Past and Present Research Systems of Green Chemistry

Palladium catalyzed Suzuki and Heck coupling reactions are the most powerful synthetic method for forming biaryls. These cross-coupling reactions of aryl-halides with organoboron compounds are an essential tools of almost every synthetic chemist, being used in the synthesis of pharmaceuticals, ligands, natural products, polymers and speciality molecules. Recently cross-coupling reactions in aqueous media have sparked research interest. Water is an inexpensive, readily available, non-toxic and enviromentally friendly alternative solvent in organic synthesis but is especially important in facilitating catalyst-product seperation. According to our previous publications, multicore palladium complexes have some advantages over analogous

monocore complexes. Multicore complexes may have adidtional states, which give the complex extra stability. Interaction between nearby metal centers could potentially cause increased reaction yield or yield transformation rates which is not possible via monocore complexes. Distence between metal centers also plays an impotant role in catalytic performance. In this publication, we report a series of water soluble multicore palladium(II) diimine complexes as catalysts for Suzuki and Heck reactions in aqueous media and make comparision against their analogous monocore complexes.