We described a novel palladium-catalyzed C−H glycosylation of indole or tryptophan for a one-pot stereoselective synthesis of 2,3-diglycosylindoles and tryptophan-C-glycosides. In this strategy, the use of air and base-free and ligand-free conditions provided a highly efficient route to construct C-glycosides. The method can be applied to a wide range of cost-effective and convenient glycosyl chloride donors. Mechanistic studies indicated that the indole 2,3-diglycosylation sequence was C3 and then C2.

Herein, a practical and highly efficient method for visible-light-induced copper-catalyzed N-aminoquinoline-directed asymmetric C(sp 3 )−C(sp 3 )−H glycosylation was reported. At the same time, C(sp 3 )−C(sp 3 )−H glycosylation of nondeoxysugars with amino acids to construct C-glycopeptides was achieved. This approach promoted the synthesis of various C-glycopeptides and provided a new model for the synthesis of C-glycoamino acids.

We described a novel palladium-catalyzed domino procedure for the preparation of (hetero)­aryl thio/selenoglycosides. Readily available (hetero)­aryl iodides and easily accessible 1-thiosugars/1-selenosugars are utilized as the substrates. Meanwhile, 10 types of sugars are quite compatible with this reaction with good regio- and stereoselectivity, high efficiency, and broad applicability (up to 89%, 53 examples). This method enables the straightforward formation of the C­(sp2)–S/Se bond of (hetero)­aryl thio/selenoglycosides.

Construction of C(sp2)−C(sp3) bonds via regioselective coupling of C(sp2)−H/C(sp3)−H bonds is challenging due to the low reactivity and regioselectivity of C−H bonds. Here, a novel photoinduced Ru/photocatalyst-cocatalyzed regioselective cross-dehydrogenative coupling...

C-aryl glycosides are popular basic skeletons in biochemistry and pharmaceutical chemistry. Herein, ruthenium-catalyzed highly stereo-and site-selective ortho-and meta-C Ar À H glycosylation is described. A series of C-aryl pyranosides and furanosides were synthesized by this method. The strategy showed good substrate scope, and various N-heterocyclic directing groups were compatible with the reaction system. A mechanistic study suggested that the key pathway of ortho-C Ar À H glycosylation might involve oxidative addition/reduction elimination, whereas aryl meta-CÀ H glycosylation was mediated by σ-activation. Density functional theory calculations also showed that the high stereoselectivity of meta-C Ar À H glycosylation was due to steric hindrance.