Iminophosphine palladium catalysts for Suzuki carbonylative coupling reaction

Three iminophosphine ligands having soft phosphorus and hard nitrogen atoms and their Pd(II) complexes were synthesized and characterized using H-1 NMR, C-13 NMR, P-31 NMR and Fourier transform infrared spectroscopic techniques. Also, electrochemical properties of the iminophosphines and their Pd(II) complexes were investigated in acetonitrile-tetrabutylammonium perchlorate solution with cyclic and square wave voltammetry techniques. All Pd(II) complexes were evaluated as catalysts for carbonylative cross-coupling reactions of aryl iodides with phenylboronic acid. The Suzuki carbonylation of aryl iodides at 80 degrees C under balloon pressure of carbon monoxide in the presence of K2CO3 as a base was examined, and good to high conversions and excellent selectivities were obtained.