The Henry reaction catalyzed by NiII and CuII complexes bearing arylhydrazones of acetoacetanilide

The new nickel coordination polymer [Ni(HL1) (CH3OH)(2)](n) (1) and co-crystal H3L1 center dot DMF (2) were obtained by reaction of NiCl2 center dot 2H(2)O with 2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene) hydrazineyl)benzoic acid (H3L1) in the presence and absence of triethylamine, respectively, in a mixture of methanol and dimethylformamide (DMF) (20:1, v/v). Reaction of CuCl2 center dot 2H(2)O with H3L1 in the presence of 2,2'(methylazanediyl)bis (ethan-1-ol) (HR) in methanol yields [Cu(HR)(2)(H2L1)(2)] (3), whereas treatment of this copper salt with sodium 2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazineyl)benzenesulfonate (NaH2L2) in a mixture of acetone and water (10:1, v/v) produces [Cu(HL2) (H2O)(2)]center dot 2(H2O)center dot {(CH3)(2)C=O} (4). Compounds 1-4 were characterized by IR and ESI-MS spectroscopies, elemental and X-ray crystal structural analyses, and tested as catalyst for the Henry reaction of aliphatic and aromatic aldehydes with nitroethane in different solvents such as acetonitrile, methanol or water. Good yields (up to 87%) and diasteroselectivities (syn/anti 77:23) were observed in the reactions catalyzed by 3 in water. (C) 2018 Elsevier B.V. All rights reserved.