Synthesis, characterization and catalytic properties of an N-heterocyclic carbene palladium-based complex

A palladium(II) complex, bis[1,3-bis-(2,4,6-trimethylbenzyl)benzimidazol-2-ylidene]palladium(II) chloride, Pd(NHC), bearing N-heterocyclic carbenes has been synthesized and characterized by elemental analysis, IR spectroscopy and 1H and 13C NMR spectroscopy. Crystal structure details of Pd(NHC) are also presented. The palladium centre in the complex lies on a crystallographic inversion centre and occupies a square-planar environment, with both chloride and N-heterocyclic carbene ligands adopting a trans arrangement with Cl–Pd–Cl and C–Pd–C angles are precisely 180°. The palladium–carbene complex was tested as a catalyst in the Suzuki–Miyaura cross-coupling reaction.

Graphical abstractA novel palladium(II) complex bearing N-heterocyclic carbenes have been synthesized by the reaction of Ag–NHC complex with the PdCl2(PhCN)2 into dichloromethane and characterized by elemental analyses, infrared, 1H and 13C NMR spectroscopy and single-crystal X-ray diffraction analysis. The catalytic studies on palladium(II) complex indicate that it is a potent catalyst for the Suzuki–Miyaura reaction of aryl chlorides with phenylboronic acid under air atmosphere.Figure optionsDownload full-size imageDownload as PowerPoint slide