Click chemistry methods are used to synthesize libraries of substances with high chemical diversity, which is important when developing new drugs. These reactions are necessary for introduction of labels (for example, fluorescent ones) into biological macromolecules, proteins, and DNA molecules. This is used in biological and medical research.

A chemist from RUDN University Rafael Luque and his colleagues have developed a series of catalysts with copper ions attached to the surface of silica gel particles using cyclic cyclodextrin oligosaccharide. Cyclodextrin consists of seven glucose molecules closed in a cycle. Inside the cycle there is a container that can hold the copper ion and increase its catalytic activity. Ultrasound irradiation was used to facilitate the binding of cyclodextrin to the surface of silica gel.

The effectiveness of the created catalysts was evaluated on a model reaction of phenylacetylene with benzylazide. The researchers managed to achieve a yield of the reaction product of more than 99%. The yield with copper (II) acetate was 14%, and in the case of copper (II) sulfate, the reaction did not occur at all. The method for producing the catalyst is simple, safe for the environment, and cheap; its use does not require to add reducing agents or oxygen-free conditions. The catalysts can find application in the pharmaceutical industry and in biomedical research.