ONO pincer palladium (II) complexes featuring furoylhydrazone ligands: Synthesis, characterization and catalytic activity towards Suzuki-Miyaura coupling reaction

摘要

Four new palladium pincer complexes incorporating ONO type furoylhydrazone ligands have been prepared in good yields. These palladium complexes were structurally characterized by elemental analysis, infrared, H-1- and C-13-NMR spectra. X-ray single crystal analyses of Pd1-Pd4 revealed that the metal center adopted a slightly distorted square planar geometry in which the hydrazone bound the metal ion via the phenolic-O, azomethine-N and imidolate-O atoms. Using these ONO pincer complexes as catalyst, excellent yields of biaryls could be obtained for coupling of arylboronic acids with aryl bromides at a low catalyst loading (0.01 mol%).