857678-55-8Relevant articles and documents
RUTHENIUM COMPLEX AND PROCESS FOR PRODUCING TERT-ALKYL ALCOHOL THEREWITH
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Page/Page column 4, (2010/11/28)
A tert-alkyl ketone, pinacolone was hydrogenated under pressurized hydrogen in the presence of a ruthenium complex (S)-1 and a base, and corresponding (S)-3,3,-dimethyl-2-butanol was thereby obtained in 100% yield and 97% ee.
Asymmetric hydrogenation of tert-alkyl ketones
Ohkuma, Takeshi,Sandoval, Christian A.,Srinivasan, Rajagopal,Lin, Quinghong,Wei, Yinmao,Muniz, Kilian,Noyori, Ryoji
, p. 8288 - 8289 (2007/10/03)
A combined system of RuCl2(tolbinap)(pica) and an alkaline or organic phosphazene base catalyzes asymmetric hydrogenation of sterically congested tert-alkyl ketones (TolBINAP = 2,2-bis(di-4-tolylphosphino)-1,1-binaphthyl, PICA = α-picolylamine). Hydrogenation with RuH(η1-BH4)(tolbinap)(pica) does not require any strong base. Alcoholic solvents strongly affect the catalytic efficiency. The reaction proceeds smoothly in ethanol under 1-20 atm of H2 and at room temperature with a substrate to catalyst molar ratio of up to 100000. Various aliphatic, aromatic, heteroaromatic, and olefinic tert-alkyl ketones are convertible to the corresponding chiral carbinols in high enantiomeric purity. Olefinic and heteroaromatic functions are left intact. Certain cyclic ketones are also usable. The mode of enantioface selection is consistent and predictable. Copyright