Synthesis, structure, and catalytic activity of palladium(II) complexes of new CNC pincer-type N-heterocyclic carbene ligands

New CNC pincer-type N-heterocyclic carbene ligands with a central diarylamido moiety are presented. Palladium(II) pincer complexes of type [Pd(L)Cl] (L = bis[2-(3-alkylimidazolin-2-yliden-1-yl)-4-methylphenyl]amido) 5a-c (5a, alkyl = benzyl; 5b, alkyl = n-butyl; 5c, alkyl = 2,4,6-trimethylbenzyl) were obtained from the corresponding silver carbene complexes and [PdCl2(MeCN)(2)] without addition of external bases. The palladium pincer complex 5a was characterized by X-ray diffraction. The molecular structure of 5a shows a distorted square-planar coordination geometry for the palladium atom. Pincer complexes 5a-c have been shown to be active catalysts for the Suzuki-Miyaura reactions.