Unsymmetrical Chiral PCN Pincer Palladium(II) and Nickel(II) Complexes with Aryl-Based Aminophosphine–Imidazoline Ligands: Synthesis via Aryl C–H Activation and Asymmetric Addition of Diarylphosphines to Enones
作者:Ming-Jun Yang、Yan-Jing Liu、Jun-Fang Gong、Mao-Ping Song
DOI:10.1021/om200350h
日期:2011.7.25
distorted-square-planar geometry. The potential of the obtained chiral pincers in the asymmetricaddition of diarylphosphines to β-substituted enones or trans-β-nitrostyrene was investigated. The Pd pincer 4c, the chirality of which originated from l-phenylglycinol, was found to be an effective catalyst for the asymmetricaddition of diphenylphosphine to a series of β-aryl enones with high enantioselectivities
通过将市售3-硝基苯甲酸中的羧基和硝基分别转化为手性咪唑啉和胺,可以轻松合成手性3-(2'-咪唑啉基)苯胺3a – c。的3-(2'-咪唑啉基)一锅磷酸/金属化反应的苯胺图3a - Ç,其中在氨基3A - Ç物首先通过与PPH反应磷酸化2氯,接着金属化用的PdCl 2或无水的NiCl 2原位提供了三种不对称的手性PCN钳形Pd(II)配合物4a – c和Ni(II)配合物5a与芳基氨基膦-咪唑啉配体通过相关配体的芳基C–H键活化作用。所有新化合物均通过元素分析(配体前体的HRMS),1 H和13 C NMR,31 P 1 H} NMR(用于钳形配合物)和IR光谱进行了表征。Pd络合物4a,c和Ni络合物5a的分子结构已经通过X射线单晶衍射确定。每个复合体均采用典型的扭曲正方形平面几何形状。研究了所获得的手性钳在将二芳基膦不对称加成到β-取代的烯酮或反式-β-硝基苯乙烯中的潜力。钯钳4c