Highly Active, Well-Defined (Cyclopentadiene)(N-heterocyclic carbene)palladium Chloride Complexes for Room-Temperature Suzuki-Miyaura and Buchwald-Hartwig Cross-Coupling Reactions of Aryl Chlorides and Deboronation Homocoupling of Arylboronic Acids

A new class of well-defined N-heteroeyclic carbene (NHC)-(cyclopentadiene)palladium chloride complexes such as CpPd(NHC)Cl wasw synthesized from the readily available starting NHIC-palladium(11) chloride dimers. These air-stable, coordinatively saturated NHC-Pd complexes bearing the cyclopentadiene (Cp) unit exhibit high catalytic activity in the room temperature Suzuki-Miyaura and Buchwald-Hartwig cross-coupling reactions involving unactive aryl chlorides as the substrates. In addition, they are found to be extremely efficient catalysts in the deboronation homocoupling of arylboronic acids at room temperature.