Inorganic–organic hybrid double sulfates as catalysts of the diastereoselective nitroaldol reaction

•New hybrid materials were easily prepared from zinc(II) salt, sulfuric acid and amines.•Full structural characterization of the compounds was performed.•The synthesized compounds act as effective catalysts in the nitroaldol (Henry) reaction.

Bis(1-phenylethanaminium) disulfatotetraaquazincate(II) dihydrate (C8H12N)2[Zn(H2O)4(SO4)2]·2H2O (1), bis(1H-benzo[d]imidazolium) hexaaquazinc(II) bis(sulfate) tetrahydrate (C7H7N2)2[Zn(H2O)6](SO4)2·4H2O (2) and bis(2-methyl-1H-imidazolium) hexaaquazinc(II) bis(sulfate) dihydrate (C4H7N2)2[Zn(H2O)6](SO4)2·2H2O (3) have been synthesized and fully structurally characterized including single-crystal X-ray diffraction analysis. 1–3 are organically templated hybrid layered materials comprising aquazinc(II) and aminium cations and sulfate anions. 1–3 are effective catalysts in the asymmetric Henry reaction; 1 being the most efficient one (yields up to 85% and threo/erythro diastereoselectivity up to 89:11).

Graphical abstractNew inorganic–organic hybrid materials effectively and diastereoselectively catalyze the C–C bond formation upon nitroaldol (Henry) reaction.Figure optionsDownload full-size imageDownload as PowerPoint slide