Turkish Journal of Chemistry, Vol.39, No.6, 1171-1179, 2015
Palladium-catalysed Suzuki-Miyaura cross-coupling with imidazolylidene ligands substituted by crowded resorcinarenyl and calixarenyl units
Two N-heterocyclic carbene (NHC) palladium complexes of formula [PdBr2 (NHC)(pyridine)] in which the carbenic ring is flanked by sterically crowded cavitand substituents were prepared from appropriate imidazolium salts bearing either two resorcinarene or a combination of resorcinarene and calixarene fragments. Both complexes displayed high stability and good activities in the cross-coupling of aryl bromides with phenyl boronic acid. One of the imidazolium salts was characterised by an X-ray diffraction study.
Keywords:Resorcinarene;calixarene;cavitands;N-heterocyclic carbene;palladium;PEPPSI complexes;Suzuki-Miyaura coupling