Kinetic Resolution of Racemic Secondary Alcohols by Ru^II‐Catalyzed Hydrogen Transfer

Abstract

COMMUNICATIONS 243 K. 4282 Reflections were independent and unique, and 2162 with I > 3 OOa(1) (28,,, = 55") were used for the structure solution. The hydrogen atoms at NI and at Ru could be localized and were refined isotropically, and the remaining hydrogen atoms were calculated from ideal geometries. fixed, and included in thecalculation ofthe structural factor. R = 0.050, Rw = 0.067, w' = (o'(E) +0.0025F2)-'. Rigaku AFC7R diffractometer (graphite monochromator, MoK.). The structures were solved with PATTY and DIRDIF94 [Sb]. Crystallographic data (excluding structure factors) for the structures reported in this paper have been deposited with the Cambridge Crystallographic Data Centre as supplementary publication no. . Copies of the data can be obtained free of charge on application to The Director, CCDC, 12 Union Road, Cambridge CB2 lEZ, UK (fax' Int. code +(1223)336-033;

The Chemistry of Vicinal Diamines

“…Recently Noyori et al reported that efficient kinetic resolution of racemic alcohols could be achieved by hydrogen transfer catalyzed by a diamine ± Ru II complex, [70] and Jacobsen et al described the kinetic resolution of racemic, terminal epoxides by means of a hydrolysis catalyzed by chiral (salen) ± cobalt complexes, which afforded both the unreacted substrates and the products (1,2-diols) in high enantiomeric excess. [71] …”

Industrial Methods for the Production of Optically Active Intermediates

“…An oxidative variant has also been described. [146] The heterogeneous asymmetric hydrogenation of Blaser and Studer, [147] which provides a precursor for ACE inhibitors, was operated on a ton scale at Ciba-Geigy. A cinchona-doped platinum catalyst was used for the hydrogenation of the ketoester 173 to the 4-phenylhydroxybutyrate 174 (Scheme 68).…”

Direct and Transfer Hydrogenation of Ketones and Imines with a Ruthenium N-Heterocyclic Carbene Complex

“…We investigated the oxidation of a series of secondary alcohols into ketones by transfer hydrogenation using acetone as the hydrogen acceptor and in the absence of base, unlike most other catalytic systems (Scheme 3). [7] Reactions were performed at 50 8C in resealable NMR tubes under argon using 2 mol % of catalyst 1 and 5 equivalents of acetone. The reaction progress was followed by 1 H NMR spectroscopy for 12 hours.…”