2-hydroxyethyl-substituted (NHC)PdI2(pyridine) (Pd-PEPPSI) Complexes: Synthesis, Characterization and the Catalytic Activity in the Sonogashira Cross-coupling Reaction

Here, new series of the 2-hydroxyethyl-substituted (NHC)PdI2(pyridine) (Pd-PEPPSI) complexes have been synthesized. These complexes have been prepared from the 2-hydroxyethyl-substituted N-heterocyclic carbene (NHC) precursors, palladium chloride and pyridine. The synthesized Pd-PEPPSI complexes have been characterized by using H-1 NMR, C-13 NMR, FTIR spectroscopy and elemental analysis techniques. The catalytic activity of the 2-hydroxyethyl-substituted Pd-PEPPSI complexes has been examined in the Sonogashira cross-coupling reaction by using phenylacetylene and aryl bromide. The Pd-PEPPSI complexes have demonstrated great activity in the Sonogashira cross-coupling reaction. The molecular and crystal structures of the three of the Pd-PEPPSI complexes were determined by single-crystal X-ray diffraction method. X-ray studies show that all the molecular structures adopt slightly distorted square-planar geometry around the palladium (II) center