Miyaura-Suzuki Cross Coupling Reactions: The Role of Pd/CaCO3 as Catalyst Reservoir

Miyaura-Suzuki reaction was carried out in water-ethanol solutions by using Pd/CaCO3 as catalyst. Very good yields were obtained using different bases, phosphates or carbonates. The catalyst was recycled up to seven times without any loss of activity. To evidence the presence of Pd(II) in solution as the true catalyst, the solids were removed by decantation and the reaction products were extracted with hexane. The waterethanol solution was recycled and kept catalytic activity.