For applications in aqueous media, sulfonated tetrahydrosalen (sulfosalan, HSS) was synthesized by sulfonation of tetrahydrosalen in fuming sulfuric acid. The Pd (II) complex of this ligand,[Pd (HSS)], showed outstanding activity in hydrogenation and redox isomerization of allylic alcohols in homogeneous aqueous solutions or in aqueous–organic biphasic systems (for oct-1-en-3-ol TOF (hydrogenation)= 1580 h–1, TOF (redox ...