A dinuclear copper(I) thiodiacetate complex as an efficient and reusable click' catalyst for the synthesis of glycoconjugates

We report herein the facile synthesis and structural characterization of a highly stable dinuclear Cu(I) complex, [(PPh3)(2)Cu(mu-tda) Cu(PPh3) (2)].6H(2)O 1 (tda = thiodiacetate anion), in which the Cu-Cu distance is 7.197 angstrom. 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.