Boron-Catalyzed Aromatic C–H Bond Silylation with Hydrosilanes
作者:Yuanhong Ma、Baoli Wang、Liang Zhang、Zhaomin Hou
DOI:10.1021/jacs.6b01349
日期:2016.3.23
Metal-free catalytic C-H silylation of a series of aromatic compounds such as N,N-disubstituted anilines with various hydrosilanes has been achieved for the first time using commercially available B(C6F5)3 as a catalyst. This protocol features simple and neutral reaction conditions, high regioselectivity, wide substrate scope (up to 40 examples), Si-Cl bond compatibility, and no requirement for a hydrogen
Transmission of electronic effects via a SiMe2 spacer in 4-mono- and 4,4′-disubstituted diphenyldimethylsilanes: 29Si and 13C NMR spectroscopy and PM3 semi-empirical calculations
作者:Cornelis A. van Walree、Xavier Y. Lauteslager、Andreas M.A. van Wageningen、Jan W. Zwikker、Leonardus W. Jenneskens
DOI:10.1016/0022-328x(95)05473-3
日期:1995.6
13C NMR studies were performed on series of 4-substituted phenyltrimethylsilanes and 4-substituted and 4,4′-disubstituted diphenyldimethylsilanes. Within each series linear relationships are found between the chemicalshifts and (a) the Hammett substituentconstants σp and (b) the PM3-calculated total atomic charges. It is inferred that the SiMe2 σ-type spacer weakly mediates substituenteffects in
对一系列4-取代的苯基三甲基硅烷和4-取代的和4,4'-二取代的二苯基二甲基硅烷进行了约29 Si和13 C NMR研究。在每个系列的线性关系被化学位移和(a)的哈米特取代基常数之间发现σ p和(b)的PM3计算总原子电荷。据推断,所述森达2 σ型分隔弱介导通过键偏振机构处于基态的取代基的影响。与4-取代的和4,4'-二取代的二苯基甲烷的可用数据进行的比较表明,SiMe 2基团比CH 2基团更好地传递电子效应。
Friedel-Crafts-Type Intermolecular C−H Silylation of Electron-Rich Arenes Initiated by Base-Metal Salts
作者:Qin Yin、Hendrik F. T. Klare、Martin Oestreich
DOI:10.1002/anie.201510469
日期:2016.2.24
An electrophilic aromatic substitution (SEAr) with a catalytically generated silicon electrophile is reported. Essentially any commercially available base‐metal salt acts as an initiator/catalyst when activated with NaBArF4 . The thus‐generated Lewis acid then promotes the SEAr of electron‐rich arenes with hydrosilanes but not halosilanes. This new C−H silylation was optimized for FeCl2 /NaBArF4 ,
亲电芳族取代(S Ë报道AR)与催化产生的硅电试剂。当用NaBAr F 4活化时,基本上任何市售的贱金属盐都可作为引发剂/催化剂 。然后,由此产生的路易斯酸会与氢硅烷(而不是卤代硅烷)一起促进富电子芳烃的S E Ar。针对FeCl 2 / NaBAr F 4对这种新的CHH甲硅烷基化进行了优化, 在低至0.5 mol%的催化剂负载下提供了良好的收率。该过程非常简单,与典型的Friedel-Crafts方法非常接近,在该方法中不需要添加碱来吸收释放的质子。
Formal Nucleophilic Silyl Substitution of Aryl Halides with Silyllithium Reagents via Halogenophilic Attack of Silyl Nucleophiles
作者:Hajime Ito、Eiji Yamamoto、Satoshi Ukigai
DOI:10.1055/s-0036-1590835
日期:2017.11
developed for the formal nucleophilic silyl substitution of aryl halides with silyllithium or silylpotassium reagents. Dimethylphenylsilyllithium reacted with various aryl halides to form the corresponding arylsilanes in moderate to good yields with concomitant formation of the disilanes under the optimized reaction conditions. Mechanistic studies indicated that this silyl substitution reaction progresses
Nickel‐Catalyzed Reaction of Aryl 2‐Pyridyl Ethers with Silylzinc Chlorides: Silylation of Aryl 2‐Pyridyl Ethers via Cleavage of the Carbon−Oxygen Bond
作者:Ying‐Ying Kong、Zhong‐Xia Wang
DOI:10.1002/adsc.201900949
日期:2019.12.3
Ni‐catalyzed C−O(Py) bond activation and silylation of aryl 2‐pyridyl ethers with silylzinc chlorides were carried out. This protocol allowed the 2‐pyridyloxy group to be substituted by a silyl group with short reaction times, mild reaction conditions, and good compatibility of functional groups.