Stereoselective synthesis of oligosaccharides and glycoconjugated Lanthanide complexes with bioactive properties

This study addresses two distinct research directions. The first part focuses on the development of innovative glycosylation methodologies based on chiral vinyl epoxides for the stereoselective synthesis of oligosaccharides. These highly reactive intermediates enable a catalyst-free glycosylation process, providing complete regio- and stereocontrol through interactions between the nucleophile and the oxirane moiety. On this basis, a rapid and versatile one-pot strategy has been developed for the reiterative assembly of β-1,4-D-Gulo and α-1,4-D-Manno oligosaccharides. The use of allylic alcohols as both glycosyl acceptors and initiators allows controlled chain elongation in a single reaction vessel, eliminating the need for intermediate purification steps and ensuring high synthetic efficiency. The second part is devoted to the design and synthesis of glycoconjugates for biomedical imaging applications. In particular, Lanthanide(III) complexes functionalized with carbohydrate moieties have been developed to enhance selective targeting of cancer cells. These systems exhibit favorable photophysical properties, including long luminescence lifetimes and high emission intensity, making them suitable as imaging probes. Biological evaluation, both in vitro and in vivo using zebrafish models, demonstrated good biocompatibility, efficient biodistribution, and preferential accumulation in tumor tissues. Overall, this work highlights the potential of glycosylation-based approaches in advancing both synthetic carbohydrate chemistry and the development of functional probes for biomedical applications.