Structural changes accompanying the stepwise population of a B-C π bond
Structural changes accompanying the stepwise population of a B-C π bond
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DOI：
10.1002/anie.200702299
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发表时间：
2007-01-01
影响因子：
16.6
通讯作者：
Gabbaie, Francois P.
中科院分区：
文献类型：
--
作者：
Chiu, Ching-Wen;Gabbaie, Francois P.
由于它们的负电荷和大半径的硼，硼杂烯烃（类型A）通常是非常活泼的，只有在少数情况下被分离出来。[1-3]衍生物[Mes 2B = CH 2] n2（Mes= 2，4，6-三甲基苯基）是最简单的例子之一，并且通过相应的甲基化合物的去质子化分离。[1，4-6]虽然硼杂烯烃的化学尚未被广泛研究，但研究表明它们可以作为亲核试剂[4-6]或作为过渡金属络合物中的配体。[7-9]电生成的二硼杂烯烃，如[p-（Mes 2B）C6 H4（BMes 2）] 2 H4，也已使用光谱电化学检测。[10-12]然而，有趣的是，伴随着硼-碳π键的逐步布居/去布居的结构变化还没有实验研究。文献检查表明，这样的结构数据可用于四芳基二硼烷（B型），如Mes 2BBMesPh，其经历两次单电子还原，得到相应的自由基阴离子（BC 2型）和二价阴离子（B2型）。[13-16]对[Mes 2BBMesPh] C3和[Mes 2BBMesPh] 2C 4进行的结构研究证实，中性的还原
Owing to their negative charge and the large radius of boron, borataalkenes (type AÀ) are usually very reactive and have only been isolated on a few occasions.[1–3] The derivative [Mes2B= CH2] À (Mes= 2, 4, 6-trimethylphenyl) is one of the simplest examples, and was isolated by deprotonation of the corresponding methyl compound.[1, 4–6] While the chemistry of borataalkenes has not been widely investigated, studies have shown that they can act as nucleophilic reagents [4–6] or as ligands in transition-metal complexes.[7–9] Electrogenerated diborataalkenes, such as [p-(Mes2B) C6H4 (BMes2)] 2À, have also been detected using spectroelectrochemistry.[10–12] Interestingly, however, the structural changes accompanying the stepwise population/depopulation of a boron–carbon π bond have not been studied experimentally.Examination of the literature indicates that such structural data is available for tetraaryldiboranes (type B) such as Mes2BBMesPh which undergoes two one-electron reductions to afford the corresponding radical anion (type BCÀ) and dianion (type B2À).[13–16] Structural studies carried out on [Mes2BBMesPh] CÀ and [Mes2BBMesPh] 2À confirm that reduction of the neutral