Synthesis of new surfactant-like triazine-functionalized ligands for Pd-catalyzed Heck and Sonogashira reactions in water

In this study, a novel class of ligands for palladium-catalyzed C-C coupling reactions in water is introduced. A range of triazine-functionalized ligands were synthesized using 2,4,6-trichloro-1,3,5-triazine (TCT) reagent. Among them, N-2, N-4, N-6-tridodecyl-1,3,5-triazine-2,4,6-triamine (TDTAT) was found to be an efficient ligand for the Pd-catalyzed Heck and Sonogashira reactions in water, which acted as a green solvent. TEM analysis showed that in the presence of TDTAT in water at 80 degrees C, PdCl2 is converted to nanoparticles with an average size of similar to 3 nm. The formed Pd-nanoparticles act as efficient catalytic species for C-C bond formation reactions in neat water. Under these conditions, Pd-catalyzed Heck and Sonogashira reactions are accomplished without the need for phosphine ligand. The generation of emulsion droplets (5-10 mm) containing Pd(0) nanoparticles would function as an effective reactor to accelerate the rate of the reaction in water media.