Exploiting Deprotonative Co-complexation to Access Potassium Metal(ates) Supported by a Bulky Silyl(bis)amide Ligand
Exploiting Deprotonative Co-complexation to Access Potassium Metal(ates) Supported by a Bulky Silyl(bis)amide Ligand
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DOI：
10.1002/ejic.202001051
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发表时间：
2021-01-20
影响因子：
2.3
通讯作者：
Hevia, Eva
中科院分区：
文献类型：
--
作者：
Mastropierro, Pasquale;Kennedy, Alan R.;Hevia, Eva
将碱金属与较低正电性金属结合的双金属络合物已表现出独特的化学特征，可以在化学协同性方面合理化。为了推进这些类型配合物的合理设计，描述了一种适应性强的方法来制备新的钾金属盐家族，其中含有高空间要求的甲硅烷基（双）酰胺{Ph2Si(NAr*)(2)}(2-) (Ar*=2,6-二异丙基苯基)。使用顺序去质子共络合方法，使用烷基钾 KCH2SiMe3 完成 Ph2Si(NHAr*)(2) (1) 的单金属化，生成 [{Ph2Si(NHAr*)(NAr*)K}(无穷大)] (2)，而后者又与相关的 M(CH2SiMe3)(2) (M=Mg、Zn、Mn) 进行共络合，从而使剩余的金属化NHAr* 基团提供甲硅烷基双(酰胺基)烷基钾金属盐) [{Ph2Si(NAr*)(2)M(THF)(x)(CH2SiMe3)}(-){K(THF)(y)}(+)] (M=Zn, x=0, y=4, 3;M=Mg, x=1, y=3, 4;并且 M=Mn, x=0, y=4, 5）。锰酸钾 5 与胺 HMDS(H) (HMDS=N[SiMe3](2) 的反应性研究揭示了 Mn 上剩余烷基的动力学活化 [K(THF)(2){Ph2Si(NAr*)(2)}Mn(HMDS)] (6)。这些双金属配合物以及钾前体 2 的结构已通过 X 射线晶体学研究建立。
Bimetallic complexes combining an alkali-metal with a lower electropositive metal have demonstrated unique chemical profiles which can be rationalised in terms of chemical cooperativity. Advancing the rational design of these types of complexes, a adaptable method is described to prepare a new family of potassium metal(ates) containing the highly sterically demanding silyl(bis)amide {Ph2Si(NAr*)(2)}(2-) (Ar*=2,6-diisopropylphenyl). Using a sequential deprotonative co-complexation approach, mono-metallation of Ph2Si(NHAr*)(2) (1) is accomplished using potassium alkyl KCH2SiMe3 yielding [{Ph2Si(NHAr*)(NAr*)K}(infinity)] (2), which, in turn, undergoes co-complexation with the relevant M(CH2SiMe3)(2) (M=Mg, Zn, Mn) enabling metallation of the remaining NHAr* group to furnish silylbis(amido) alkyl potassium metal(ates) [{Ph2Si(NAr*)(2)M(THF)(x)(CH2SiMe3)}(-){K(THF)(y)}(+)] (M=Zn, x=0, y=4, 3; M=Mg, x=1, y=3, 4; and M=Mn, x=0, y=4, 5). Reactivity studies of potassium manganate 5 with the amine HMDS(H) (HMDS=N[SiMe3](2) revealed the kinetic activation of the remaining alkyl group on Mn furnishing [K(THF)(2){Ph2Si(NAr*)(2)}Mn(HMDS)] (6). The structures of these bimetallic complexes along with that of the potassium precursor 2 have been established by X-ray crystallographic studies.