Chiral ruthenium-catalyzed hydrogenation of beta-keto sulfoxides

The diastereoselective catalytic hydrogenation of beta-keto sulfoxides in t he presence of ruthenium complexes was studied. Optically pure beta-keto su lfoxides were hydrogenated in the presence of achiral catalysts leading to moderate yields and stereoselectivities. Using chiral ruthenium catalysts s uch as [(R)-MeO-BIPHEPRuBr2] and [(S)-MeO-BIPHEPRuBr2], the hydrogenation p roceeded in good yields with very high diastereoselectivity. Chirality at t he secondary centre of the beta-hydroxy sulfoxides produced was controlled by the catalysts.