A dinuclear copper(i) thiodiacetate complex as an efficient and reusable ‘click’ catalyst for the synthesis of glycoconjugates

Abstract

We report herein the facile synthesis and structural characterization of a highly stable dinuclear Cu(i) complex, [(PPh)Cu(μ-tda)Cu(PPh)]·6HO 1 (tda = thiodiacetate anion), in which the Cu-Cu distance is 7.197 Å. This "pre-formed" complex serves as an extremely efficient and recyclable homogeneous catalyst (2 mol%, 30 min) for CuAAC in dichloromethane solvent. The synthesis of a variety of glycoconjugates under ambient conditions is successfully achieved using 1 as a catalyst. The products are obtained in high yields and very short reaction times while complying with the "click protocols". A simpler procedure solely involving the mixing of substrates with 1 (i.e. base free and solvent free) gave the corresponding glycoconjugate in 10 min using 2 mol% of the catalyst.

Design, Synthesis and Pharmacological Evaluation of Noscapine Glycoconjugates

“…The synthesis of noscapine glycoconjugates has been achieved via two different approaches. In our first approach, we treated compound 3 with glycosyl azides or glycosyl azido alcohols 4 a‐m in presence of CuI/diisopropylethylamine in anhydrous diclhoromethane for 12–16 hours that resulted in the formation of resioselective 1,4‐disubstituted triazoles 5 a‐m in good yields, while in second approach, we proceeded the same click reaction between alkyne 3 and azide 4 using dinuclear copper(I) thiodiacetate complex [(PPh 3 ) 2 Cu(μ‐tda)Cu(PPh 3 ) 2 ].6H 2 O (Figure ) . This copper(I) thiodiacetate complex was obtained by reacting H 2 tda, triethylamine, and Cu(PPh 3 ) 2 NO 3 in a 1 : 2 : 2 molar ratio, respectively in anhydrous CHCl 3 following the literature procedure.…”

“…In our first approach, we treated compound 3 with glycosyl azides or glycosyl azido alcohols 4 a-m in presence of CuI/diisopropylethylamine in anhydrous diclhoromethane for 12-16 hours that resulted in the formation of resioselective 1,4-disubstituted triazoles 5 a-m in good yields, [24] while in second approach, we proceeded the same click reaction between alkyne 3 and azide 4 using dinuclear copper(I) thiodiacetate complex [(PPh 3 ) 2 Cu(μ-tda)Cu (PPh 3 ) 2 ].6H 2 O (Figure 2). [25] This copper(I) thiodiacetate complex was obtained by reacting H 2 tda, triethylamine, and Cu (PPh 3 ) 2 NO 3 in a 1 : 2 : 2 molar ratio, respectively in anhydrous CHCl 3 following the literature procedure. CuÀ Cu distance in complex [(PPh 3 ) 2 Cu(μ-tda)Cu(PPh 3 ) 2 ].6H 2 O (tda = thiodiacetate anion) is 7.197 Å, [25] where this complex serves as an efficient homogeneous catalyst for the CuAAC reaction in dichloromethane.…”

“…This copper(I) thiodiacetate complex was obtained by reacting H 2 tda, triethylamine, and Cu(PPh 3 ) 2 NO 3 in a 1 : 2 : 2 molar ratio, respectively in anhydrous CHCl 3 following the literature procedure. Cu−Cu distance in complex [(PPh 3 ) 2 Cu(μ‐tda)Cu(PPh 3 ) 2 ].6H 2 O (tda=thiodiacetate anion) is 7.197 Å, where this complex serves as an efficient homogeneous catalyst for the CuAAC reaction in dichloromethane. Thus, we further explore the synthesis of target noscapine glycoconjugatated 1,4‐disubstituted triazoles 5 with an aid of dinuclear copper(I) thiodiacetate complex under ambient conditions, where respective regio‐selective triazoles were obtained in an excellent yields and in short reaction time (30 min to one hour) with a great ease (Scheme 2).…”

Dinuclear Copper(I) Thiodiacetate Complex-Mediated Expeditious Synthesis of the Chlorine-Containing Cyclen-Cored 36-Glucose-Coated Glycodendrimer

“…Compound 8 was synthesized as reported in the literature, and the spectral data were well elucidated. [36].…”

“…Towards this end, a number of promising such catalysts such as mono-and dinuclear heteroleptic Cu(I) dithio-PPh3 complexes [32], di-and mononuclear heteroleptic Cu(I) dixanthate/xanthate-phosphine complexes [33], heteroleptic [Cu(PPh 3 ) 2 (β-oxodithioester)] complexes [34], thiocarboxylate complexes, and cubane-based hydrosulfide complexes of Cu(I) [35] were displayed efficient catalytic activities for the click conjugation with carbohydrates. Among all, a highly stable Cu(I) catalyst [(PPh 3 ) 2 Cu(μ-tda) Cu(PPh 3 ) 2 ].6H 2 O with significant catalytic activity has been copiously exploited for the thriving construction of regioselective 1,4-disubstituted dendritic architectures [36].…”