Enabling technologies applied to glycosylation

The chapter deals with new activation conditions and technologies for glycosylation reactions with stereochemical and large-scale control. We describe new green activation conditions (electrochemistry, mechanochemistry, biocatalysis, continuous flow and photocatalysis) developed for increasing the efficiency of the chemical reactions and applied to glycosylation. Mechanochemistry and electrochemistry were applied to the synthesis of C-, N-, O-glycosides and nucleoside analogues. These conditions can be developed iteratively, without protection from glycosylated substrates. We also describe the use of continuous flow allowing better selectivity, shorter reaction times and easier scale-up, for example in the case of Remdesivir synthesis. Biocatalyzed reactions and photon-starved large-scale photo-redox reactions can be conducted under these conditions. Finally, automated synthesis is definitely entering glycomics. The opportunities for glycosylation provided by these new technologies are significant and respond to the increasing complexity of glycosidic targets.