific advantages.…”

Synthesis and characterization of biotin derivatives as multifunctional oligosaccharide tags

“…It has become a mild, efficient, and widely-used method to synthesize five-membered ring 1,2,3-triazoles and has high compatibility with functional groups (alcohols, carboxylic acids, amines) in different solvent systems, including water. In the field of carbohydrate chemistry, click chemistry has been used for the synthesis of glycoconjugates 26,27 and carbohydrate macrocycles 28,29 in which a sugar possessing an azido function is grafted onto a saccharide, 30 a peptide, 31 or a polymeric chain. 32 Here we report the synthesis of oligosaccharide tags bearing azido and alkyne termini which can be used to label oligosaccharides with alkyne or azido termini, respectively.…”