Caged Iridium Catalyst for Hydrosilylation of Alkynes with High Site Selectivity

Abstract

The proximity and orientation of the reacting groups can be different in organic cages from in free solution, thus affecting the selectivity of the reaction. Herein, we reported a synthetic strategy to encapsulate iridium nanoparticles

Nano Si‐Doped Ruthenium Oxide Particles from Caged Precursors for High‐Performance Acidic Oxygen Evolution

“…Recently we developed a facile synthesis of an organic cage (COP1-T) with the diameters of several nanometers, [36] and subsequently show effectiveness of trapping various metal ions through coordinating carboxylate groups on its surface. [37,38] It was also demonstrated that unique selectivity could be obtained using these assemblies as catalysts for several kinds of reaction. Considering the suitability as carbon source for COP1-T with 72 phenyl rings per cage, we decided to evaluate the possibility of preorganizing ruthenium ions within a cage followed by calcination for a stable carbon-coated ruthenium OER catalyst.…”

The marriage of porous cages and metal clusters for advanced catalysis

“…In terms of hydrosilylation of terminal alkynes, the soluble nanosized Ir@COP1-T (average size: 1.5 nm) fabricated by Liu and co-workers displayed enhanced catalytic activity and selectivity ([ E ]/[ Z ] > 99%) for the formation of unusual β-( E ) products compared with the insoluble counterparts ([ E ]/[ Z ] = 70%). 35 In the blocking experiments, they further verified the encapsulation of Ir clusters inside the cage, as placing bulky ions around the cage window led to a complete loss of activity due to the blocked contact between the substrate and metal center.…”

“…7(b)). 35 In addition, other experimental analysis such as N 2 adsorption, can also offer auxiliary evidence to infer the spatial location of MCs based on the change in pore volume and surface area of cage supports before and after loading MCs (Fig. 7(c)).…”

Trialkoxysilane-Induced Iridium-Catalyzed para-Selective C–H Bond Borylation of Arenes

“…It is worth mentioning that the catalytic system does not require strict anhydrous and anaerobic conditions. Although the specific reasons are unclear, we may speculate that B 2 dmg 2 may form a cage-like structure with large steric hindrance with [Ir(cod)OMe] 2 and Me 4 phen to protect the iridium catalytic center, thereby act as a barrier between water and oxygen molecules in air and solvent 30 , 42 , 43 . In addition, the high reactivity of B 2 dmg 2 greatly increases the reaction rate, leading to the reactions to be completed quickly.…”