Zhang Jin, Li Tao, Li Xue, Zhang Gaopeng, Fang Shuai, Yan Wenxuan, Li Xiangyang, Yang Xiufang, Ma Yangmin, Szostak Michal
College of Chemistry and Chemical Engineering, Key Laboratory of Chemical Additives for China National Light Industry, Shaanxi University of Science and Technology, Xi'an 710021, China.
Kaili Catalyst & New Materials CO., LTD, Xi'an 710299, China.
Chem Commun (Camb). 2022 Jun 30;58(53):7404-7407. doi: 10.1039/d2cc02253b.
We report the synthesis, characterization and reactivity of an air-stable, well-defined acenaphthoimidazolylidene palladium-BIAN-NHC chloro dimer complex, [Pd(BIAN-IPr)(μ-Cl)Cl]. This rapidly activating catalyst merges the reactive properties of palladium chloro dimers, [Pd(NHC)(μ-Cl)Cl], with the attractive structural features of the BIAN framework. [Pd(BIAN-IPr)(μ-Cl)Cl] is the most reactive Pd(II)-NHC precatalyst discovered to date undergoing fast activation under both an inert atmosphere and aerobic conditions. The catalyst features bulky-yet-flexible sterics that render the C-H substituents closer to the metal center in combination with rapid dissociation to monomers and strong σ-donor properties. [Pd(BIAN-IPr)(μ-Cl)Cl] should be considered as a catalyst for reactions using well-defined Pd(II)-NHCs.
我们报道了一种空气稳定、结构明确的苊并咪唑亚基钯-BIAN-NHC氯二聚体配合物[Pd(BIAN-IPr)(μ-Cl)Cl]的合成、表征及反应活性。这种快速活化的催化剂将钯氯二聚体[Pd(NHC)(μ-Cl)Cl]的反应特性与BIAN骨架引人注目的结构特征相结合。[Pd(BIAN-IPr)(μ-Cl)Cl]是迄今为止发现的反应活性最高的Pd(II)-NHC预催化剂，在惰性气氛和有氧条件下均能快速活化。该催化剂具有庞大而灵活的空间位阻，使C-H取代基更靠近金属中心，同时能快速解离为单体并具有较强的σ-给体性质。[Pd(BIAN-IPr)(μ-Cl)Cl]应被视为使用结构明确的Pd(II)-NHC进行反应的催化剂。
