Coordinatively Unsaturated Dinickel Complexes as Concerted Catalysts and Preparation of Usable Catalytic System

阐明了含N-杂环卡宾的一价镍(I)络合物催化卤代芳烃交叉偶联反应的详细协同机理，开发了通用的催化工艺。(1)首先分离和测定了镍(I)中间体，并记录了EXAFS和XANES光谱，确定了它们的结构。(1)机理分析表明，在催化反应过程中，Ni(I)-Ni(I)和Ni(II)-Ni(II)之间可能存在氧化还原循环。(2)即使在室温下，芳基卤化物与活性较低的联芳胺的Buchwald-Hartwig胺化反应也可以进行。(3)制备了稳定的和活性较强的镍(I)催化剂前驱体。

Clarification of detailed concerted mechanism in the catalytic cross-coupling reactions of aryl halides using monovalent dinickel(I) complex bearing N-heterocyclic carbene, and development of versatile catalytic process have been achieved. (1) First, dinickel(I) intermediary compounds were isolated and determined, and EXAFS and XANES spectra were recorded to determine the structure of them. (1) Mechanistic consideration revealed that a redox cycle between Ni(I)-Ni(I) and Ni(II)-Ni(II) is possible during the catalytic reactions. (2) Buchwald-Hartwig amination of aryl halides with less reactive biarylamines proceeds even at room temperature. (3) Stable and reactive catalyst precursors of nickel(I) are prepared.