Carbon-carbon bond formation catalyzed by PEPPSI Pd-NHC

Five new palladium complexes were efficiently synthesized from the reaction of benzimidazolium salts, potassium carbonate (K2CO3) and palladium chloride (PdCl2) in pyridine (for 3-5) or 3-chloropyridine (for 6 and 7). The synthesized complexes were characterized and tested in Suzuki-Miyaura cross-coupling reaction as catalysts. In the presence of catalysts 3-7, biaryl products were obtained in moderate yields when phenylboronic acid was used as boronic acid derivative. However, the coupling of thianaphthene-2-boronic acid with 1-chloro-4-nitrobenzene generated low yields although a longer period of time was used in comparison to the coupling of phenylboronic acid with aryl chlorides. (C) 2017 Elsevier B.V. All rights reserved.