Ir(I)-Catalyzed C-H Glycosylation for Synthesis of 2-Indolyl-C-Deoxyglycosides

The construction of 2-deoxy-C-glycosides has gradually become a hotspot of carbohydrate chemistry in recent years. In this work, we present an efficient, regioselective, stereoselective and widely applicable strategy for the synthesis of 2-indolyl-C-deoxyglycosides via Ir(I)-catalyzed, pyridine-group-directed C-H functionalization. This method exhibits high tolerance for the functional groups of indoles and the protecting groups of carbohydrates. Moreover, this protocol has good stereoselectivity and mainly produces beta-configuration products. Gram-scale synthesis and several practical transformations were conducted for further applications. Meantime, we also explored the mechanism of this method and proposed a catalytic cycle