Approaching a "Naked" Boryl Anion: Amide Metathesis as a Route to Calcium, Strontium, and Potassium Boryl Complexes
Approaching a "Naked" Boryl Anion: Amide Metathesis as a Route to Calcium, Strontium, and Potassium Boryl Complexes
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接近“裸”硼基阴离子：酰胺复分解作为钙、锶和钾硼基络合物的途径
DOI：
10.1002/ange.202011839
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发表时间：
2020
影响因子：
--
通讯作者：
Protchenko A
中科院分区：
文献类型：
--
作者：
Protchenko A
用酰胺歧化反应合成了第一个结构表征的钙锶硼配合物：{(Me3Si)2N}M{B(NDippCH)2}(THF)n(M=Ca，n=2；M=Sr，n=3)，通过相应的双(酰胺)M{N(SiMe3)2}2(THF)2与(THF)2Li-{B(NDippCH)2}反应，合成了第一个结构表征的钙锶硼配合物。最值得注意的是，这种方法也可以应用于类似的钾酰胺K{N(SiMe3)2}，导致形成无溶剂的硼基钾二聚体[K{B(NDippCH)2}]2，它在室温下长时间(48 h)在固态中稳定。在结晶学上确定了K+离子与侧翼DIPP基团的异碳原子和重氮硼杂环的硼中心弱相互作用的二聚体结构，K⋅⋅⋅B距离为>；3.1 ？这些结构特征，再加上分子中原子(QTAIM)的计算表明，含硼片段接近于在凝聚相中作为“自由”硼阴离子的极限描述。
Amide metathesis has been used to generate the first structurally characterized boryl complexes of calcium and strontium, {(Me3Si)2N}M{B(NDippCH)2}(thf)n(M=Ca,n=2; M=Sr,n=3), through the reactions of the corresponding bis(amides), M{N(SiMe3)2}2(thf)2, with (thf)2Li‐ {B(NDippCH)2}. Most notably, this approach can also be applied to the analogous potassium amide K{N(SiMe3)2}, leading to the formation of the solvent‐free borylpotassium dimer [K{B(NDippCH)2}]2, which is stable in the solid state at room temperature for extended periods (48 h). A dimeric structure has been determined crystallographically in which the K+cations interact weakly with both the ipso‐carbons of the flanking Dipp groups and the boron centres of the diazaborolyl heterocycles, with K⋅⋅⋅B distances of >3.1 Å. These structural features, together with atoms in molecules (QTAIM) calculations imply that the boron‐containing fragment closely approaches a limiting description as a “free” boryl anion in the condensed phase.