Thorium- and Uranium-Mediated C-H Activation of a Silyl-Substituted Cyclobutadienyl Ligand.
Thorium- and Uranium-Mediated C-H Activation of a Silyl-Substituted Cyclobutadienyl Ligand.
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DOI：
10.1021/acs.inorgchem.2c03534
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发表时间：
2022-12-19
影响因子：
4.6
通讯作者：
Layfield, Richard A.
中科院分区：
文献类型：
--
作者：
Tsoureas, Nikolaos;Rajeshkumar, Thayalan;Townrow, Oliver P. E.;Maron, Laurent;Layfield, Richard A.
氟元素的环丁二烯基配合物是一类相对较新但知之甚少的夹心和半夹心有机金属化合物。我们现在描述镁试剂[（η 4-Cb ""）Mg（THF）3]（1）（其中Cb ""是四（三甲基甲硅烷基）环丁二烯基）向四氯化钍（IV）和四氯化铀（IV）的环丁二烯基转移反应。1与AnCl_4发生1：1化学计量反应，同时Cb ""完整转移，得到半夹心配合物[（η_4-Cb ""）AnCl（μ-Cl）_3Mg（THF）_3]（An = Th，2; An = U，3）.使用2：1的反应化学计量产生[Mg2Cl3（THF）6][（η 4-Cb ""）An（η 3-C4H（SiMe3）3-κ-（CH2SiMe2）（Cl）]（An = Th，[Mg2Cl3（THF）6][4]; An = U [Mg2Cl3（THF）6][5]），其中一个Cb ""配体经历了三甲基甲硅烷基的环化，导致An-C σ-键的形成，四元环的质子化，以及与锕系元素的η 3-烯丙基相互作用。复杂的溶液相动力学观察与多核核磁共振光谱两个三明治复合物。导致形成4和5的反应机理的计算分析表明，环丁二烯基配体在锕系中心经历C-H活化。在氯化钍（IV）或氯化铀（IV）中加入两当量的大体积三甲基硅烷基取代的环丁二烯配体镁盐，导致一个配体的完整转移和第二个配体上的锕系中心的甲基C-H键的活化，随后形成η 3-烯丙基环丁二烯相互作用。
Cyclobutadienyl complexes of the f-elements are a relatively new yet poorly understood class of sandwich and half-sandwich organometallic compounds. We now describe cyclobutadienyl transfer reactions of the magnesium reagent [(η4-Cb'''')Mg(THF)3] (1), where Cb'''' is tetrakis(trimethylsilyl)cyclobutadienyl, toward thorium(IV) and uranium(IV) tetrachlorides. The 1:1 stoichiometric reactions between 1 and AnCl4 proceed with intact transfer of Cb'''' to give the half-sandwich complexes [(η4-Cb'''')AnCl(μ-Cl)3Mg(THF)3] (An = Th, 2; An = U, 3). Using a 2:1 reaction stoichiometry produces [Mg2Cl3(THF)6][(η4-Cb'''')An(η3-C4H(SiMe3)3-κ-(CH2SiMe2)(Cl)] (An = Th, [Mg2Cl3(THF)6][4]; An = U [Mg2Cl3(THF)6][5]), in which one Cb'''' ligand has undergone cyclometalation of a trimethylsilyl group, resulting in the formation of an An–C σ-bond, protonation of the four-membered ring, and an η3-allylic interaction with the actinide. Complex solution-phase dynamics are observed with multinuclear nuclear magnetic resonance spectroscopy for both sandwich complexes. A computational analysis of the reaction mechanism leading to the formation of 4 and 5 indicates that the cyclobutadienyl ligands undergo C–H activation across the actinide center. Adding two equivalents of a bulky, trimethylsilyl-substituted cyclobutadienyl ligand as the magnesium salt to thorium(IV) or uranium(IV) chloride results in intact transfer of one ligand and activation of a methyl C−H bond across the actinide center on the second ligand, with subsequent formation of an η3-allylic cyclobutadienyl interaction.
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影响因子：
4
作者：
Day, Benjamin M.;Chilton, Nicholas F.;Layfield, Richard A.
通讯作者：
Layfield, Richard A.
影响因子：
16.6
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影响因子：
8.4
作者：
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影响因子：
2.8
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影响因子：
16.6
作者：
Guo, Fu-Sheng;Tsoureas, Nikolaos;Layfield, Richard A.
通讯作者：
Layfield, Richard A.