Gold-Mediated Insertion of Oxygen into Silicon–Silicon Bond: An Original Au(I)/Au(III) Redox Sequence

Triangular Palladium Cluster from Activation of the Si-Si Bond in a Disilane with Phosphine Pendants

A disilane that contains two diphenylphosphino moieties, (Ph₂PCH₂)Ph₂Si-SiPh₂(CH₂PPh), was readily synthesized from the reaction of ClPh₂Si-SiPh₂Cl with (tmeda)Li(CH₂PPh₂). Treatment of the thus-obtained disilane with the palladium(0) precursor [Pd(CN^tBu)₂]₃ led to the exclusive formation of a trinuclear palladium cluster in which three palladium atoms are arranged in a triangular fashion. Single-crystal X-ray diffraction analysis of the obtained triangular cluster revealed that novel silylphosphido chelating ligands were formed via a skeletal rearrangement of the ligand framework.

Gold-Catalyzed Cross-Coupling Reactions: An Overview of Design Strategies, Mechanistic Studies, and Applications

Transition-metal-catalyzed cross-coupling reactions are central to many organic synthesis methodologies. Traditionally, Pd, Ni, Cu, and Fe catalysts are used to promote these reactions. Recently, many studies have showed that both homogeneous and heterogeneous Au catalysts can be used for activating selective cross-coupling reactions. Here, an overview of the past studies, current trends, and future directions in the field of gold-catalyzed coupling reactions is presented. Design strategies to accomplish selective homocoupling and cross-coupling reactions under both homogeneous and heterogeneous conditions, computational and experimental mechanistic studies, and their applications in diverse fields are critically reviewed. Specific topics covered are: oxidant-assisted and oxidant-free reactions; strain-assisted reactions; dual Au and photoredox catalysis; bimetallic synergistic reactions; mechanisms of reductive elimination processes; enzyme-mimicking Au chemistry; cluster and surface reactions; and plasmonic catalysis. In the relevant sections, theoretical and computational studies of Au^I /Au^III chemistry are discussed and the predictions from the calculations are compared with the experimental observations to derive useful design strategies.

Oxidant-free oxidative gold catalysis: the new paradigm in cross-coupling reactions

The construction of C–C and C–X (X = hetero atom) bonds is the core aspect for the assembly of molecules. This feature article critically presents an overview of all the redox neutral cross-coupling reactions enabled by gold catalysis, which we believe would stimulate further research activities in this promising area.

Disiloxane Synthesis Based on Silicon-Hydrogen Bond Activation using Gold and Platinum on Carbon in Water or Heavy Water

Disiloxanes possessing a silicon-oxygen linkage are important as frameworks for functional materials and coupling partners for Hiyama-type cross coupling. We found that disiloxanes were effectively constructed of hydrosilanes catalyzed by gold on carbon in water as the solvent and oxidant in association with the emission of hydrogen gas at room temperature. The present oxidation could proceed via various reaction pathways, such as the hydration of hydrosilane into silanol, dehydrogenative coupling of hydrosilane into disilane, and the subsequent corresponding reactions to disiloxane. Additionally, the platinum on carbon catalyzed hydrogen-deuterium exchange reaction of arylhydrosilanes as substrates in heavy water proceeded on the aromatic nuclei at 80 °C with high deuterium efficiency and high regioselectivity at the only meta and para positions of the aromatic-silicon bond to give the deuterium-labeled disiloxanes.