NHC Nickel Catalyzed Hiyama‐ and Negishi‐Type Cross‐Coupling of Aryl Fluorides and Investigations on the Stability of Nickel(II) Fluoroaryl Alkyl Complexes
作者:Maximilian W. Kuntze‐Fechner、Christoph Kerpen、David Schmidt、Mathias Häring、Udo Radius
DOI:10.1002/ejic.201801477
日期:2019.4.9
transfer from PhSi(OR)3 to the perfluoroarene occurs to yield ArF–OR and PhSiF(OR)2. Negishi cross‐coupling between C6F6 or C7F8 (1 equiv.), diorganozinc reagents [ZnR2] (R = Me, Et) (2.1 equiv.) and 5 mol‐% 1 as the catalyst in toluene at 115 °C leads to ArF–R only in traces. However, NMR experiments revealed that nickel alkyl complexes are readily formed from the reaction of trans‐[Ni(iPr2Im)2(F)(ArF)]
[Ni(i Pr 2 Im)4(µ-COD)] 1(i Pr 2 Im = 1,3-二异丙基-咪唑啉-2-亚烷基,COD = 1,4-环辛二烯)的反应性报道了类型交叉偶联反应以及几种新型镍氟芳基烷基镍配合物的合成。相当于1.1的Hiyama联轴器。全氟芳烃和1当量 以5 mol%的1作为催化剂的PhSi(OR)3(R = Me,Et)导致C–C耦合产物Ar F –Ph的收率良好。在添加剂NMe 4 F的存在下,发生从PhSi(OR)3到全氟芳烃的烷氧基转移,生成Ar F-OR和PhSiF(OR)2。Negishi在C 6 F 6或C 7 F 8(1当量),二有机锌试剂[ZnR 2 ](R = Me,Et)(2.1当量)和5 mol%1作为甲苯中的催化剂之间的交叉偶联115°C仅导致痕量的Ar F –R。但是,NMR实验表明,反式-[Ni(i Pr 2 Im)2(F)(Ar F)]与[ZnR