Structural Features And Catalytic Reactivity Of [Pd{(Ph2p)(2)N(Ch2)(3) Si(Och3)(3)-Kappa P,P '}I-2] And Related Complexes In Hydroalkoxycarbonylation And Suzuki-Miyaura C-C Cross-Coupling Reactions

The synthesis, as well as the structural and spectroscopic characterization of the palladium(II) complex [Pd{(Ph2P)(2)N(CH2)(3)Si(OCH3)(3)-kappa P,P'}I-2], bearing the bis(phosphino)amine ligand (P,P) = (Ph2P)(2)N(CH2)(3)Si(OCH3)(3), is described. X-ray crystallography studies revealed a square planar PdP2I2 coordination sphere, the structural features of which are compared with those of analogous nickel(II), palladium(II) and platinum(II) complexes. The three complexes [Pd(P,P)X-2], X = Cl, Br, I, along with [Pd{(Ph2P)(2)N((S)-CHPhMe)-P,P'}Cl-2] and [Pd{(Ph2PSe)(Ph2P)N((S)-CHMePh)- P,Se}Cl-2], were tested as catalysts in homogeneous hydroalkoxycarbonylation reactions. The hydroalkoxycarbonylation of styrene proved to be perfectly regioselective towards the branched ester. Complex [Pd(P,P)Cl-2] showed remarkably higher activity compared with that of [Pd(P,P)X-2], X = Br, I. Furthermore, complex [Pd(P,P)I-2] was studied as a homogeneous catalyst precursor in the Suzuki-Miyaura C-C coupling reaction between aryl bromides and phenylboronic acid. Complex [Pd(P,P)I-2] was immobilized onto STx-1 montmorillonite clay and the catalytic reactivity of the heterogenized catalyst was also investigated in both hydroalkoxycarbonylation and Suzuki-Miyaura reactions. (C) 2018 Elsevier Ltd. All rights reserved.