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 (Pr-i, Ph) were employed to synthesize a series of cobalt(II) complexes ([LCoBr2], [L2CoBr](PF6) and [L'2CoBr](PF6)). The latter were obtained in high yield and characterized among others by X-ray analysis and elemental analysis. Complex [L2CoBr](PF6) 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 Ph2SiH2 in mild conditions and was efficient with aliphatic or aromatic ketones giving moderate to excellent yields of the corresponding silylated ether.