Catalytic behavior of wool-Pt complex in asymmetric hydrogenation of ketones

A wool-Pt complex was prepared by the reaction of wool with chloroplatinic acid in ethanol solution, and was found to be useful as a chiral catalyst f or the asymmetric hydrogenation of some ketones to corresponding chiral alc ohols, such as 3-methyl-2-butanone to (R)-3-methy-2-butanol, 4-methyl-2-pen tanone to (R)-4-methyl-2-pentanol, acetophenone to (R)-1-phenylethanol and propiophenone to (R)-1-phenyl-1-puopanol at 30 degrees C and under an atmos pheric hydrogen pressure. In the case of hydrogenation of 3-methyl-2-butanone to (R)-3-methyl-2-butan ol, when a proper content of Pt in the wool-Pt complex was selected, the yi eld and optical yield amounted to about 100% respectively, and the wool-Pt complex catalyst could be reused without any change in the optical catalyti c activity. Wool is a very cheap natural bio-polymer ligand, and Wool-Pt complex is ver y easy to prepare, and it is a very active, enantioselective and stable chi ral catalyst for asymmetric hydrogenation of some ketones. (C) 1999 John Wi ley & Sons, Ltd.