Palladium(II) tetrakis(4-N,N,N-trimethylammoniumphenylene)porphyrin supported on ion-exchange resins as efficient and reusable catalysts for C-C coupling reactions

Abstract

In this research, the Heck and Suzuki reactions catalyzed by tetrakis(4-N,N,N-trimethylammoniumphenylene)porphyrinatopalladium(II) iodide, [Pd(TTMAPP)]I4, immobilized on ion-exchange resins such as Dowex 50 WX8 and Amberlite IR-120 are reported. In this manner, first, tetrakis(4-N,N-dimethylaminophenylene)porphyrin was converted to tetrakis(4-N,N,N-trimethylammoniumphenylene)porphyrin iodide, [H 2TTMAPP]I4, with methyl iodide. Then this water soluble porphyrin was metalated by palladium(II) chloride and the [Pd(TTMAPP)]I 4 was produced. This cationic palladium porphyrin was immobilized onto the ionic supports via electrostatic interactions. The catalysts, [Pd(TTMAPP)]@Dowex 50 WX8 and [Pd(TTMAPP)]@Amberlit IR-120, were characterized by FT-IR and diffuse reflectance UV-Vis spectroscopic methods, and scanning electron microscopy. These heterogeneous catalysts are thermally stable, oxygen insensitive, phosphine-free, air- and moisture-stable in the C-C coupling reactions and are reusable several times without significant loss of their catalytic activity. © 2014 Elsevier B.V. All rights reserved.