Tin–carbon bond formation by simple addition of cyclic dienes to a bis(amino)stannylene: a mechanistic study
摘要:
The addition of cyclopentadiene and indene to Bu'NSiMe(2)NBu'Sn resulted in the formation of 'adducts' (X-ray structural characterisation) through tin-carbon bonding and hydrogen migration to one of the nitrogen atoms. In the cyclopentadienyl compound pi bonding is observed (Sn-C 2.47-2.76 Angstrom) whereas the indenyl derivative displays a sigma-bond (Sn-C 2.343 Angstrom). In a similar reaction of Bu'NSiMe(2)NBu'E (E = Ge or Pb) with cyclopentadiene either the starting compounds or plumbocene along with an amine were isolated. At room temperature the reaction between indene and the cyclic stannylene is an equilibrium, the rate constants of which were raised by a factor of 3.0 for the association and slowed by a factor of 4.2 for the dissociation when deuteriated indene was used. From the kinetic data, a concerted addition mechanism of the proton and the indenyl group is favoured over an ionic two-step mechanism. If the steric hindrance of the protic cyclic diene system is raised (pentamethylcyclopentadiene) no reaction between the stannylene and diene is observed.
diffraction techniques. The two compounds form similar polycyclic, centrosymmetrical assemblies of metal atoms bridged by chlorine or nitrogen atoms. While in the case of the cobalt compound Co is pentacoordinated by three chlorine and two nitrogen atoms, in the zinc derivative Zn is almost tetrahedrally coordinated by three chlorine atoms and one nitrogen atom. The iron derivative [Me(2)Si(NtBu)(2)Sn.FeCl(2)](2)
Synthese und Charakterisierung der Siloxialane [H2AlOSiMe3]n und [HAl(OtBu)(OSiMe3)]2 sowie Redoxreaktionen von [H2AlOSiMe3]n und [H2AlOtBu]2 mit einem Zinn(II)-amid
[H2AIOtBu]2 (1) and [HA1(OtBu)2]2 (2) the siloxialane [H2A1In Anlehnung an die Darstellungen von [H2AlOtBu]2 (1) und [HAl(OtBu)2]2 (2) wurde das Siloxialan [H2AlOSiMe3]n (3) synthetisiert und erstmals rontgenographisch gesichert. In Losung liegt 3 tetramer (n = 4) und im Festkorper polymer (n = ∞) in Kettenform vor. Allerdings fuhrt die Umsetzung von Aluminiumhydrid mit der zweifachen molaren Menge an
[H2AIOtBu]2 (1) 和 [HA1(OtBu)2]2 (2) 合成后,硅氧烷 [H2A1In Anlehnung an die Darstellungen von [H2AlOtBu]2 (1) 和 [HAl(OtBu)2]2 (2) ) wurde das Siloxialan [H2AlOSiMe3]n (3) 合成器 rontgenographisch gesichert。在Kettenform vor 中的Losung liegt 3 四聚体(n = 4)和im Festkorper 聚合物(n = ∞)中。Allerdings fuhrt die Umsetzung von Aluminiumhydrid mit der zweifachen Molden Menge an Trimethylsilanol nicht zum erwarteten Monohydrid
Reactions of Germylenes and Stannylenes with Halo(hydrocarbyl)- and Chloro(amino)phosphines: Oxidative Addition versus Ligand Transfer
作者:Joseph K. West、Lothar Stahl
DOI:10.1021/acs.inorgchem.7b01275
日期:2017.11.6
faster than germylenes, and these reactions are first-order in both reactants and slowed by stericbulk. Kinetic data and the structures of intermediates and products had suggested an adduct/insertion mechanism for these reactions. To gain further insight into these transformations, the work presented herein was extended to chloro(hydrocarbyl)phosphines with varying organic substituents. These studies
氧化加成(OA)是化学中一个重要的基本步骤,但主要在过渡金属催化的反应环境中进行了研究,并且主要在碳X底物(X =卤素,H)中进行了研究。相比之下,主要的金属化合物经历OA的报道很少,而涉及磷-卤素底物的报道仍然很少。无环和环状的二氮杂亚甲基和-亚锡烷基在氧化加成产物的中间与氯(烃基)膦反应。亚苯乙烯的反应速度比亚甲基苯还快,并且这些反应在两种反应物中都是一阶反应,并且由于空间体积而减慢。动力学数据以及中间体和产物的结构表明了这些反应的加合物/插入机理。为了进一步了解这些转变,本文提出的工作扩展到具有不同有机取代基的氯(烃基)膦。这些研究证实了有关立体空间速率降低作用的先前结论,并且速率对离去基团的依赖性似乎也暗示加合物/插入或S N 2机制。重要的是,这些新数据现在也指向关联的分解途径。在研究过程中,发现脂肪族氯(氨基)膦与卡宾类似物的反应不同,从而为亚二甲苯生成了氧化加成产物,但为亚苯乙烯生成了易位反应。
Stickstoffverbindungen von elementen der dritten hauptgruppe mit intra- und intermolekularen donor-akzeptor-bindungen
作者:M. Veith、W. Frank、F. Töllner、H. Lange
DOI:10.1016/0022-328x(87)87003-1
日期:1987.6
distance of 261(1) pm. The most remarkable feature is a N(Mg,Al,Si)N trigonal bipyramid, which originates from intramolecular two-centre and donor-acceptor bonds (AlN 187.7(6) and 188.6(6) pm, SiN 180.6(5), and 181.0(6) pm). The three neighbouring elements of the periodic table Mg, Al, and Si are thus bonded to a common nitrogen atom, which has a t-butyl group as an additional ligand. Derivatives of X have
路易斯酸性元素Li,Na,Mg和Al已成功地掺入以Me 2 Si(N t Bu)2单元为常见分子片段的环状结构中。[Me 2 Si(N t Bu)2 Mg·THF] 2(II)和[Me 2 Si(N(t Bu)AlMe 2)(N(t Bu)MgI)] 2( X)显示该化合物为二聚体。在II的情况下,两个四元SiN 2 Mg循环通过NMg键相互作用,形成点对称为C i的第三个N 2 Mg 2循环()。镁原子通过四氢呋喃配位与四个不同的MgN键(199.3(4),211.2(4)和218.8(4)pm)配位和一个MgO键(204.9(6)pm)配位。 。在X中,二聚体由IMg相互作用产生,再次形成向心对称的Mg 2 I 2。长方形。镁原子进一步由两个氮原子配位,两个MgN键长分别为225.9(6)和229.9(6)pm,甲基位于261(1)pm处。最显着的特征是N(Mg,Al,Si)
Cyclische diazastannylene
作者:M. Veith、H. Lange、K. Bräuer、R. Bachmann
DOI:10.1016/s0022-328x(00)85818-0
日期:1981.8
Me2Si(N-t-Bu)2Sn (I) reacts under UV-irradiation with hexacarbonyl-chromium-molybdenum to mono-stannylene complexes Me2Si(N-t-BU)2SnM-(Co)5 (II, M = Cr; III, M = Mo) and in the case of molybdenum also to a bis-stannylene-complex [Me2Si(N-t-Bu)2Sn]2Mo(CO)4 (IV) presumably of cis structure. Alternatively I may also displace tetrahydrofuran in (THF)M(CO)5 to yield II and III.