A Kumada Coupling Catalyst, [Ni{(Ph2P)2N(CH2)3Si(OCH3)3-P,P }Cl2], Bearing a Ligand for Direct Immobilization Onto Siliceous Mesoporous Molecular Sieves

0444673 - ÚFCH JH 2016 RIV DE eng J - Journal Article
Stamatopoulos, I. - Giannitsios, D. - Psycharis, V. - Raptopoulou, C. P. - Balcar, Hynek - Zukal, Arnošt - Svoboda, J. - Kyritsis, P. - Vohlídal, J.
A Kumada Coupling Catalyst, [Ni{(Ph2P)2N(CH2)3Si(OCH3)3-P,P }Cl2], Bearing a Ligand for Direct Immobilization Onto Siliceous Mesoporous Molecular Sieves.
European Journal of Inorganic Chemistry. Roč. 2015, č. 18 (2015), s. 3038-3044. ISSN 1434-1948. E-ISSN 1099-0682
R&D Projects: GA ČR GAP108/12/1143
Institutional support: RVO:61388955
Keywords : homogenous catalysis * heterogeneous catalysis * cross coupling
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 2.686, year: 2015

The ligand-exchange reaction between [Ni(PPh3)2Cl2] and (Ph2P)2N(CH2)3Si(OCH3)3 afforded the novel NiII complex [Ni{(Ph2P)2N(CH2)3Si(OCH3)3-P,P′}Cl2] (1) in which the square-planar NiP2Cl2 coordination sphere contains a four-membered Ni–P–N–P ring. Comparison of the structure of 1 and related NiII square-planar or Ni0 tetrahedral complexes containing similar P–N–P ligands shows that the magnitude of the P–Ni–P angle is controlled by the presence of the Ni–P–N–P ring, irrespective of the geometry of the nickel coordination sphere. Direct anchoring of 1 onto SBA-15 molecular sieves through the trimethoxysilyl end-group of the ligand afforded heterogeneous catalyst 1/SBA-15. Both 1 and 1/SBA-15 catalyze Kumada cross-coupling reactions, exhibiting similar activity and a slightly higher product selectivity than the [Ni{Ph2P(CH2)3PPh2-P,P′}Cl2] and [Ni{(Ph2P)2N-(S)-CHMePh-P,P′}X2] (X = Cl, Br) complexes described in the literature. The Grignard reagent employed is likely to induce leaching of the catalyst, which retains its activity in solution.
Permanent Link: http://hdl.handle.net/11104/0247210