Ruthenium(II)-catalyzed deoxygenation of ketones.

The classical Wolff-Kishner reduction plays a key role in organic synthesis to convert carbonyl functionalities into methylene groups; however, it generally requires harsh reaction conditions and a strategy with wider applications demands further development. Herein, a ruthenium-catalyzed Wolff-Kishner type reduction of ketones is developed with 31 examples under mild conditions. This strategy tolerates aryl and alkyl ketones with reactive functional groups including halogens, hydroxyls, carboxylic acid, unsaturated functional groups, and so on. The corresponding methylene products were obtained in 32% to 95% yields while using water or methanol as solvents.