HOMOGENEOUS HYDROGENATION OF KETONES USING CHROMIUM HEXACARBONYL AS CATALYST PRECURSOR IN THE PRESENCE OF BASES

Article abstract of DOI:10.1016/0022-328X(85)87367-8

The hydrogenation of ketones at 100-120 degC and 100 bar H2 is catalyzed by Cr(CO)6 in methanol solution in the presence of NaOMe.The reaction is inhibited by CO and the rate increases with increasing H2 pressure and base: chromium ratio.In a stoichiometric reaction at 75 degC, HCr(CO)5^- hydrogenates ketones to alcohols, while forming Cr2(CO)10^2-.A catalytic cycle involving alkoxychromium complexes, R2CHOCr(CO)5^-, as intermediates is proposed.Similar hydrogenation catalysts are obtained from W(CO)6 and Mo(CO)6; the latter is the most active and may be used even at 70-80 degC.