176445-53-7Relevant academic research and scientific papers
Synthesis of new hemilabile amphiphilic phosphines. Complexing properties toward ruthenium(II) and catalytic activity for hydrogenation of prenal
Valls, Esteve,Suades, Joan,Mathieu, René
, p. 5475 - 5483 (1999)
New functionalized phosphines R-(C6H4)(OCH2CH2)nPPh2 {1 (R = tert-octyl, n = 1), 2 (R = tert-octyl, n? = 5), 3 (R = tert-octyl, n? = 13), 4 (R = n? -nonyl, n? = 1.4), 5 (R = n-nonyl, n? = 5), 6 (R = n-nonyl, n? = 11)}, CH3(OCH2CH2)3PPh2 (7), CH3(OCH2CH2)3PPhR (8, R = isopentyl), and HOCH2CH2(OCH2CH2)2PPhR (9, R = n-octyl) have been synthesized. These ligands contain polyether and hydrophobic groups in the same molecule and, therefore, can lead to compounds that combine hemilabile (polyether groups) and amphiphilic (hydrophobic and hydrophilic groups) properties. Complexation studies with Ru(II) have been performed, and the unusual tridentate (O, O, P) coordination mode has been characterized. The hemilabile character has been shown by evolution from the tridentate (O, O, P) coordination mode to the bidentate (O, P) and monodentate (P) after a reaction between CO and [RuCl2(8)-(PPh3)]. Dinuclear [Ru2Cl4L5] complexes have been obtained from ligands with a short polyether chain (1, 4). The catalytic selective hydrogenation of an α,β-unsaturated aldehyde (prenal) with ruthenium complexes prepared in situ from RuCl3 and ligands 1-6 has been carried out in a 2-propanol/water mixture. Conversions to prenol to the order of 90% or higher are observed with selectivity of 90-96% after 20 min at P = 30 bar and T = 50°C. The most active systems have been observed with ligands containing long polyether chains.
