Abstract The activity of catalytic systems derived from the interaction between Rh (CO) 2 acac and [Ir (COD) Cl] 2, respectively, with the water soluble thioligands (L)-Cysteine (1) and (S)-Captopril (2), was tested in the aqueous biphasic hydrogenation of some representative α, β-unsaturated compounds as 2-cyclohexen-1-one (I), trans-cinnamaldehyde (V) and [3-(1, 3-benzodioxol-5-yl)-2-methylpropenal](X), precursor of the fragrance Helional®(XI). The ...