Ullmann Homocoupling Catalysed by Gold Nanoparticles in Water and Ionic Liquid

The gold-catalysed Ullmann-type homocoupling of aryl halides is carried out with two different methodologies: (i) under micellar catalysis conditions in water and (ii) using a molten tetralkylammonium ionic liquid as the reaction medium. Glucose is used as a clean and renewable reductant. Morphology, size, and chemical composition of the gold nanoparticles were ascertained by X-ray photoelectron spectroscopy, transmission electron microscopy and dynamic light scattering analyses. A plausible reaction mechanism is proposed.