Cyanosilylation of aldehydes catalyzed by lanthanide derivatives comprising arylhydrazones of β-diketones

Two known lanthanide complexes, [KLa(HL1)2{(CH3)2NCHO}2(H2O)3] (1) and [Sm(H2O)9](E-H2L2)3·2H2O (2) were prepared by reaction of lanthanum(III) and samarium(III) nitrates with potassium 3-(2-(2,4-dioxopentan-3-ylidene)hydrazinyl)-2-hydroxy-5-nitrobenzenesulfonate (KH2L1) and potassium (E,Z)-5-chloro-3-(2-(1,3-dioxo-1-phenylbutan-2-ylidene)hydrazinyl)-2-hydroxybenzenesulfonate (KH2L2), respectively. Catalytic activities of 1 and 2 were evaluated in the cyanosilylation of aldehydes with trimethylsilyl cyanide in different solvents such as tetrahydrofuran, dichloromethane or methanol. Complex 1 was found to be efficient catalyst for the cyanosilylation reaction in methanol medium at room temperature, producing cyanohydrin trimethylsilyl ethers with good yields (76–99%). © 2017 Elsevier B.V.