Efficient catalytic isomerization of allylic alcohols to carbonyl compounds with water soluble rhodium complexes

The isomerization of allylic alcohols to carbonyl compounds catalysed by water soluble transition metal complexes of Rh, Ru and Pd in a water/n-heptane biphasic system is reported. The substrates investigated are secondary or primary alcohols bearing the C=C bond in the terminal or inner position. Conversions into carbonyl compounds were quantitative except for geraniol (44% yield in citronelal). Activities up to 2 500 h(-1) and turnover numbers of more than 2 600 are reported. The differences in the observed reactivity within a family of C-1-C-8 homologous allylic alcohols is only related to thermodynamic parameters such as the solubility and L/L partition dictated by the hydrocarbon chain and not by their intrinsic reactivity. (C) 2000 Academie des sciences / Editions scientifiques et medicales Elsevier SAS (C) 2000 Academie des sciences; Editions scientifiques et medicales Elsevier SAS.