Isolation and crystallographic characterization of solvate- and anion-stabilized PCP pincer complexes of palladium(II)

Pincer PCP-Pd(II) complex [PdCl(PCP)] (1) (PCP = −CH(CH2CH2PPh2)2) reacts with AgNO3 to give [Pd(NO3)(PCP)] (2). Similar reaction with AgBF4 gives the aqua complex [Pd(OH2)(PCP)][BF4] (3) and the dinuclear complex [{Pd(PCP)}2(μ-Cl)][BF4] (4) with singly bridging chloro ligand. All new complexes were characterized by NMR spectroscopy, ESI-MS and single-crystal X-ray diffraction. Complex 1 and the triflate complex [Pd(OTf)(PCP)] (5) are active towards Suzuki–Miyaura coupling between aryl bromides and phenyl boronic acid.

Graphical abstractMononuclear Pd(II) PCP complexes [PdL(PCP)][X] (PCP = −CH(CH2CH2PPh2)2; L = NO3, no X; H2O, X = BF4) with labile ligands and the singly bridging dinuclear complex [{Pd(PCP)}2(μ-Cl)][BF4] have been isolated and structurally characterized by single-crystal X-ray diffraction. The representative triflate complex and its precursor are catalytically active towards Suzuki–Miyaura coupling of selected aryl bromides.Figure optionsDownload full-size imageDownload as PowerPoint slide