Kaufmann Sebastian, Krätschmer Frederic, Köppe Ralf, Schon Thorben, Schoo Christoph, Roesky Peter W
Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT) Engesserstrasse 15 76131 Karlsruhe Germany
Chem Sci. 2020 Oct 26;11(46):12446-12452. doi: 10.1039/d0sc04174b.
The synthesis of a 1,2,3,4-tetramethylcyclopentadienyl (Cp) substituted four-membered N-heterocyclic silylene [{PhC(NBu)}Si(CMeH)] is reported first. Then, selected reactions with transition metal and a calcium precursor are shown. The proton of the Cp-unit is labile. This results in two different reaction pathways: (1) deprotonation and (2) rearrangement reactions. Deprotonation was achieved by the reaction of [{PhC(NBu)}Si(CMeH)] with suitable zinc precursors. Rearrangement to [{PhC(NBu)}(CMe)SiH], featuring a formally tetravalent silicon RC[double bond, length as m-dash]Si(R')-H unit, was observed when the proton of the Cp ring was shifted from the Cp-ring to the silylene in the presence of a Lewis acid. This allows for the coordination of the Cp-ring to a calcium compound. Furthermore, upon reaction with transition metal dimers [MCl(cod)] (M = Rh, Ir; cod = 1,5-cyclooctadiene) the proton stays at the Cp-ring and the silylene reacts as a sigma donor, which breaks the dimeric structure of the precursors.
首次报道了1,2,3,4-四甲基环戊二烯基（Cp）取代的四元氮杂硅烯[{PhC(NBu)}Si(CMeH)]的合成。然后，展示了其与过渡金属和钙前体的特定反应。Cp单元的质子不稳定。这导致了两种不同的反应途径：（1）去质子化和（2）重排反应。通过[{PhC(NBu)}Si(CMeH)]与合适的锌前体反应实现去质子化。当Cp环的质子在路易斯酸存在下从Cp环转移到硅烯时，观察到重排为[{PhC(NBu)}(CMe)SiH]，其具有形式上的四价硅RC[双键，长度为m破折号]Si(R')-H单元。这使得Cp环能够与钙化合物配位。此外，与过渡金属二聚体[MCl(cod)]（M = Rh，Ir；cod = 1,5-环辛二烯）反应时，质子保留在Cp环上，硅烯作为σ供体反应，这打破了前体的二聚结构。
