Ni(I)–X Complexes Bearing a Bulky α-Diimine Ligand: Synthesis, Structure, and Superior Catalytic Performance in the Hydrogen Isotope Exchange in Pharmaceuticals
作者:Cayetana Zarate、Haifeng Yang、Máté J. Bezdek、David Hesk、Paul J. Chirik
DOI:10.1021/jacs.9b00939
日期:2019.3.27
Br, I) complex as a nickel(I) derivative supported by a redox-neutral α-diimine chelate. The dimeric nickel hydride, [(ipcADI)Ni(μ2-H)]2, was prepared and characterized by X-ray diffraction; however, magnetic measurements and 1H NMR spectroscopy support monomer formation at ambient temperature in THF solution. This nickel hydride was used as a precatalyst for the hydrogen isotopeexchange (HIE) of
由庞大的 α-二亚胺螯合物 N, N'-bis(1 R,2 R,3 R,5 S) 支持的一系列 Ni-X (X = Cl, Br, I, H) 配合物的合成和光谱表征)-(-)-isopinocampheyl-2,3-butanediimine (ipcADI) 进行了描述。二亚胺负载的三配位镍 (I)-X 配合物已被提议作为许多催化转化的关键中间体,例如 CC 和 C-杂原子交叉偶联以及 CH 官能化,但迄今为止在合成方面仍然难以捉摸。结构、光谱、电化学和计算研究的组合被用来建立每个单体 [(ipcADI)NiX] (X = Cl, Br, I) 络合物的电子结构,作为由氧化还原支持的镍 (I) 衍生物。中性α-二亚胺螯合物。制备了二聚氢化镍,[(ipcADI)Ni(μ2-H)]2,并通过 X 射线衍射表征;然而,磁性测量和 1 H NMR 光谱支持在环境温度下在 THF 溶液中形成单体。这种氢化镍用作芳烃和药物中
Improved Catalysts for the Palladium-Catalyzed Synthesis of Oxindoles by Amide α-Arylation. Rate Acceleration, Use of Aryl Chloride Substrates, and a New Carbene Ligand for Asymmetric Transformations
作者:Sunwoo Lee、John F. Hartwig
DOI:10.1021/jo005761z
日期:2001.5.1
alpha-aryloxindole derivatives. Surprisingly, catalysts containing tert-butylphosphine ligands, which have been most reactive for ketone arylations, were less active than those containing PCy(3). Use of new, optically active heterocyclic carbene ligands gave substantial enantioselectivity in formation of an alpha,alpha-disubstituted oxindole. In contrast, a variety of optically active phosphine ligands