作者:Megan Mohadjer Beromi、Gourab Banerjee、Gary W. Brudvig、Nilay Hazari、Brandon Q. Mercado
DOI:10.1021/acscatal.8b00546
日期:2018.3.2
Ni(I) aryl species that are directly relevant to cross-coupling have been synthesized. Transmetalation of (dppf)NiIX (dppf = 1,1′-bis(diphenylphosphino)-ferrocene, X = Cl, Br) with aryl Grignard reagents or aryl boronic acids in the presence of base produces Ni(I) aryl species of the form (dppf)NiI(Ar) (Ar = Ph, o-tolyl, 2,6-xylyl, 2,4,6-mesityl, 2,4,6-iPr3C6H2). The stability of the Ni(I) aryl species
在这项工作中,已经合成了与交叉偶联直接相关的Ni(I)芳基物质。(dppf)Ni I X(dppf = 1,1'-双(二苯基膦基)-二茂铁,X = Cl,Br)在碱的存在下用芳基格氏试剂或芳基硼酸进行金属转移生成Ni(I)芳基形式(dppf)Ni I(Ar)(Ar = Ph,o -tolyl,2,6-xylyl,2,4,6-mesityl,2,4,6- i Pr 3 C 6 H 2)。Ni(I)芳基物种的稳定性与芳基配体上的空间体积成反比。最不稳定的Ni(I)芳基物质是Suzuki-Miyaura反应中最活跃的预催化剂,因为它们会迅速分解生成活性Ni(0)催化剂。这项研究表明,Ni(I)芳基物种最初是在Suzuki-Miyaura反应的卤化Ni(I)前置催化剂的活化过程中形成的,并建立了它们的化学计量和催化反应性特征。