Synthesis of C‐Oligosaccharides through Versatile C(sp(3))−H Glycosylation of Glycosides

C‐oligosaccharides are pharmacologically relevant because they are more hydrolysis‐resistant than O‐oligosaccharides. Despite indisputable advances, C‐oligosaccharides continue to be underdeveloped, likely due to a lack of efficient and selective strategies for the assembly of the interglycosidic C−C linkages. In contrast, we, herein, report a versatile and robust strategy for the synthesis of structurally complex C‐oligosaccharides via catalyzed C(sp(3))−H activations. Thus, a wealth of complex interglycosidic (2→1)‐ and (1→1)‐C‐oligosaccharides becomes readily available by palladium‐catalyzed C(sp(3))−H glycoside glycosylation. The isolation of key palladacycle intermediates and experiments with isotopically‐labeled compounds identified a trans‐stereoselectivity for the C(sp(3))−H glycosylation. The glycoside C(sp(3))−H activation manifold was likewise exploited for the diversification of furanoses, pyranoses and disaccharides.