New polydentate ligand and catalytic properties of the corresponding ruthenium complex during sulfoxidation and alkene epoxidation.
Bis(diimine)-ruthenium complexes constitute a class of catalysts with good activity for oxidation reactions, such as sulfoxidation and epoxidation. The synthesis and the full characterization of a new ruthenium complex bearing an original pentadentate ligand (L5pyr for 2,6-bis-(6-ethyl-2,2'-bipyridyl)-pyridine) is reported. Comparison of its activity with regard to[Ru(bpy)2(CH3CN)2](2+) and [Ru(bpy)2(py)(CH3CN)](2+) during alkene and sulfide oxidation allowed us to conclude that the addition of a fifth pyridine ligand in the coordination sphere improves the efficiency of the catalyst. Moreover, under these oxidation conditions a hydroxylation of the ligand L5pyr led to a better activity than its analogue [Ru(bpy)2(py)(CH3CN)](2+), especially during epoxidation of alkenes by PhI(OAc)2.
Laboratoire de Chimie et Biochimie des Metaux, Universite Joseph Fourier, Grenoble, France. ohamelin@cea.fr
Olivier
O
Hamelin
Stéphane
S
Ménage
Florence
F
Charnay
Murielle
M
Chavarot
Jean-Louis
JL
Pierre
Jacques
J
Pécaut
Marc
M
Fontecave