Novel Catalytic Hydrogenolysis of Trimethylsilyl Enol Ethers by the Use of an Acidic Ruthenium Dihydrogen Complex

The heterolytic cleavage of H ₂ is the key to the novel catalytic hydrogenolysis of trimethylsilyl enol ethers catalyzed by RuCl(η²-H₂)(dppe)₂]OTf (dppe = 1,2-bis(diphenylphosphanyl)ethane, OTf = trifluoromethanesulfonate), which results in the formation of a ketone and Me₃SiH (see scheme). In addition, the stoichiometric, ruthenium-assisted protonation of a prochiral lithium enolate with H₂ gave a chiral ketone with high enantioselectivity (up to 75 % ee).