A Polymer-Bound Bidentate-Phosphine-Palladium Complex as a Catalyst in the Heck Arylation

摘要: Polymer-supported 1,2-bis(diisopropylphosphino)benzene Pd(II) complex 2 shows a higher level of catalytic activity than the structurally analogous monomeric 1 in Heck arylation methyl acrylate by iodobenzene. The polymer-supported has much turnover number (by more order magnitude) either or Pd(OAc){sub 2}/PPh{sub 3} at synthetically useful concentrations reagents. reaction rate is enhanced electrochemical prereduction to Pd(0). Deactivation homogeneous solution via aggregation reactive insoluble palladium metal clusters equilibration sterically blocked tetraphosphino proposed explain its soluble monomer.