Synthesis and characterization of new palladium(II) complex derived from new phosphonium ylide and investigation of its catalytic activity

The catalytic complex of palladium is one of the most powerful tools for creating a C-C bond in organic synthesis. As a result, various types of palladium complexes have been developed with different ligands [1]. Herein we used the phosphorus ylide as a ligand for synthesis Pd complex. This ylide is capable of forming stable complexes that can be identified by NMR spectroscopic and X-ray crystallographic methods. Also they can behave as ambidentate ligands, because the carbanion located at the Cα of the ylide or the enolate oxygen is able to donate electron density to a transition metal [2]. We studied on the catalytic properties of palladium(II) complex with the new phosphonium ylide in Sonogashira cross-coupling reaction. Results showed that ylide with an electron-donating structure, was most efficient and enabled the coupling of various aryl halide with aryl terminal alkyne in good to excellent yields. The ease of preparation of the ylidic ligand, its high solubility in organic solvents, very low catalyst loading and stability toward air and moisture make it an ideal catalytic system for cross-coupling reactions.