Monodentate Palladium Complexes Bearing Abnormal and Normal Carbene Ligands with a Formally Identical Steric Environment
作者:Chun-Hung Ke、Bing-Chiuan Kuo、Debkumar Nandi、Hon Man Lee
DOI:10.1021/om4004219
日期:2013.9.9
environment around the metal center. The corresponding ligand precursors were prepared via the key steps based on Pd-catalyzed direct C–H arylation between imidazo[1,2-a]pyridine and aryl bromides and Cu-catalyzed C–N coupling reactions between benzoimidazole and aryl bromides. The new complexes were characterized by 1D and 2D NMR spectroscopy, X-ray crystallography, and elemental analysis. The isomeric
我们报告了一系列具有单齿异常和正常卡宾配体的新型异构Pd(II)配合物,在金属中心周围具有形式上完全相同的空间环境。相应的配体前体是通过基于咪唑并[1,2- a]之间的Pd催化的直接CH芳基化的关键步骤制备的]吡啶和芳基溴化物以及铜催化的苯并咪唑与芳基溴化物之间的C–N偶联反应。通过1D和2D NMR光谱,X射线晶体学和元素分析对新配合物进行了表征。配体的同分异构体对在其空间性质之间显示出较小的差异,这可以通过计算其掩埋体积来检查。发现异常卡宾Pd(II)配合物在催化Mizoroki–Heck偶联,直接C–H芳基化和脱羧偶联反应方面更有效,这显然可以归因于异常卡宾配体的更强的电子捐赠作用。