Tetranuclear assembly of palladium(II): Catalyst for C–C coupling reactions

The 2-((2-benzylamino)phenyldiazenyl)phenol, H2OL [where H2OL = ArOHN = NC6H4N(H)CH2(C6H5); Ar = C6H5 (for H2OL1), p-MeC6H4 (for H2OL2) or p-ClC6H4 (for H2OL3)], ligands were prepared by the reaction of the appropriate 2-((2-hydroxyaryl)azo)anilines with benzyl bromide. The reactions of Na2PdCl4 with H2OL afforded tetranuclear Pd(II) complexes of the composition [Pd(OL)]4. The ligands bind palladium(II) in a tridentate (N, N, O) fashion. The X-ray structure of [Pd(OL1)]4 was determined to confirm the characterization. The newly synthesized [Pd(OL1)]4 complex was utilized as a catalyst for the Suzuki and Heck reaction for a variety of substrates.

Some new (O,N,N) donor ligands and their tetranuclear palladium(II) complexes have been synthesized and characterized. The catalytic behavior of one tetranuclear complex toward C–C coupling reactions has also been studied.Figure optionsDownload as PowerPoint slide