1,3-Dimesityl-4,5-dimethyl-1H-imidazol-3-ium Chloride丨CAS 1118916-80-5

1,3-Dimesityl-4,5-dimethyl-1H-imidazol-3-ium chloride is widely used as a precursor for generating N-heterocyclic carbenes (NHCs), particularly those that offer a balanced combination of steric bulk and strong σ-donating ability. Upon deprotonation, it forms a stable carbene that readily coordinates to metals such as Pd, Au, Ag, Ru, Ir, and Cu, producing efficient catalysts for cross-coupling reactions, hydrosilylation, allylation, olefin metathesis, and various C–C and C–X bond-forming processes. Its mesityl substituents and additional methyl groups on the imidazole ring increase steric hindrance and electron density, making the derived NHC an effective ligand for homogeneous catalysis in pharmaceutical synthesis, polymer chemistry, fine-chemical production, and materials-oriented transformations. The compound is also used in catalytic method development, mechanistic studies of NHC–metal interactions, and research programs focused on designing high-performance, air-stable, and thermally robust catalytic systems.

The primary benefits of this compound stem from its steric and electronic properties, which are optimized for generating stable and reactive NHC ligands. The bulky mesityl groups protect metal centers from deactivation pathways, improving catalyst durability and resistance to aggregation or decomposition. The electron-rich carbene produced from this salt enhances metal-ligand bonding strength, often resulting in higher turnover numbers, better yields, and improved selectivity in complex reactions. The additional methyl groups on the ring fine-tune the electronic environment, enabling more precise control over catalytic behavior. The chloride counterion ensures good solubility and predictable reactivity during carbene generation, supporting consistent performance in laboratory and industrial settings. Overall, the material provides a dependable route to high-efficiency metal catalysts suitable for demanding synthetic applications.