A Journey from Traditional to Photoredox-Induced C-Glycosylations

Abstract

C-Glycosylation is regarded as one of the most powerful tools for synthesizing biologically potent molecules, where specific control over the anomeric selectivity has remained a major synthetic hurdle. Recently discovered approaches of radical glycosylations through metallo- and organo-catalyzed photoredox reactions has provided robust and sustainable routes towards stereoselective C-glycosylations using various glycosyl radical precursors. The discovery of new and effective glycosyl radical precursors has opened a new avenue for synthesizing C-aryl glycosides, C-alkyl glycosides, C-nucleosides, 2-deoxy sugar, glycoamino acids, glycopeptides, and other glyco-conjugates. These strategies are advantageous due to their mild reaction conditions, excellent functional group tolerance, and low catalyst loading. In this chapter, we will highlight all the recent discoveries of the glycosyl radical precursor and the development towards synthesizing C-glyco­sides.