Direct construction of aryl amide N-glycosides from glycosyl oxamic acids via photoredox palladium-catalyzed aminocarbonylations

Conventional amide N-glycosylation reactions typically follow a two-electron process. Despite advancements, these methods still face challenges, including the need for high temperatures, stoichiometric amounts of strong Lewis acids, and issues with chemical and stereoconfiguration stability. Precise control over the anomeric C-N bond formation remains difficult with these methods, limiting the use of glycals to specialized labs with expertise in carbohydrate chemistry. Here, we present a synergistic photoredox/Pd-catalyzed approach for aminocarbonylation of glycosyl oxamic acids with (hetero)aryl bromides, allowing for the synthesis of aryl N-amide glycosides under mild conditions. This method uniquely combines single- and two-electron strategies, using glycosyl oxamic acids as traceless carbamoyl radical precursors. By bypassing the direct anomeric C-N bond formation, our approach provides an efficient alternative for the modular synthesis of aryl amide N-glycosides.