Solvent-free, open-vessel microwave-promoted Heck couplings: From the mmol to the mol scale

The rapid, microwave-promoted Heck coupling of aryl iodides in open reaction vessels is presented and scale-up of the reactions to the mol scale demonstrated. Reactions are performed using 0.1 mol% palladium acetate as the catalyst, sodium carbonate and tributylamine as bases and tetrabutylanimonium bromide as an additive.