Controlled synthesis of nickel(ii) dihalides bearing two different or identical N-heterocyclic carbene ligands and the influence of carbene ligands on their structures and catalysis
作者:Zhi-hong Liu、Yan-Chao Xu、Ling-Zhi Xie、Hong-Mei Sun、Qi Shen、Yong Zhang
DOI:10.1039/c1dt10077g
日期:——
ol-2-ylidene), X = Cl, 1; X = Br, 2] and Ni(iPr)(IMes)Br2 [IMes = 1,3-bis(mesityl)imidazol-2-ylidene, 3]. Alternatively, complexes 1–3 can be synthesized using a bis-indenyl Ni(II) complex (1-H-Ind)2Ni as starting materials via a step-by-step indene elimination at different reaction temperatures. The direct reaction of (1-R-Ind)2Ni (R = H or Me) with two equiv. of imidazolium salts at 100 °C afforded
已经通过受控的茚消除合成法制备了带有两个不同或相同的NHC配体的Ni(II)二卤化物,并且前一种产品为双卡宾Ni(II)基催化剂的设计提供了一条新途径。这茚一当量的茚合镍(II)配合物(1-H-Ind)Ni(NHC)X(Ind =茚基)的消除反应。在100°C下制备独特的咪唑鎓盐,得到了带有两个不同NHC配体的Ni(II)二卤化物的第一个例子,即Ni(iPr)(IPr)X 2 [iPr = 1,3-二异丙基咪唑-2-亚烷基,IPr = 1,3-双(2,6-二异丙基苯基)咪唑-2-亚烷基),X = Cl,1;X = Br,2 ]和Ni(iPr)(IMes)Br 2 [IMes = 1,3-双(间苯二甲酰亚胺)咪唑-2-亚 基,3 ]。或者,可以使用双茚基镍(II)配合物(1-H-Ind)2 Ni作为起始原料合成配合物1-3通过在不同的反应温度下逐步消除茚。(1-R-Ind)2 Ni(R = H或Me)与两个当量的直接反应