The new mixed ligand copper(II) complexes [Cu(HL)(H2O)(A)]·2H2O (1, NaH2L = sodium (Z)-2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazinyl)benzenesulfonate, A = dimethylsulfoxide, [Cu(HL)(H2O)(B)] (2, B = 1,3,4-thiadiazol-2-amine), [Cu(HL)(H2O)(Y)]·1/2CH3OH (3, C = hexamethylenetetramine) and [Cu(HR)2(H2O)2](H2L)2 (4, HR = methyl picolinimidate derived from 2-cyanopyridine) were synthesized and characterized by IR and ESI-MS spectroscopies, elemental and X-ray crystal structural analyses. These compounds act as homogenous catalysts for the cyanosilylation reaction of a variety of both aromatic and aliphatic aldehydes with trimethylsilyl cyanide affording the corresponding cyanohydrin trimethylsilyl ethers in high yields (up to 85–99 %) in methanol and at room temperature.
