Hydrogenation of α,β-unsaturated aldehydes and ketones to the unsaturated alcohols catalysed by hydridoiridium phosphine complexes

Unusual selective hydrogenation of cinnamaldehyde and benzylideneacetone to the corresponding unsaturated alcohols is catalysed by H2Ir(phosphine)4+ complexes in toluene; use of a chiral phosphine gives a 7.4% enantiomeric excess of (S)-(–)-1-phenylbut-1-en-3-ol.