Ru-Catalyzed Enantioselective Hydrogenation of Diaryl 1,4-Diketones: Synthesis of Chiral 1,4-Diarylbutane-1,4-Diols

Asymmetric hydrogenation of diaryl 1,4-diketones was achieved by using <i>trans</i>-RuCl₂[(<i>S</i>)-BINAP)]­[(<i>S</i>)-Daipen] as the catalyst and the reaction gave rise to excellent enantio- and diastereoselectivities (up to >99% <i>ee</i> and <i>de</i>). This procedure provides a convenient and efficient synthetic method for chiral 1,4-diarylbutane-1,4-diols, which are important intermediates for a variety of chiral auxiliaries and ligands.