Synthesis of novel allyl palladium complexes bearing purine based NHC and a water soluble phosphine and their catalytic activity in the Suzuki-Miyaura coupling in water

We have synthesized and fully characterized some novel allyl palladium complexes stabilized by mixed spectator ligands, namely the water soluble sodium 3,3′,3″-phosphinetriyltribenzenesulfonate, (TPPTS) and three carbenes derived from differently alkylated natural xanthines. In order to explore their potential applications we have tested their catalytic activity in the Suzuki-Miyaura coupling of para-bromoacetophenone with phenyl boronic acid, chosen as standard reaction. Only one of the complexes under study displays a remarkable stability in water and catalytic activity. We have therefore undertaken a catalytic investigation. These results are reported in the present paper together with the solid state structural characterization of a silver precursor of the palladium allyl complexes.