Mono‐Amination of Methyl‐α‐d‐glucoside via Borrowing Hydrogen with Recyclable Ru/C

This study presents a highly efficient and sustainable method for the mono‐amination of unprotected sugar derivatives using a commercially available Ru/C heterogeneous catalyst under borrowing hydrogen (BH) conditions. Unlike conventional approaches, this strategy avoids sugar protection steps, C─C bond cleavage, and external additives, enabling direct C─N bond formation. Using methyl‐α‐ d ‐glucoside as a model, the process achieved high selectivity for secondary amines with yields up to 79%. The Ru/C catalyst proved robust and recyclable, maintaining both activity and metal content over 10 cycles. The reaction displayed broad compatibility with various aliphatic amines, and its selectivity could be tuned by adjusting solvent and hydrogen pressure. Importantly, the sugar backbone remained intact—an improvement over many previous BH methods that caused degradation. DFT calculations provided mechanistic insights, showing that mono‐amination facilitates dehydrogenation while minimizing overamination. This is attributed to a key role of Ru─H interactions in guiding the reaction pathway. Overall, the study demonstrates a rare and selective amination at nonanomeric positions of unprotected sugars using a heterogeneous catalyst. These results establish a new standard for green, atom‐efficient synthesis of nitrogen‐containing sugar derivatives and open promising routes for functional carbohydrate development from renewable resources.