Synthesis of Mononuclear Cyclopalladated Complexes Containing Tertiary Phosphines (Pph2et, P(4-Mec6h4)3), Triphenylarsine, Piperidine, Benzylamine, and Pyridine

Abstract

When C6H4CH2NH2 and Pd(OAc)2 are reacted in a 1:1 molar ratio in benzene, toluene or acetonitrile at 60–80°C the ortho-metalated complex [Pd(μ-OAc)(C6H4CH2NH2-κ2-C,N)]2 (1) is obtained. Complex 1 reacts with NaCl or KCl to afford the complex [Pd(μ -Cl)(C6H4CH2NH2−κ2-C,N)]2 (2). PPh2Et, P(p-tolyl)3, AsPh3, piperidine, and pyridine split the chloride bridge in complex 2 to give [PdCl(C6H4CH2NH2−κ 2-C,N)L] (L = PPh2Et (3a), P(p-tolyl)3 (3b), AsPh3 (3c), piperidine (3d), C6H4CH2NH2 (3e), pyridine (3f)). Complex 3f reacts in THF at room temperature with thallium triflate (TlTfO) and pyridine (molar ratio 1:1:1) to afford complex [Pd(C6H4CH2NH2)(py)2]TfO (4). Infrared and NMR spectroscopy allow the unambiguous characterization of these products. The molecular structure of [Pd(C6H4CH2NH2)(py)2]TfO (4) in the crystal was determined.