Complexation on rhodium of bidentate and potentially hemilabile phosphorous ligands

Synthesis and characterization of new RhI complexes bearing CO, PPh3 and chelating P,O- or Se,Se-ligands: Application to hydroformylation of styrene

“…The (cod) ligand of complex 2 would be easily removed, while the strong trans effect of CO could weaken the Rh-O bond in complex 3, opening the five-membered chelate ring. Similar hemilabile behavior of phosphorous chelate ligands has been considered as beneficial for hydroformylation reactions [42]. The PPh 3 group in complex 3 could also be served for an additional stabililization of the active species during the course of the metal-mediated reaction.…”

Rhodium(I) carbonyl complexes of mono selenium functionalized bis(diphenylphosphino)methane and bis(diphenylphosphino)amine chelating ligands and their catalytic carbonylation activity

“…The m(CO) values of the complexes 1 and 2 are lower relative to the analogous rhodium phosphine complexes like [Rh(CO)Cl(Ph 2 PCH 2 P(O)Ph 2 )], [Rh(CO)Cl(Ph 2 PCH 2 P(S)Ph 2 )], etc. (Table 1) [14][15][16][17]28,[31][32][33][34] indicating the metal center is rich in electron density and hence expected to show high nucleophilicity. Recently, Cole-Hamilton et al [24] reported a few electron rich complexes of the type [Rh(CO)X(PEt 3 ) 2 ] (X = Cl, Br, I) having m(CO) ca.…”

Synthesis and coordination properties of palladium(II) and platinum(II) complexes with phosphonated triphenylphosphine derivatives

“…Ambitions to use various ''field-proven'' homogeneous catalysts under aqueous and biphasic conditions made for the synthesis of a vast amount of phosphines modified by hydrophilic groups such as ammonium and phosphonium (cationic), sulfonate, phosphonate and carboxylate (anionic) or alcohol and polyether chain (neutral) [1]. Phosphines modified by phosphonate moiety [2] have been attracting attention as alternatives to well-established sulfonates [1]; several examples of their use in biphasic catalysis have been mentioned in literature [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] (e.g., Pd-catalysed electrochemical reduction of CO 2 [3], Rh-catalysed carbon-carbon double bond hydrogenation or hydroformylation [4,5], Pd-catalysed benzyl halide carbonylation [6] and Suzuki coupling [7]). A great advantage (compared with other hydrophilic moieties) is the possibility to bind the phosphonated ligand to an inert oxide surface (e.g., Al 2 O 3 ) [8], onto activated carbon surface [9] or into a layered framework, e.g., zirconium phosphonate [10,12] or zirconium phosphite/phosphonate hybrid material [13].…”

“…Such supported catalysts have been successfully tested in Rhcatalysed alkene hydroformylation [12,14], Rh-catalysed methanol carbonylation [9,15], Ru-catalysed asymmetric b-keto ester hydrogenation [4,11] or Heck reaction [13]. Several tests were also performed in organic solvents under homogeneous conditions (e.g., Pt/Sn-catalysed alkene hydroformylation [11], Rh-catalysed methanol carbonylation [16] and Rh-catalysed styrene hydroformylation [17]). …”