Novel neutral phosphinite bridged dinuclear ruthenium(II) arene complexes and their catalytic use in transfer hydrogenation of aromatic ketones: X-ray structure of a new Schiff base, N3,N3 '-di-2-hydroxybenzylidene-[2,2 ']bipyridinyl-3,3 '-diamine


AYDEMİR M., DURAP F., BAYSAL A., MERİÇ N., Buldag A., Guemguem B., ...Daha Fazla

JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL, cilt.326, ss.75-81, 2010 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 326
  • Basım Tarihi: 2010
  • Doi Numarası: 10.1016/j.molcata.2010.04.010
  • Dergi Adı: JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
  • Sayfa Sayıları: ss.75-81

Özet

A novel Schiff base N3,N3'-di-2-hydroxybenzylidene-[2,2']bipyridinyl-3,3'-diamine, 1 was synthesized from condensation of salicylaldehyde with 3,3'-diamino-2,2'-bipyridine. Reaction of 1 with two equivalents of PPh(2)Cl in the presence of Et(3)N proceeds in toluene to give N3,N3'-di-2-(diphenylphosphino)benzylidene-[2,2']bipyridinyl-3,3'-diamine, 2 in quantitative yield. Ruthenium(II) dimers [Ru(eta(6)-arene)(mu-Cl)]Cl](2) readily react with phosphinite ligand [(Ph(2)PO)(2)-C(24)H(16)N(4)], 2 in toluene at room temperature, to afford the neutral derivatives [C(24)H(16)N(4){OPPh(2)-Ru(eta(6)-arene)Cl(2}2)] {arene: benzene 3, p-cymene, 4}. All the complexes were fully characterized by analytical and spectroscopic methods. (31)P-{(1)H} NMR, (1)H-(13)C HETCOR or (1)H-(1)H COSY correlation experiments were used to confirm the spectral assignments. Molecular structure of the Schiff base, 1 was also determined by X-ray single crystal diffraction study. The catalytic activity of complexes 3 and 4 in the transfer hydrogenation of acetophenone derivatives was tested. Stable ruthenium(II)-phosphinite complexes were found to be efficient catalysts in the transfer hydrogenation of aromatic ketones in excellent conversions up to 99% (up to 530 per hour) in the presence of iso-PrOH/KOH. (C) 2010 Elsevier B.V. All rights reserved.