Chiral phosphonite, phosphite and phosphoramidite eta(6)-arene-ruthenium(II) complexes: application to the kinetic resolution of allylic alcohols

The synthesis and characterization of chiral arene-ruthenium complexes [RuCl2(eta(6)-arene){(R)-PR-(binaphthoxy)}] (arene = benzene (1), p-cymene (2), mesitylene (3); R = Ph (a), OPh (b), piperidyl (c)) are described. Derivatives 1-3 have been employed to promote the kinetic resolution of allylic alcohols through a redox-isomerization process. As a general trend, the best selectivities are attained with the more sterically hindered catalysts i.e. those containing p-cymene or mesitylene ligands.