Turkish Journal of Chemistry, Vol.38, No.4, 547-552, 2014
Application of 3-aroyl-4(5)-arylimidazols as efficient ligands in Pd-catalyzed Heck reactions
The Heck coupling of haloarenes with various alkenes was successfully performed in the presence of 0.25 mol% PdCl2 and 0.5 mol% biphenyl-4-yl-[4(5)-(biphenyl-4-yl)-1H -imidazol-2-yl]ketone 2f as a ligand with Na2CO3 as optimal base, in a 1:1 mixture of H2O/DMF as the reaction solvent at 80 degrees C for 8 h. Imidazole 2f was found to be an inexpensive, air-stable, easily available, and efficient ligand in the palladium-catalyzed Heck reactions of aryl iodides (76%-94%), bromides (52%-79%), and chlorides (40%-70%).