Ruthenium-Catalyzed Straightforward Synthesis of 1,2,3,4-Tetrahydronaphthyridines via Selective Transfer Hydrogenation of Pyridyl Ring with Alcohols

Through a ruthenium-catalyzed selective hydrogen transfer coupling reaction, a novel straightforward synthesis of 1,2,3,4-tetrahydronaphthyridines from o-aminopyridyl methanols and alcohols has been developed. The synthetic protocol proceeds in an atom- and step-economic fashion together with the advantages of operational simplicity, broad substrate scope, production of water as the only byproduct, and no need for external reducing reagents such as high pressure H2 gas, offering a highly practical approach for accessing this type of structurally unique products.