β‐disilyl‐substitutedvinylcations were prepared by intramolecular addition of transient silylium ions to CC triple bonds. The vinylcations were isolated from hydrocarbon solutions as tetrakis(pentafluorophenyl) borates at room temperature. The substituents directly attached to the positively charged carbon atom were varied from tert‐butyl‐ to trialkylsilyl‐ to trialkylgermyl groups. The cations were
通过将瞬时甲硅烷离子分子内加成到 CC 三键上,制备了一系列 β,β-二甲硅烷基取代的乙烯基阳离子。乙烯基阳离子在室温下以四(五氟苯基)硼酸盐的形式从烃溶液中分离出来。直接连接到带正电荷的碳原子上的取代基从叔丁基到三烷基甲硅烷基到三烷基锗基不等。阳离子通过其特征13 C 和29 Si NMR 数据进行鉴定。NMR 研究揭示了 β,β-二甲硅烷基-α-锗基和三甲硅烷基取代的乙烯基阳离子具有高度动态的结构,其中两个乙烯基碳原子在室温下在 NMR 时间尺度上进行快速的分子内交换过程。核磁共振研究使用双重13 C 标记的乙烯基阳离子表明,作为该交换过程的机制,二碳炔 CC 2-单元在由三个阳离子甲硅烷基片段定义的三角形内旋转。因此,三甲硅烷基或二甲硅烷基锗基取代的乙烯基阳离子的动态结构与母体乙烯基阳离子质子化乙炔的情况相似。
Selective catalytic monoreduction of dichlorooligosilanes with Grignard reagents
Transition metal-catalyzed monoreduction of dichlorooligosilanes with Grignard reagents is reported. Among the examined catalysts, group 4 metal chlorides such as TiCl4 and Cp2TiCl2 gave the highest reactivity and good selectivity. The reducing power is effectively controlled by changing the catalysts and Grignard reagents to achieve sufficient selectivity depending on the oligosilane substrates.
Synthesis and Characterization of a Gold Vinylidene Complex Lacking π-Conjugated Heteroatoms
作者:Robert J. Harris、Ross A. Widenhoefer
DOI:10.1002/anie.201501474
日期:2015.6.1
Hydride abstraction from the gold (disilyl)ethylacetylide complex [(P)Auη1‐CCSi(Me)2CH2CH2SiMe2H}] (P=P(tBu)2o‐biphenyl) with triphenylcarbenium tetrakis(pentafluorophenyl)borate at −20 °C formed the cationic gold (β,β‐disilyl)vinylidenecomplex [(P)AuCCSi(Me)2CH2CH2Si(Me)2]+B(C6F5)4− with ≥90 % selectivity. 29Si NMR analysis of this complex pointed to delocalization of positive charge onto both
从金(二甲硅烷基)氢化物提取ethylacetylide配合物[(P)的Au η 1 -CCSi(ME)2 CH 2 CH 2森达2 H}](P = P(吨丁基)2 ö -联苯基)三苯基碳与在-20°C的四(五氟苯基)硼酸酯形成阳离子金(β,β-二甲硅烷基)亚乙烯基络合物[(P)AuCCSi (Me)2 CH 2 CH 2 Si(Me)2 ] + B( C 6 F 5)4 −选择性≥90%。该配合物的29 Si NMR分析表明,正电荷在β-甲硅烷基和(P)Au片段上均发生了离域作用。偏复杂后行容易相互转化的C1和C2碳原子(Δ ģ ≠ = 9.7千卡摩尔-1),通过金想必π-disilacyclohexyne中间体[(P)的Au η 2 - CCSi(ME)2 CH 2 CH 2的Si (Me)的2 }] + B(C 6 ˚F 5)4 - 。
STEINMETZ, MARK G.;UDAYAKUMAR, B. S., J. ORGANOMET. CHEM., 378,(1989) N, C. 1-15
作者:STEINMETZ, MARK G.、UDAYAKUMAR, B. S.
DOI:——
日期:——
Chloroplatinic acid catalyzed cyclization of silanes bearing pendant acetylenic groups
作者:Mark G. Steinmetz、B.S. Udayakumar
DOI:10.1016/0022-328x(89)85001-6
日期:1989.11
Chloroplatinicacidcatalyzed, intramolecular hydrosilylation of acetylenes of structure HMe2Si[CH2]nSiMe2CCR (R H or Ph, n = 2 or 3) proceeds via syn addition of the SiH group to the carbon triple bond to give, predominantly, cyclic products having an exocyclic rather than an endocyclic double bond. When n = 1 (R H), only recovered starting material is obtained. Closure of (4-hexynyl)dimethylsilane