Preparation and use of polymer‐supported chiral ruthenium complex catalyst

Abstract

The chiral diiminodiphosphine ligand, [(R,R)-P2N2], has been prepared by the condensation of o-(diphenylphosphino)benzaldehyde and 1,2-diaminocyclohexane. [(R,R)-P2N2] was reduced with excess NaBH4 in refluxing ethanol to afford the corresponding diaminodiphosphine ligand [(R,R)-P-2(NH)(2)]. The interaction of [(R,R)-P-2(NH)(2]) With trans-RuCl2(DMSO)(4) gave the chiral ruthenium complex [(R,R)-RuP2(NH)(2)] in 84% yield. The reaction of [(R,R)-RuP2(NH)(2]) With Poly(acrylic acid) using dicyclohexylcarbodiimine as the coupling agent, gave water soluble poly(acrylic acid salt)-supported chiral ruthenium complex [PAA-(R,R)-RuP2(NH)(2)]. These chiral ligands and ruthenium complexes have been fully characterized by microanalysis and IR, NMR spectroscopic methods. The polymer-bound ruthenium complex [PAA-(R,R)-RuP2(NH)(2)] as catalyst was used in asymmetric transfer hydrogenation of acetophenone in 2-propanol, producing the 1-phenyl-ethanol in 95% yield and 96% ee. The catalyst was reused twice with some loss of activity and enantioselectivity. Copyright (C) 2001 John Wiley Sons, Ltd

Synthesis, characterization, reactivity and antibacterial activity of new peroxovanadium(V) complexes anchored to soluble polymers

“…Chelation of a metal ion by a polymeric ligand such as polycarboxylate, as well as composition of peroxo-vanadium species have been known to be sensitive to pH of the reaction medium [47][48][49][50]. In the present study, the strategically maintained pH of ca.…”

Transfer hydrogenation of ketones catalyzed by PEG-armed ruthenium-microgel star polymers: microgel-core reaction space for active, versatile and recyclable catalysis

“…34 Even soluble polymer-supported catalysts often show lower activity than the original non-supported catalysts, owing to the steric hindrance and/or low mobility of the polymer backbone. 15,19,37 However, Ru(II)-PEG Star (C1) induced the reduction of S1 faster than the original RuCl 2 (PPh 3 ) 3 (C7) with the same and rather small amount of ruthenium ([S1]/[Ru(II)]¼1000/1), even though the star catalyst has bulky and crowded PEG side chains. This acceleration is most likely a result of the unique environment around the catalytic center, 7,9 where ruthenium catalysts are enclosed in the hydrophobic microgel core covered by the amphiphilic and polar poly(PEGMA) arms.…”

Chiral diaminodiphosphine ligands in asymmetric catalysis

“…因而负载后的手性金属络合物刚性增强、 自由度降低, 出现了一些其对映选择性反而提高的 例子 [29,30] . 我们用自行设计合成的手性双胺双膦钌 络合物, 负载于聚丙烯酸分子上, 制成聚丙烯酸键联 手性钌络合物催化剂 [31] (图 9). 手性络合物 Ru[( )-P 2 (NH) 2 ]的 31 们的广泛关注 [32] .…”

“…我们用自行设计合成的手性双胺双膦钌 络合物, 负载于聚丙烯酸分子上, 制成聚丙烯酸键联 手性钌络合物催化剂 [31] (图 9). 手性络合物 Ru[( )-P 2 (NH) 2 ]的 31 们的广泛关注 [32] . 我们也开展了手性胺膦配体在水 图 负载于聚丙烯酸的手性钌催化剂的制备 [31] 溶液中催化芳香酮不对称转移氢化的研究 [33] .…”