1277191-54-4Relevant academic research and scientific papers
Coordination chemistry of the (η6-p-cymene)ruthenium(II) fragment with bis-, tris-, and tetrakis(pyrazol-1-yl)borate ligands: Synthesis, structural, electrochemical, and catalytic diastereoselective nitroaldol reaction studies
Pettinari, Claudio,Marchetti, Fabio,Cerquetella, Adele,Pettinari, Riccardo,Monari, Magda,Mac Leod, Tatiana C. O.,Martins, Luisa M. D. R. S.,Pombeiro, Armando J. L.
, p. 1616 - 1626 (2011)
Novel [Ru(η6-p-cymene)(κ2-L)X] and [Ru(η6-p-cymene)(κ3-L)]X?nH2O complexes (L = bis-, tris-, or tetrakis-pyrazolylborate; X = Cl, N3, PF6, or CF3SO3) are prepared by treatment of [Ru(η6-p-cymene)Cl2]2 with poly(pyrazolyl)borate derivatives [M(L)] (L in general; in detail L = Ph 2Bp = diphenylbis(pyrazol-1-yl)borate; L = Tp = hydrotris(pyrazol-1- yl)borate; L = pzTp = tetrakis(pyrazol-1-yl)borate; L = Tp4Bo = hydrotris(indazol-1-yl)borate, L = Tp4Bo,5Me = hydrotris(5- methylindazol-1-yl)borate; L = TpBn,4Ph = hydrotris(3-benzyl-4- phenylpyrazol-1-yl)borate; M = Na, K, or Tl) and characterized by analytical and spectral data (IR, ESIMS, 1H and 13C NMR). The structures of [Ru(η6-p-cymene)(Ph2Bp)Cl] (1) and [Ru(η6-p-cymene)(Tp)Cl] (3) have been established by single-crystal X-ray diffraction analysis. Electrochemical studies allowed comparing the electron-donor characters of Tp and related ligands and estimating the corresponding values of the Lever EL ligand parameter. The complexes [Ru(η6-p-cymene)(κ2-L)X] and [Ru(η6-p-cymene)(κ3-L)]X?nH2O act as catalyst precursors for the diastereoselective nitroaldol reaction of benzaldehyde and nitroethane to the corresponding β-nitroalkanol (up to 82% yield, at room temperature) with diastereoselectivity toward the formation of the threo isomer.
