Efficient redox isomerization of allylic alcohols under mild conditions catalyzed by arene-ruthenium(II) complexes

The catalytic activity of the arene-ruthenium(II) complexes [RuCl2(eta(6)-p-cymene)(L)] (L = P(OPh)(3), P(OMe)(3), P(OEt)(3), PPh3, P(p-C6H4OMe)(3), PMe2Ph, PMe3, PEt3, PCy3) in the isomerization of allylic alcohols into the corresponding saturated ketones has been investigated, the best performances being obtained using [RuCl2(eta(6)-p-cymene){P(OEt)(3)}]. This compound has proven to be able to catalyze the transformation of poorly reactive substrates of the type R(1)CHdCHCH(OH)R-2 and (RCH)-C-1=C(R-2)CH(OH)R-3 (R-1, R-2, R-3 not equal H) under very smooth conditions.