Unexpected CNN-to-CC Ligand Rearrangement in Pincer–Ruthenium Precatalysts Leads to a Base-Free Catalyst for Ester Hydrogenation
作者:Linh Le、Jiachen Liu、Tianyi He、Jack C. Malek、Tia N. Cervarich、John C. Buttner、John Pham、Jason M. Keith、Anthony R. Chianese
DOI:10.1021/acs.organomet.9b00373
日期:2019.9.9
esters, without the need for added base. The ligand structure–activity relationship in the series of CC-chelated complexes mirrors that in the precursor CNN-Ru complexes, potentially indicating a common catalytic mechanism. Density functional theory calculations establish a plausible mechanism for the CNN-to-CC rearrangement and demonstrate that this rearrangement is potentially reversible under the conditions
我们报告了一系列CNN-钳子-钌络合物Ru(CNN)HCl(CO)与叔丁醇钠和单齿钠反应转化为CC螯合形式的Ru(CC)(PR 3)2 H(CO)。膦。当膦是三苯基膦时,在室温下形成顺式膦配合物,其在升高的温度下转化为反式异构体。当膦是三环己基膦时,只有反式观察到-膦异构体。CC螯合的络合物是酯加氢的活性催化剂,无需添加碱。CC螯合配合物系列中的配体结构与活性之间的关系反映了前体CNN-Ru配合物中的配体结构与活性之间的关系,这潜在地表明了一种共同的催化机理。密度泛函理论计算建立了CNN到CC重排的合理机制,并证明了这种重排在酯加氢催化条件下是可逆的。