Alkali Metal-Stabilized 1,3,5-Triphenylbenzene Monoanions: Synthesis and Characterization of the Lithium, Sodium, and Potassium Complexes†
Alkali Metal-Stabilized 1,3,5-Triphenylbenzene Monoanions: Synthesis and Characterization of the Lithium, Sodium, and Potassium Complexes†
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碱金属稳定的 1,3,5-三苯基苯单阴离子：锂、钠和钾络合物的合成和表征†
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发表时间：
2010
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通讯作者：
M. Westerhausen
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作者：
Sven Krieck;H. Görls;M. Westerhausen
碱金属稳定的1，3，5-三苯基苯单阴离子可以从碱金属出发通过各种反应得到。在二甲醚(1，2-二甲氧基乙烷)中用碱金属还原格氏化合物[{(2，4，6-Ph_3-C_6H_2)Mg(Dme)B_r}_2(μ-O，O‘-dme)](3)，通过金属−金属交换得到溶剂分离离子[(DME)_3A]+[C_6H_2，4，6-Ph_3]C6H_3(A=Li，Na(4))。与此相反，1，3，5-三苯基苯的自由基单阴离子是通过格氏试剂[{2，4，6-Ph_3-C_6H_2}mg(THF)_2Br](2)与四氢呋喃中的碱金属(包括以乙醚裂解为主要反应步骤)的易位反应生成的。用锂还原2得到[(TMTA)4Li7Br4O]+[C6H3-2，4，6-Ph_3]−(6)(TMTA=1，3，5-三甲基-1，3，5-三氮杂环己烷)。然而，2与钠和钾反应生成了无卤离子对[(四氢呋喃)3Na(μ-η6-C6H3-2，4，6-Ph_3)](7)和[(四氢呋喃)
Alkali metal stabilized monoanions of 1,3,5-triphenylbenzene can be obtained by various reactions starting from the alkali metal. Reduction of the Grignard compound [{(2,4,6-Ph3-C6H2)Mg(dme)Br}2(μ-O,O′-dme)] (3) in DME (1,2-dimethoxyethane) with alkali metals yields solvent-separated ions [(dme)3A]+[C6H2-2,4,6-Ph3]− (A = Li, Na (4)) with a localized 2,4,6-triphenylphenyl carbanion via metal−metal exchange. Contrarily to this observation, radical monoanions of 1,3,5-triphenylbenzene are generated via transmetalation of the Grignard reagent [{2,4,6-Ph3-C6H2}Mg(thf)2Br] (2) with alkali metals in THF (including ether cleavage as the dominant reaction step). Reduction of 2 with lithium yields the solvent-separated ion pair [(tmta)4Li7Br4O]+[C6H3-2,4,6-Ph3]− (6) (tmta = 1,3,5-trimethyl-1,3,5-triazinane) with an oxygen-centered lithium cage as complex cation. However, reactions of 2 with sodium as well as potassium lead to formation of halogen-free contact ion pairs [(thf)3Na(μ-η6-C6H3-2,4,6-Ph3)] (7) and [(thf)...