Hydrosoluble complexes bearing tris(Pyrazolyl)methane sulfonate ligand: Synthesis, characterization and catalytic activity for henry reaction

The catalytic activity of the water-soluble scorpionate coordination compounds [Cu(κNN’O-Tpms)2] (1), [Mn(Tpms)2] (2) and Li[FeCl2(κ-NN’N’’-Tpms)] (3) [Tpms = tris(pyrazolyl)methane sulfonate, O3SC(pz)3⁻], were studied towards the (Henry) reaction between benzaldehyde and nitromethane or nitroethane in aqueous medium to afford, respectively, 2-nitro-1phenylethanol or 2-nitro-1-phenylpropanol, the latter in the syn and the anti diastereoisomeric forms. Complex 1 exhibited the highest activity under the optimum experimental conditions and was used to broaden the scope of the reaction to include several aromatic aldehydes achieving yields up to 94%.