Mono cationic palladium(II): Synthesis, characterization and catalytic activity in Suzuki coupling

Monocationic five and four-coordinate PdII complexes have been synthesized in a facile manner involving the reaction of (COD)PdCl2 with AgPF6 and a nitrogen or phosphorus ligand. Complexes synthesized via this route are five coordinate [PdCl(2,9-Me2Phen)2]PF6 2 and four coordinate [L3PdCl]PF6 (L = PPh3, 3; P(p-Tol)3, 4; P(OEt)3; 5). ESI-MS studies at varying cone-voltage indicated ligand dissociation depending upon ligand cone-angle. A halo-bridged complex [PdCl(μ-Cl){P(p-Tol)3}]2 7 has been isolated from 4 in methanol. The cationic complexes have been screened as catalyst in Suzuki coupling involving aryl halide and phenylboronic acid. Complex 4 showed appreciable turnover.