Cobalt Complexes Supported by Phosphinoquinoline Ligands for the Catalyzed Hydrosilylation of Carbonyl Compounds.

P,N phosphinoquinoline based ligands differing by the nature of the phosphorus substituent ( i Pr, Ph) were employed to synthesize a series of cobalt(II) complexes ([LCoBr 2 ], [L 2 CoBr](PF 6 ) and [L' 2 CoBr](PF 6 )). The latter were obtained in high yield and characterized among others by X-ray analysis and elemental analysis. Complex [L 2 CoBr](PF 6 ) showed a very good catalytic activity for the hydrosilylation of various ketones. The catalysis proceeds at a low catalytic loading (1 mol %) with only 1 equivalent of Ph 2 SiH 2 in mild conditions and was efficient with aliphatic or aromatic ketones giving moderate to excellent yields of the corresponding silylated ether.