Stereo- and chemoselective transfer hydrogenation of carbonyl groups with RuCl2(PPh3)3 and BINAP-Ru as catalysts and et3NH+H2PO2-·1,5H 2O as a hydrogen donor

Article abstract of DOI:10.1016/0040-4039(96)01476-1

Using Et₃NH+H₂PO₂^-.1.5 H₂O as a hydrogen donor, the RuCl₂(Ph₃P)₃, RuCl₂(PPh₃)₃ / C and BINAP-Ru proved highly active catalysts for transfer hydrogenation of ketones under milder conditions than other hydrogen donors. 2-Methyl-, 2-chloro-, 2-(ethoxycarbonyl)cyclohexanones and -cyclopentanones were reduced to the less stable axial alcohols in excellent diastereoisomeric excess (de: 90-100%), and the carbonyl group of α,β-unsaturated ketones was selectively reduced, in contrast with other hydrogen donors the C=C bond was reduced. Copyright