Ruthenium-Catalyzed Transfer Hydrogenation of Amino- and Amido-Substituted Acetophenones

The ruthenium-catalyzed transfer hydrogenation of electron-rich amino-substituted acetophenones is reported. Variation of the reductant, ligands, base, and solvent allowed reaction optimization. A key discovery was the use of 1,4-butanediol as an irreversible reducing agent, which significantly improved the conversion. A range of amino- and amido-substituted aryl ketones were explored, and they all gave the corresponding alcohols in good yield, which demonstrates the wider applicability of this process.