Recent advances in transition-metal-catalyzed glycosyl cross-coupling reactions

As one of the effective strategies for carbohydrate synthesis, chemical synthesis can precisely control the structure of sugar chains, thus establishing the structure-activity relationship of complex sugars. The precise construction of glycosidic bonds is a long-standing challenge of stereo-controlled synthesis of carbohydrates. Therefore, research on developing stereoselective glycosylation to access carbohydrate mimics has received considerable attention from chemists, and this has led to remarkable progress and achievement in this field. In recent years, transition-metal-catalyzed glycosylation reactions involving anomeric C(sp3)-metal bond formation have emerged as a powerful tool for the synthesis of various glycosides and glycoconjugates due to their versatility, efficiency, and stereoselectivity. In this review, we highlight and discuss remarkable advances (from January 2017 to July 2022) in this rapidly expanding area. This review aims to provide timely illumination and beneficial guidance for the application of transition-metal catalysis in glycosyl cross-coupling reactions and endeavors to inspire further progress in this emerging area.