Palladium-catalysed synthesis of aryl-alkyl ethers using alkoxysilanes as nucleophiles

Changing the activator from tetrabutyl ammonium fluoride (TBAF) to sodium hydroxide unexpectedly switches the catalytic pathway of the Hiyama coupling reaction of vinyl trialkoxysilanes with aryl bromides into a Pd catalysed C-O bond forming reaction; if the correct conditions are used, high yields of aryl-alkyl ethers are observed. In addition, coupling between readily available tetraalkoxysilanes and aryl bromides can also be realised with NaOH or TBAF activation. The reactions take place in only 20 minutes if microwave heating is employed.