Ruthenium Complexes as Efficient Catalysts for Transfer Hydrogenation Reactions

Ruthenium Complexes as Efficient Catalysts for Transfer Hydrogenation Reactions W. Baratta Dipartimento DI4A, Università di Udine, Via Cotonificio 108, 33100 Udine, Italy e-mail: walter.baratta@uniud.it The employment of selective and productive ruthenium catalysts for transfer hydrogenation (TH) and hydrogenation of carbonyl compounds is a cost-effective and environmentally benign way for the production of alcohols. Since TH is a reversible reaction, these catalysts can be used for the Oppenauer-type oxidation of alcohols and related C-H activation reactions, namely alcohol racemization and borrowing hydrogen reactions. In order to improve the catalytic activity and retard decomposition, the design of suitable metal systems based on chelating and non-innocent ligands appears crucial. The preparation of ruthenium complexes and their use as efficient catalysts for TH of ketones and aldehydes, including biomass-derived molecules (5-HMF, ethyl levulinate), Oppenauer-type alcohol oxidation, amine alkylation with alcohols and photochemical TH of carbonyl compounds are presented.