Syntheses, structures and immobilization of arene-ruthenium complexes bearing phosphine ligands with methoxysilyl groups

Condensation of 3-aminopropyltrimethoxysilane and chlorodiphenylphosphine in the molar ratio of 1: 1 and 1: 2 in the presence of Et3N in toluene afforded aminophosphine (CH3O)(3)Si(CH2)(3)NHPPh2 (L1) and bisphosphinoamine (CH3O)(3)Si(CH2)(3)N(PPh2)(2) (L2) with methoxysilyl groups, respectively. Treatment of [(eta(6)-C6H6)RuCl2](2) with L1 in refluxing tetrahydrofuran gave a mononuclear ruthenium phosphine complex [(eta(6)-C6H6)RuCl2(kappa(1)-P-L1)] (1). Reaction of [(eta(6)-p-cymene)RuCl2](2) with L2 under the similar condition gave a dinuclear ruthenium phosphine complex [(eta(6)-p-cymene)Ru(mu-Cl)(RuCl)-Ru-3(kappa(2)-P,P-L2)] (2). Complexes 1 and 2 were characterized by microanalyses, IR and NMR spectroscopies, and their structures were also established by single-crystal X-ray diffraction. Immobilization of complexes 1 and 2 on SBA-15, and characterization of these hybrid heterogeneous catalysts were studied by transmission electron microscopy (TEM), IR and low pressure N-2 adsorption/desorption measurement. The heterogeneous catalysts were also briefly tested for transfer hydrogenation of acetophenone. (C) 2019 Elsevier B.V. All rights reserved.