Molecular Library Obtained by Allene Insertion into the Pd−C Bond of Cyclopalladated Complexes: Biological and Pharmacological Evaluation

A minilibrary of cationic N-heterocycles has been prepared and evaluated. The potential for the preparation was a result of the high versatility of palladium-mediated chemistry. The synthesis of the novel molecules was based on intramolecular quaternization of tertiary amine attached allylpalladium. complexes. The steric and electronic factors of the reaction are discussed. The structures of the synthesized molecules made them candidates for precise biological and pharmacological evaluations. Of the various N-heterocyclic compounds, 2,2-dimethyl-3-methylenenaphtho[def]quinolizinium showed antibacterial activity at micromolar concentrations. This compound also proved to be a nanomolar competitive antagonist for the channel site of the nicotinic acetylcholine receptor. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).