Csok Zsolt, Vechorkin Oleg, Harkins Seth B, Scopelliti Rosario, Hu Xile
Laboratory of Inorganic Synthesis and Catalysis, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-ISIC-LSCI, BCH 3305, Lausanne CH 1015, Switzerland.
J Am Chem Soc. 2008 Jul 2;130(26):8156-7. doi: 10.1021/ja8025938. Epub 2008 Jun 4.
A new pincer-type bis(amino)amine (NN2) ligand and its lithium and nickel complexes, including Ni(II) methyl, ethyl, and phenyl complexes, were synthesized. The Ni(II) alkyl complexes react cleanly with alkyl halides including chlorides to form C-C coupled products and Ni(II) halides. More interestingly, the Ni(II) alkyls undergo unprecedented reactions with CH2Cl2 and CHCl3 to cleave all the C-Cl bonds and replace them with C-C bonds. The reactions are highly selective and lead to the first efficient catalytic coupling of CH2Cl2 with alkyl Grignards. A conversion of 82% and a turnover number of 47 are achieved within minutes. Coupling of CD2Cl2 and 1,1-dichloro-3,3-dimethylbutane with nBuMgCl is also realized. Preliminary mechanistic study suggests a radical initiated process for these reactions.
合成了一种新型钳型双（氨基）胺（NN2）配体及其锂和镍配合物，包括Ni（II）甲基、乙基和苯基配合物。Ni（II）烷基配合物能与包括氯化物在内的卤代烃发生干净的反应，形成碳-碳偶联产物和Ni（II）卤化物。更有趣的是，Ni（II）烷基与CH2Cl2和CHCl3发生前所未有的反应，断裂所有的C-Cl键并用C-C键取代它们。这些反应具有高度选择性，实现了CH2Cl2与烷基格氏试剂的首次高效催化偶联。几分钟内转化率达到82%，周转数达到47。还实现了CD2Cl2和1,1-二氯-3,3-二甲基丁烷与正丁基氯化镁的偶联。初步机理研究表明这些反应是自由基引发的过程。
