Palladium catalyzed Suzuki cross-coupling reactions using N,O-bidentate ligands

Palladium-catalyzed Suzuki cross-coupling reactions employing Schiff-bases as ligands toward a series of substituted arylbromides and boronic acids were pursued. In the presence of a N,O-bidentate ligand, 2-[1-(2,4,6-trimethyl-phenylimino)-ethyl] -phenol 5, the catalytic reactions could be carried out efficiently at room temperature with a wide array of arylbromides, even with electronically deactivated arenes. A deprotonated 5, 5', chelated palladium acetate complex, [5'Pd(II)(OAc)(solv)] 8, was proposed as a precursor of a genuine catalytically active species. (c) 2005 Elsevier Ltd. All rights reserved.