| Abstract
| - This Account covers the design of Ru catalysts and ligands. Twoclasses of chiral phosphine ligands are prepared: the electron-richtrans-2,4-substituted phosphetanes, readily available from opticallypure 1,3-diol cyclic sulfates, and atropoisomeric ligands (SYNPHOS,MeO-NAPhePHOS, bearing heterotopic biaryl moieties, and a chiralwater-soluble diguanidinium binaphthyl diphosphine, Digm-BINAP). Applications of these ligands to rhodium- and ruthenium-mediated hydrogenation of ketones and olefins have been reportedwith high enantioselectivities. The recognition abilities of Ru-SYNPHOS for a wide range of ketones is superior to those observedwith BINAP, MeO-NAPhePHOS, and MeO-BIPHEP. Several biologically active compounds have been prepared through dynamickinetic resolution. This work gives access to a number of highlyactive catalysts of the type [Ru(biphosphane)(H)(η6-cot)]BF4. Thesecatalysts have demonstrated their utility in the enantioselectivehydrogenation of the tetrasubstituted cyclopentenone “dehydrodione”, which leads to the commercially important perfume component Paradisone (Firmenich).
|
