The incorporation of saturated N-heterocyclic carbenes into palladium pre-catalysts gives high catalyst activity in the Suzuki coupling of aryl iodides, bromides and deactivated aryl chloride substrates, whereas the yield of the palladium catalyzed Heck reaction of deactivated aryl chlorides is negligible. The complexes were generated in the presence of Pd(OAc)(2) by in situ deprotonation of 1,3-dialkylimidazolinium salts LHX (1) which were characterized by conventional spectroscopic methods and elemental analyses. (C) 2003 Elsevier B.V. All rights reserved.
C1 Ege Univ, Dept Chem, TR-35100 Bornova, Turkey.
Inonu Univ, Dept Chem, TR-44069 Malatya, Turkey.